An evolutionary outlook on motivation: Implications for the clinical dialogue

An evolutionary outlook on motivation: Implications for the clinical dialogue

Mauricio Cortina & Giovanni Liotti

Summary

Social instincts (motivational systems) among primates can be grouped into five major categories: systems that regulate ritualized dominance and submission displays (dominance hierarchies), systems that regulate care-seeking (attachment) and care-giving behaviors, systems that regulate cooperative behaviors toward members of a troupe, and systems that regulate sexual behaviors. Non-social instincts are, of course, also part of our evolutionary heritage. These ancient “reptilian” systems evolved to maintain physiologic equilibrium, regulate fight-flight-freeze responses, activate predatory behaviors, explore the environment, protect territorial boundaries, and reproduce sexually

While different forms of cooperation exist among primates, dominance hierarchies based on competition are the main form of social organization in nonhuman primates and cooperation is limited to dyadic interactions or small-scale levels of cooperation such as helping members with close genetic ties or defending territorial boundaries. Helping nonkin members of a group is rare. By comparison, altruistic cooperation in humans is directed at kin and nonkin members alike, and is widespread. Explaining how this altruistic form of cooperation evolved among our human (hominin) ancestors has been one of the great scientific challenges of our times. We address this question in two parts.

First, we describe four interrelated evolutionary strategies that emerged among our hominin ancestors that converged in our species to create ultracooperative adaptive strategies: cooperation in helping raise the young (cooperative breeding), the emergence enduring sexual bonds, the emergence of shared prosocial norms that supported en egalitarian ethos among nomadic hunter gatherers, and an very delayed sexual maturation and prolonged adolescence (life history strategies) that support cultural learning and the remarkable adaptive flexibility of our species.

Second, we turn to formal genetic explanations of the evolution of altruism and cooperation. The classic explanation for the origin of altruism and cooperation is based on genetic relatedness (kin selection), but genetic relatedness does not explain why cooperation toward nonkin is so prevalent in humans. We (and others) think that for this altruistic form a cooperative to emerge among ancestral bands of nomadic hunter-gatherers, selection pressures would have had to operate at the level of individuals and of groups (a multilevel view of selection). Groups with more altruistic cooperators prevail over less cooperative groups. A cultural form of multilevel selection emerged in our species based on shared social norms that support fairness and equality, and sanctions that kept alpha individuals and free riders from taking over the group.

High degrees of cooperation put strong selective pressures toward the development of sophisticated forms of intersubjective communication. The co-evolution of egalitarian forms of cooperation and advanced intersubjetive abilities created the conditions upon which humans were able to “sense” into the minds of others (empathy). The end result of this neo-mammalian evolutionary pathway was the emergence of language and a symbolic form of evolution based on learning (cultural evolution). Cultural learning is transmitted from one generation to the next, is therefore cumulative (is heritable) and produces cultural differences. Diversity and heritability will automatically create selection pressures, whether heritability is based on genes or on the transmission of learned cultural traits.

Motivational systems – reptilian, mammalian and neo-mammalian – emerged in phases during the course of millions of years. These different phases did not replace each other, but became re-organized in the brain at different hierarchical levels, as can be seen and inferred by its architecture. This evolutionary model of the human brain was put forward by Hughlings Jackson in the 1930’s and by Paul MacLean in the 1980’s. We explore some of the implications of this hierarchical, multi-motivational, cooperative-communication model of the mind for psychotherapy and psychoanalysis.

Introduction

Charles Darwin’s third book – The Expression of the Emotions in Man and Animals (1872) – was the first attempt to look at emotions, emotional communications and their underlying motives from an evolutionary perspective based on his theory of natural selection. His approach was nothing short of revolutionary, opening a new field of study. Unfortunately his approach did not bear much fruit until 150 years later, as can be seen by an explosion of articles and books that have appeared in the last few decades on evolutionary anthropology and psychology. Just for purposes of illustration, within the last few years there have been more than a dozen major books published that address the main themes that inform this essay. Namely the evolutionary origin of advanced forms of cooperation, altruism and cultural evolution (Boehm, 2012; Boehm, 1999; Bowles & Gintis, 2011; Boyd & Richerson, 2005; de Waal, 2009; Henrich & Henrich, 2007; Nowak & Highfield, 2011; Sober & Wilson, 1998; Tomasello, 1999, 2009; Wilson, 2012) and on the relationship between advanced forms of cooperation, social understanding and human communication (Hrdy, 2009; Malle & Hodges, 2005; Tomasello, 2008).

The birth of psychoanalysis was heavily influenced by evolutionary ideas. Unfortunately, Freud reverted to a pre-Darwinian notion that adaptations acquired during the course of development (phenotypes) could be directly inherited and passed on to future generations (genotype). Freud coupled this Lamarckian idea with Haeckel’s famous biogenetic law, “ontogeny repeated phylogeny”, and used these two concepts to support many of his core ideas (Solloway, 1979). For example, in Totem and Taboo Freud (1913) argued that during the prehistory of our species a band of brothers rebelled against a despotic father that had control of all the females, by killing and devouring him, and unleashing incestuous impulses. This alleged episode in the prehistory of our species became ritualized, according to Freud, in the form of a totemic meal. Guilt against incestuous and murderous impulses became regulated by rules of exogamy and incest taboos. The memory of this patricidal impulse was inherited and passed on to the next generations (Lamarckism) and then recapitulated (ontogeny recapitulates phylogeny) during development in the form of an Oedipal complex.

As outlandish as Freud’s ideas may seem, they contain a kernel of truth. One of the key questions in human evolution is how a social system based primarily on dominance hierarchies that are observed in all primates, was suppressed in favor of egalitarian forms of cooperation as observed among contemporary nomadic hunter-gatherers. We will present evidence supporting cultural continuity between contemporary nomadic foragers and ancestral foragers that began to exhibit evidence of modernity during the late Pleistocene, BP126,000 to 12,000 years Before Present (BP)[1]. Freud was on to something important when he postulated the idea that civilization (Freud use the German word kultur) came about by the repression of antisocial impulses. Nomadic foragers had to “suppress” dominant alphas and free riders in order to achieve high levels of collaboration and mutuality, one of the central hallmarks of our species (Bowles & Gintis, 2011; Henrich & Henrich, 2006; Tomasello, 1999, 2009). As we will explain later, it is likely that the main motivation toward egalitarianism was driven by the need to coordinate group hunting expeditions and insure meat would be shared equally among members of nomadic bands after hunting large game, (Boehm, 2012; Boehm, 1999).

Within psychoanalysis, Darwin’s natural selection approach finally bore fruit when John Bowlby put attachment theory within a modern evolutionary framework (Bowlby, 1969/1982, 1973, 1980). Slavin & Kriegman (1992) published another important book using modern evolutionary theory based on the work of the distinguished evolutionary thinker Robert Trivers that focused on parent-offspring conflict (1974) and the evolution of altruism through mutual and conditional forms of reciprocity (Trivers, 1971). As we will note later, while conditional forms of reciprocity such as “Tit for Tat” strategies (Axelrod & Hamilton, 1981)may have played a role in the evolution of altruism and cooperation, what is characteristic of the human form of cooperation and altruism is that it can be unconditional and does not depend on a direct “Tit for Tat” form of reciprocity (Bowles & Gintis, 2011; Henrich & Henrich, 2006). Humans will spontaneously help strangers in distress or take care of the sick and the disabled without any expectation of reciprocity, behaviors that can already be seen in 18 month-old toddlers (Tomasello, 2007). No other species displays this amount of helpfulness toward conspecifics (other members of their species) with which they do not have a close genetic relationship (Bowles & Gintis, 2011; Boyd, 2006; Clutton-Brock, 2009). Langs’ theory of emotion processing was yet another attempt within psychoanalysis to adopt a modern evolutionary framework (1996). Cortina and Liotti (2010) have introduced an evolutionary approach that focuses on the relationships between attachment, cooperation, intersubjective sharing and social understanding. 

Joseph Lichtenberg pioneered a multimotivational model that replaced Freud’s outdated drive theory (1989; Lichtenberg, Lachmann, & Fosshage, 2011). While he and his colleagues derived their model by drawing primarily from infant observation and research, there is a close resemblance to the model we are putting forward in this essay. In their latest look at motivational systems (2011), Lichtenberg and his colleagues come up with seven basic systems. The regulation of physiologic needs, attachment, caregiving, sexuality, exploration/competence, an aversive defensive system, and an affiliative system that they think is connected to groups. As far as we know, the only other multimotivational model in psychoanalysis has been put forward by the Spanish psychoanalyst Hugo Bleichmar (1997). Except for a book chapter (Bleichmar, 2003), his work unfortunately has not been translated from Spanish, Within the organizational psychology literature the psychoanalyst and anthropologist Michael Maccoby (1988) has also provided a multimotivational model. Despite important differences, there is a substantial overlap among these different multimotivational models.

One of the most prominent applications of a Darwinian approach to motivation and emotions outside the purview of psychoanalysis has been the work of the distinguished neuroscientist Jaak Panksepp (1998; 2012). There has been some cross-talk between Panksepp’s neuroevolutionary approach and psychoanalysis (Solms & Panksepp, 2012). In his latest book Panksepp describes six systems (2012). A seeking system that explores the environment and seeks novelty, a fear system, a rage system, a lustful/sexual system, a caregiving/nurturing system and a system that reacts with panic or grief when caregiving is unavailable or is lost.

Domain specific and domain general adaptations

Using a modular-computational model Cosmides and Tooby have proposed a social exchange model in which the evolution of sociability is one of many specialized adaptations (modules) that are assembled in the brain as discrete units (Cosmides & Tooby, 1987, 1997; Cosmides, Tooby, & Barkow, 1992). We share with Cosmides and Tooby an evolutionary approach based on natural selection, but we, as others, question the method of explaining almost every aspect of the human condition as the expression of specialized adaptations to our ancestral environment (Buller, 2005; Richardson, 2007). One of the unfortunate results of this approach is a proliferation of specialized modules. Up to thirty modules (and counting) have been proposed by different authors using a modular/computational approach (Buller, 2005). Social complexity brought about by advanced forms of cooperation and communication required enormous adaptive flexibility (Bjorklund & Rosenberg, 2005) and the ability to collaborate in joint tasks (Tomasello, Carpenter, Call, Behne, & Henrike, 2005). In turn, this required a very slow maturation and prolonged childhood and adolescence to integrate vast amount of information distributed among cognitive, perceptual, emotional and memory brain functions (Thompson & Nelson, 2011). This feat of integration is clearly the result of a domain general adaptation. The degree of social complexity and adaptive flexibility of our species could not be the result of domain specific modular adaptations.

Definition of terms

Following Lichtenberg (2005) we will use the language of motivational systems, rather than the traditional concept of instinct or drive. The classical concept of instinct or drive seldom makes reference to the specific goals and emotional cues that activate and temporarily “deactivate” instinctual behaviors (there is a constant shift in motivational system from being in the foreground to being in the background). Some of these emotional cues are felt and some are not. All these components of instinctual behaviors function as a system that is closely regulated and monitored, not unlike other physiologic systems in the body. The traditional concept of instinct also does not always emphasize the enormous importance of the role of experience, which allows the organism to respond flexibly to different environments. This experience is carried forward during development as a series of mostly unconscious expectations coded at implicit levels (Cortina & Liotti, 2007; Fosshage, 2005; Renn, 2012).. Nonetheless, we will occasionally lapse into the old language of instinct for the sake of brevity and to avoid the repetitive use of the more accurate, but more cumbersome language of motivational systems. 

The word altruism will be used for helping behaviors insofar as they incur a direct cost in fitness to the donor. In other words, the donor would be better of or would have increased his fitness if he or she withheld from the altruistic act. In the evolutionary literature a distinction is made between distal (phylogenetic) and proximal (ontogenetic) levels of analysis. It is important to keep this distinction in mind in regard to the evolution of altruism and cooperation, since a great deal of confusion is generated when these two levels of analysis are conflated. From a distal evolutionary perspective, altruism refers to the way altruistic allele (gene) is selected among different populations within a species in competition with a selfish gene[2]. From a proximal psychological-motivational perspective, altruism refers to way an altruistic gene activates or deactivates specific altruistic motives and behaviors within individuals. For example, let’s say that through a distal process altruistic gene(s) are selected because they confer greater survival value to those individuals who have this gene(s) than to those individuals who don’t. Through a complex biological process that involves the expression DNA regulated though epigenetic mechanisms such DNA methylation (Szyf & Bick, 2013) that turn genes on and off, altruistic gene(s) will ultimately cause mothers who have these genes to experience powerful positive feelings toward their offspring, so that these mothers will be highly motivated to care and protect them, that is, proximal causation.

Some models of selection are altruistic in an evolutionary distal sense but not in psychological-motivational proximal and some forms of cooperation are not altruistic at all. Kin selection is an example of the former. Some evolutionary theorists question whether kin selection is “truly” altruistic since it is based on the selection of altruistic genes among individuals who have close kin ties. From this distal perspective, some argue that kin-based selection is a prime example of genetic nepotism “selfish genes” pursuing their own reproductive ends through altruistic means (Dawkins, 1976/1989). However, if we look at kin selection from a proximal psychological perspective, helping behaviors between close kin behaviors are clearly altruistic. Take the example of mothers and their offspring that we just mentioned. Maternal instincts can be quite fierce, and mothers of many species of mammals (including humans) and birds will sacrifice their lives defending their offspring from predators or from other serious threats.

Reciprocal altruism (Trivers, 1971) is an example of a conditional form of cooperation that is not altruistic in a distal nor in a proximal sense, and many think the term is a misnomer. Reciprocal altruism is a direct form or cooperation based on a conditional strategy “I will help or cooperate with you if you help or cooperate with me, but will stop cooperating as soon as you do not reciprocate”. This strategy helps explain how many forms of cooperation might have evolved (particularly in the human case as we will see), but from a distal perspective this form or mutualism does not involve a sacrifice for the reciprocating pair, hence by definition it is not altruistic. From a proximal psychological-motivational perspective, reciprocal altruism it is not based on an altruistic motivation, but rather on a pragmatic-utilitarian calculus in which individuals select counterparts who “play fair”, a calculus that does not involve sacrifice. To avoid confusions in regard to altruism and cooperation, it is important to keep in mind the distinction between distal and proximal levels in the analysis of causation.

We will be addressing two forms of cooperation. One form of cooperation might be described as a form of enlightened self-interest (sometimes referred to as a weak form of reciprocity). We cooperate because it is mutually advantageous to do so. Another form of cooperation is altruistic. This altruistic form of cooperation involves a cost or sacrifice (sometimes referred to as a strong form of reciprocity). The extreme example is saving the life of a person even at the cost of our own life or taking it upon oneself to sanction or expose violations of shared social norms (the whistle blower). We usually think of these peoples as heroes, but here are myriad examples of less costly forms of altruistic cooperation that we see routinely such as taking the time to give direction to a stranger, giving a seat in a train or bus to an older person, mentoring a colleague, helping a neighbor by shoveling his walkway. All these examples can involve minor costs but they are altruistic. We do this for no other reason that the pleasure it provides us. The motivation is intrinsic (which we will refer to as a cooperative and social engagement system) and we are not looking for recognition or expect reciprocity. Humans excel in this form of altruistic cooperation. But not only is it a matter of the quality of cooperation, it is also a matter of quantity and scale. Human cooperation is not limited to dyadic or small group interactions and involves large-scale enterprises such engaging in warfare, creating institutions, multinational commercial transactions or large-scale scientific projects across international boundaries. Perhaps with the exception of a few highly social insects such as ants, bees and termites, this type of large-scale cooperation and social complexity is unparalleled in the natural world (Wilson, 2012). Explaining how these type of altruistic cooperation evolved in our species is a central theme of this essay.

Organization of the article

The remaining article is divided in to four sections. The first section attempts to explain how four interrelated evolutionary processes might have converged to create an ultra-cooperative evolutionary survival strategy in our species, and how this highly cooperative strategy might have coevolved to develop an intersubjective system of communication, social understanding and empathy (the ability to sense into the minds of others). The co-evolution of cooperation and social understanding sets the stage for the emergence of language and symbolic culture. We complement this explanation with a very brief description of different selection strategies operating through natural selection of alleles (distal models of causation). In addition to kin selection, direct models of selection based on reciprocity and indirect models of selection based on reputations, we explain why a multilevel group selection model might have played prominent role in the emergence of social norms and a new cultural form of selection based on learning. A multilevel model of selection is a model in which selection operates simultaneously at the level of genes, individual organisms and groups. Based on the work of several prominent evolutionary thinkers (Bowles & Gintis, 2011; Boyd & Richerson, 2005; Henrich & Henrich, 2007; Wilson, 2002; Wilson, 2012), we think that selection operating within groups and between groups was essential for the emergence of social norms and cultural evolution. We conclude this section with the fate of dominance hierarchies in the human ape.

In the last two sections we will examine the hierarchical nature of our evolutionary legacy as it has been organized within the human brain/mind, and how this model might help explain how complex cumulative trauma and the relation between intersubjective communication, attachment and cooperation.

Steps toward ultracooperation and the emergence of the human mind

In the next section we provide a very condensed explanation of how four interrelated evolutionary strategies worked to produce an ultracooperative type of social organization, and a strong motivation to develop affiliative ties with kin and nonkin members of nomadic hunter-gatherer societies[3]. We will also explain how and why these evolutionary strategies put strong selective pressures for the development of intersubjective abilities that helped in communicating and sensing into the minds of others (empathy). These four evolutionary strategies are:

1. A system of cooperative care by which others (“alloparents or allomothers” from the Greek allo which means other) assist mothers in the care and provisioning (feeding) of young children—formally known as cooperative breeding.
2. A type of sexual bonding (pair bonding) that led to more stable and durable ties.
3. A type of cooperation that led to the emergence of shared egalitarian social norms.
4. A very prolonged period of development (the most prolonged of any known species) that supported developmental plasticity and adaptive flexibility.

An extension of the caregiving system (or why “it takes a village”)

Cooperative breeding was first studied in some species of very social (“eusocial”) insects such as ants, bees and termites (Wilson, 2012) but it is its presence in primates that makes it significant for understanding human evolution (Hrdy, 2009). In the vast majorities of mammal species, only mothers care for their offspring until they become independent (“independent breeders”). For instance, chimpanzee mothers will not allow other members of the group even to get close to her infant in the first six months of life. Only in humans and a few other species of highly social mammals do mothers allow others to help in care of their offspring. Among contemporary hunter- gatherers other caretakers can be a grandmother, a male partner that has developed a stable bond with the mother, and older sister, as well as other mothers who may not be kin-related (Hrdy, 2009). This level of trust in other members of the group is rather extraordinary given the high level of infanticide that exists among many species of primates (Hrdy 2009). For instance, Cheney and Seyfarth (2007 pp. 40-41) report that infanticide exceeds predation as the major cause of death among baboons. While many factors account for infanticide in primates, most evolutionary thinkers attribute it to the very nature of very competitive societies in which primates live, and an impulse to get rid of potential rivals. As we will explain shortly, with the gradual shift toward more durable pair bonding among our hominin ancestors, males began to participate in the care of the young, an extension of the protective role that had been exclusively maternal (Chapais, 2008) and greater tolerance between males begins to develop (see below). The net effect is a diminished threat of infanticide that allows mothers to let others assist in the care and provisioning of their offspring.

It takes 13 million calories to rear a human from birth to nutritional sufficiency (Hrdy, 2009, p. 101) and humans of all primates have the most costly, largest, slowly maturing infants. Alloparents bear heavy costs when they participate in the care and feeding of juveniles with whom they may or may not have a close genetic connection. What benefits could possible offset these high costs? Human mothers that are freed from the exclusive care and feeding of their young can begin to participate more fully in foraging activities, and this participation might have had a large impact on the survival of these small nomadic societies. At least half of the calories consumed by hunter-gatherer societies come from the foraging activities of females (Hrdy, 2009, p, 106- 107). Females contributions, particularly the role of post reproductive women, has been well documented in several ethnographies of extant nomadic hunter-gatherer societies (Hawkes, 2004; Sear & Mace, 2008). This contribution becomes synergistic with the extensive mutual aid system that prevails among nomadic hunter-gatherers and ensures that the meat form big game hunting will be shared more or less equally among the band (see below). We agree with Hrdy that females’ contributions to contributing to the survival of our hominin ancestors is an important part of the prehistory of our species that has not received the attention it deserves. But its significance is becoming evident in developmental agencies from around the world that serve impoverished communities. Supporting women’s education and ability to participate actively in the economic life of their communities is one of the best ways to lift these communities from poverty[4].

There is another factor that helps explain why cooperative breeding might have taken hold among our human ancestors. While lactating, mothers are generally less fertile, and alloparenting allows human mothers to wean their babies earlier and make them available for having another infant. Chimpanzees who do not have this help wean their offspring until they are 5 or 6 years old. This has a very large impact on fertility rates of human mothers in comparison to our chimpanzee relatives. Before modern contraception methods were introduced to nomadic hunter-gatherer societies, human mothers conceived on an average of every 3 years, while chimpanzees conceive an average of every 6 to 7 years (Hrdy 2009).

Cooperative breeding promotes the development of intersubjective communications 

As significant as the effects of cooperative breeding are for the micro economies of nomadic foragers and the fertility rates of human mothers, the effects on the development of infants’ communicative abilities might have been of even greater evolutionary significance. Having many alloparents with whom to interact at an early age might have been the main factor that accelerated the development of infant communicative abilities and an important piece of the puzzle of why humans intersubjective abilities and communication are much more developed than in other primates. This is quite evident early in development by the charming “proto-conversations” between mothers and infants –the back and forth “ooing and aahing” that take place way before infants’ learn to speak their native language (Bateson, 1971; Beebe & Lachmann, 2002; Trevarthen, 1980).

There are several sources of evidence that support the idea that an early enriched social environment has profound effects on the development of intersubjective communication and the ability to understand the perspective of others later in life (Cortina & Liotti, 2005; Hobson, 2004; Hobson, Chidambi, Lee, & Meyer, 2006). Hrdy (2009) notes that when chimpanzees are raised in captivity or in close contact with humans, they develop many more abilities to communicate than those observed in their natural habitat. For instance, chimpanzees don’t point in the wild, but chimpanzees that are raised by humans often learn to use pointing to make requests, although they never learn to point for the sake of sharing an object with others, as human infants do by the time they are 12 months old. (Tomasello, Carpenter, & Liszkowski, 2007). When infant chimpanzees are exposed to the rich type of social interaction provided by humans, it pushes the limits of chimpanzees’ capacity for intersubjective communications to unsuspected degrees.

Tetsuro Matsuzawa at the Primate Research Center at the University of Kyoto had worked with Ai, an African-born chimpanzee over the course of thirty years, and so gained her trust that Ai did something that chimpanzee mothers would never do in the wild. She let Matsukawa have access to her first-born infant Ayumu. Matsuzawa was immediately rewarded by being able to make an important observation. Like human infants, Ayumu had REM induced smiles while she was asleep—sometimes referred to as a “practicing” smile. But a few weeks after birth Ayumu began showing a social smile, and she kept smiling to Matsukawa and her mother with full-blown social smiles, much like human babies do, a behavior between mothers and infants that had not been recorded in the wild before. One of Matsuzawa’s students, Masako Myowa thought that if babies were smiling early on, they might also be able to imitate gestures as Meltzoff and Moore’s famous experiments had shown in human newborn babies (Meltzoff & Moore, 1977). Using the same intuitive approach she learned from her teacher to probe the extent to which chimpanzees can interact socially after birth, Myowa was able to show with an infant chimpanzee that had lost her mother soon after birth, that they could protrude her tongue and imitate Myowa’s funny gestures. But there is a catch to this story. The Kyoto Primate staff repeated the same experiment with other newborn chimpanzees, and the infant chimpanzees continued to smile back and imitate their human caretakers. But suddenly at 12 weeks, the infant chimpanzees seemed to lose interest in their humans’ smiles, silly faces and gestures and stopped smiling and imitating them. It seems that the Kyoto group had pushed a type of social interaction to its very limit. Infant chimpanzees get close, but they cannot bridge the 6 to 7 million-year gap when chimpanzee and our hominin evolutionary paths began to diverge.

Supporting this view is the remarkable observations made in colony of rhesus monkeys located in Poolesville, Maryland headed by Stephen Soumi and colleagues in (Ferrari, Paukner, Ionica, & Suomi, 2009). The team observed and recorded a type of intersubjective sharing and eye gazing in mother-infant dyads that begins soon after birth. This form of intersubjective exchanges was thought to be rare or nonexistent among nonhuman primates. But after a month this type of intersubjective communication suddenly stops. At that age, infant monkeys begin to interact with their peers in rough and tumble play. Soumi speculates that this type of intersubjective communication does not serve a useful purpose in rhesus monkeys in which peer relations prepare juvenile members to adapt to dominance hierarchies that play such a major role in their social life (personal communication with the first author). Extensive alloparental care might have started us in this evolutionary path by providing the babies of our human ancestors with many opportunities for rich social interactions. As this intersubjective matrix began taking hold generation after generation through cooperative breeding, (and aided by the need to cooperate equals) it put us on an evolutionary path that led to the development to the ability to understand the intentions emotions gestures, and eventually, the minds of conspecifics (members of the same species).

Burkart and van Schaik (2009) developed another line of research that strongly supports the hypothesis that cooperative breeding and alloparental care led to more advanced forms of intersubjective communication and social cognition by comparing three closely related species of new world monkeys that vary in the degree to which they exhibit alloparental care. The first group of species, the tamarinds and marmosets, belong to the Callitrichid family and are full-fledged cooperative breeders combining care for the young with provisioning. The second species, the capuchin monkeys belong to the Cebine family and exhibit a modest degree of shared alloparental care with minimal provisioning. The third species, the squirrel monkeys – also members of the Cebine family – alloparental care is very limited or nonexistent (they are independent breeders). Burkart and van Schaik predicted that tamarinds and marmosets would outperform squirrel monkeys (independent breeders) in social cognitive measures but not in nonsocial cognitive tasks. Capuchin monkeys, who exhibit some cooperative breeding behaviors, would be in the middle. It was also predicted that the Cebine family of capuchin and squirrel monkeys would outperform tamarinds and marmosets in the nonsocial domain, due to the fact that they have a larger brain size relative to their body size—general intelligence and larger brains are in general highly correlated (Deaner, van Scahaik, & Johnson, 2006).

To compare social cognition (intersubjective abilities) they used 4 measures: attentional bias, gaze understanding, visual contextual learning, plasticity of vocal calls, and teaching-like abilities. To compare nonsocial cognition they used 7 measures such as tool use, stages of object permanence, working memory and responses that require delayed gratification in order to solve a problem—the effects of delayed gratification to solve nonsocial problems are well supported and includes a recent meta-analysis (Deaner et al. 2006). Consistent with the hypothesis, tamarinds and marmosets systematically and significantly outperformed their capuchin and squirrel monkeys in the social cognitive domain, but not in the nonsocial cognitive domain. It is important to emphasize that tamarinds and marmosets outperformed capuchin and squirrel monkeys in social cognitive measures despite having a smaller brain. As predicted, capuchin monkeys that have some elements of cooperative breeding are somewhere in the middle in social cognitive skills. This is a very significant confirmation of the hypothesis that alloparental care promotes the development of social cognitive skills that are needed for intersubjective communication to flourish.

It is very likely that the same phenomena has been at work with dogs, who have a long history going back at least 14000 years or more of living with humans, and explains why dogs have some remarkable human-like social skills (Hare & Tomasello, 2005). Through a process akin to domestication, human infants, raised and exposed for hundred thousands of years to multiple caregivers were able to develop intersubjetive skills that helped human communications and social understanding (Hrdy, 2009). It is also from this fertile intersubjective ground that language and conceptual thought is able to blossom. Exploring the relationship between intersubjectivity and language is beyond the scope of this article (see Cortina & Liotti, 2010; Hobson, 1998, 2004; Tomasello, 2008; Trevarthen, 1980)

How enduing sexual pair bonds (pair bonding) contributed toward the type of family structure and group composition observed among hunter-gatherer societies 

Chimpanzees and bonobos live in large mixed sex groups that mate promiscuously (particularly the bonobos) and have short term mating patterns. Males and females copulate with several mates and there is no stable breeding bond (Chapais, 2008). When the females reach sexual maturity they move to new groups (their species solution to the incest problem) while the males stay in their natal group. In chimpanzees this social organization leads to extensive patrilines of males that include grandfathers, fathers, uncles and brothers. Remarkably, these patrilines do not recognize themselves as kin so that this genealogical structure is “socially silent” (Chapais, 2012). The significance of this lack of kin recognition is that it makes other males potential rivals. Chimpanzees do not form “friendships”, at best they develop strategic partners to protect their rank or use these alliances to take over higher-ranking individuals (de Waal, 1982). Grooming plays an important role in this process by softening conflicts, and by helping create and maintain new alliances (de Waal, 1989).[5] Sometime during the course of human evolution longer term pair bonding between males and females and stable breeding patterns emerged as an evolutionary innovation – an innovation that has occurred in other species of primates and birds but is rare. According to Chapais, the most important consequence of long lasting pair bonding is that as fathers begin to participate in the caregiving of their offspring they begin to recognize them as “one of their own” –and vice versa. Slowly, pair bonding begins to reveal the underlying genealogical structure of kin relations. For instance, if a daughter forms a pair bond with a male from another group, the father can now recognize his daughters preferred mate as an affine, that is, as a familiar individual who can be tolerated and doesn’t pose a threat to his exclusive relation to his mate. Other effects of enduring pair bonds became extended to sibling relations and to maintaining family relations when family members migrate to other groups because of marriage or other reasons. The combined effect of these evolutionary innovations brought about the multifamily composition of humans, a kinship system probably emerged in fits and starts among our hominin ancestors. This extension of social recognition among group members began to create a state of mutual tolerance among males and possibilities for cooperation that had not existed before. In this growing social network, males were able to circulate more freely between groups (Chapais, 2008). The ability of band members to interact with other members of hunter-gatherer groups created possibilities for commerce, mutual learning, and as we will see later, mutual aid in times crisis. The resulting accumulation of cultural knowledge led to the emergence of behavioral and cultural modernity during the Late Pleistocene period (Tomasello, 1999, 2008).

A study of 37 nomadic hunter gatherer groups (n = 5067 individuals) from all over the world by Hill and the co-authors (Hill et al., 2011) confirms Chapais predictions of the composition of multifamily groups in nomadic societies, as well the effects on the development of kinships networks and of residence and co-residence patterns (who stays or leaves a group and how stays in contact ). Contrary to what we see among other primates, when family members do stay in their natal group (such as brothers and sisters) they often maintain life long ties. The significance of enduring sexual bonds for human evolution is that it supported the formation long-term relations that are necessary to sustain cooperation over the long haul. The net effect was to produce changes in residence patterns within natal groups, and large interactive networks of family related and unrelated individuals between different groups.

We close this section on pair bonding with two points. First, the emergence of long-term pair bonding should not be read as implying that monogamy is normative for our species, and that other mating systems or institutions such as polygyny (one male to several females) or polyandry (one female to several males) are aberrant. Different species and different human cultures have produced many types of mating systems that have proven to be adaptive. Second, anthropologists have generally have held the view that small bands of nomadic hunter-gatherers were composed almost entirely by kin, and the high degree of altruistic cooperation observed in our species has generally been explained by kin selection (see below). But the Hill et al., study shows that most members within small nomadic bands are not kin-related. Therefore kin selection, as a sole evolutionary selective mechanism leading to altruism, cannot be the explanation of the extensive cooperation and egalitarian social organization observed in nomadic hunter-gatherers around the world.

From hierarchy to egalitarianism (or how nomadic hunter gathers got rid of bullies and solved the free rider problem)

During 99 % of the life of our species (if you star counting the appearance of Homo erectus 1.8 million years ago, considered by many our first fully Homo ancestor) we have lived as nomadic hunter-gatherers. To understand human evolution it is essential to have an approximate idea of what that nomadic life might have been like. Human behaviors and attitudes do not fossilize, and any understanding has to be come from the very scant traces of fossilized bones and artifacts left behind and ethnographic studies of modern nomadic foragers that have had minimal contact with modern civilization (Boehm, 2012; Boehm, 1999; Hill et al., 2011). Ethnographies of extant nomadic hunter-gatherer societies serve as the closest model we have as how human hominin ancestors lived and survived during the Pleistocene—particularly during the Late Pleistocene (120,000 to 12,000 BP), when cultural and behavioral modernity makes its appearance in the archeological record

If Sarah Hrdy is the undisputed champion in highlighting the importance cooperative breeding had in evolution of our species, Christopher Boehm has played a similar leading role in helping us understand how and why our human ancestors were able to transition from a social organization primarily based on dominance hierarchies to a highly cooperative social organization based on a shared egalitarian ethos that emerged sometime during the Pleistocene era. Boehm brings a unique skill set to this endeavor. Trained as a cultural anthropologist, he did field work studying egalitarian tribes in New Mexico and Montenegro and was trained by Jane Goodall, the legendary pioneer in studying chimpanzees in the wild (Goodall, 1986). Boehm has continued the work of Goodall doing annual field trips to the Gombe national park in Tanzania. 

Boehm (1999, 2012) has carefully reviewed the ethnography of 337 nomadic hunter-gatherers studied by anthropologists in the past, selecting and weeding out cases that had significant contact with modern civilizations or missionaries. Boehm also eliminated ethnographies of large groups of nomadic hunter-gatherers and cases in which nomadic foragers spend time in a permanent village. That left 150 cases that he called “Late Pleistocene appropriate foraging societies”. Of these 150 cases, only a third have been systematically coded and studied by Boehm using criteria that he has been refining over time. These nomadic foragers live in mall bands of 20 to 30 individuals comprised of multi-family groups as well as group members that are kin related (Hill et al., 2011). The most significant findings from this review – that confirms what most anthropologists have come to believe – is that despite huge differences in climates, from frigid Arctic tundra to sweltering tropical forests, and many cultural differences, without exception all nomadic groups are fiercely egalitarian and they actively shame, ostracize and punish individuals who deviate form the egalitarian ethos. This fact alone begs for an evolutionary explanation.

Anthropologists have noted similarities between contemporary hunter gathers and what is known of our Late Pleistocene ancestors, such as similar hunting tools such as stone flakes attached to wooden shafts, harpoons, traps and nets, sometimes described as “gadget technologies” (Kuhn & Stiner, 2001). But what perhaps comes closest to a “smoking gun” in anthropology, showing evidence of cultural and cognitive continuity between nomadic hunters separated by 40,000 years or more, has been the recent discovery by d’Errico and his team of a many artifacts found in the Border Cave, near the border of Swaziland in South Africa (d’Errico et al., 2012). All these artifacts and bones have been carefully dated and are between 39,000 to 44,000 Before Present (BP). They include bone tools shaped in long shafts for scrapping that are finely decorated in the form of a spiral with red pigment, and beads made of ostrich eggshells used as necklaces. Other artifacts found are “digging sticks” and a “stick” bearing traces of a poisonous compound –similar to a tool used by the bushmen of the Kalahari desert to apply poison in their arrows. In addition 4 bones with notches were also found, that the team interpret as “tally sticks” used for counting. All these artifacts are remarkably similar to the art work and hunting tools used by contemporary bushmen people in Africa, and show that the inhabitants of the Cave Border in South Africa had achieved a level of cultural and technological sophistication that matches contemporary bushmen of the Kalahari desert (Balter, 2012b). These recent discoveries support Boehm’s speculation (2012) that the transformation toward a highly cooperative and egalitarian type of social organization took place during the late Pleistocene approximately 45,000 BP, but it might have been even more ancient given recent discoveries in South Africa dating 77,000 BP (Balter, 2011a).

As our homo ancestors left the relatively protected forest and river ravine environments and began to adapt to the open African savannah – beginning with Homo erectus 1.8 million years BP – the need to develop highly cooperative bands became essential for their survival. High levels of cooperation were necessary in order to share the spoils of animal scavenging, to protect against much more powerful predators, and to achieve a highly coordinated form of hunting and meat sharing with other members of the band on an equal basis, whether they participated in the hunt or not. Based on recent paleontological evidence, Boehm estimates that cooperative hunting of large ungulates (large hoofed mammals) might have been of relatively recent origin some 250,000 BP (Boehm, 2012, p. 313). It is not hard to imagine why this type of collaborative hunting and equal sharing of meat became the basis of an egalitarian form of life. 

As the ethnographies surveyed by Boehm vividly show, any attempt by other members of the group to take advantage of this system of sharing by not reciprocating in kind (the “free rider problem”), or trying to dominate the group (aspiring alphas and bullies), are immediately ridiculed or punished through different means, including shaming, ostracizing, and in extreme cases by murder (Boehm, 1999, 2012). The role the family of emotions that include shame, embarrassment, quilt and pride are powerful socializing tools that we and others think had a major impact in contributing to an egalitarian form of life among ancient nomadic foragers (Gintis, Bowles, Boyd, & Fehr, 2005; Henrich & Henrich, 2007). Evolutionary models show that the punishment of free riders, bullies and sociopaths is critical for an altruistic form of cooperation to evolve, but the punishment of bullies or free riders can carry a very large costs if left to a few individuals who singlehandedly who confront free riders or bullies (Gintis, 2003; Gintis, Bowles, Boyd, & Fehr, 2003; Henrich & Boyd, 2001). These models show that without sanctions free riders will exploit altruists, who will become extinct within a few generations.

We will return to this problem when we examine the issue from a purely genetic (distal) evolutionary perspective. For now we want to examine the problem from a psychological (proximal) perspective to show how the emergence of shaming emotions during human evolution very likely went hand in hand with the emergence of shared social norms that support communal values of equality and fairness (Gintis, 2003; Gintis et al., 2003). The argument is strait forward. Shared prosocial norms act like a social tax that is imposed on all members of the group (Boyd, 2006) and make the cost of sanctioning free riders and bullies a less costly proposition for any single individual who would act on his own. The “tax” idea is Boyd’ s way to explain a proposal by Samuel Bowles idea of “reproductive leveling” (Bowles, 2006). The “leveling” effect is created by cultural influences, such as shared social norms, that support equality and fairness and “level” the playing field for cooperative altruists, who otherwise will be wiped out within a few generations by individuals who pursue their own interests at the expense of others.

For shared social norms to have a major role in creating social change it is important that these norms become internalized as a set of mostly autonomic (unconscious) expectations. Once internalized, shared egalitarian values support the collective sanctioning of free riders and bullies by shaming and ostracizing those members who deviate form these shared ethos (Boehm, 1999). Shared social norms function by acting as a social glue that hold groups together by creating a sense of cohesiveness and group identity, in what Choi and Bowls (2007) have called a “parochial” identity that is the basis for an “us a us versus them” mentality.

The idea of “internalized” shared values that act like a social glue has been modeled mathematically by the economist Herbert Gintis (2003). The importance of shared social norms, values and attitudes was introduced to social psychology by the psychoanalyst Erich Fromm (Fromm, 1941) who tested this theory empirically a few decades later (Fromm & Maccoby, 1970). Fromm called these shared values and emotionally based attitudes “social character theory”. The main idea behind the theory is that a set of character based (emotional based) attitudes and values became shared by large number of individuals within a group or social class. According to Fromm “social character internalizes external necessities and thus harnesses human energy for the task of a given economic and social system” (Fromm, 1941, p. 284). In effect, people end up “wanting to do what they have to do” to prosper and survive under certain social and economic conditions (Fromm and Maccoby, p. 18). According to Fromm, shared attitudes and values are instilled by families, who function as “psychic agents of society” (Fromm, 1947 p. 68) and are internalized through a process socialization and assimilation that begins early in development and are reinforced by social institutions and ideologies (Fromm 1941, Fromm and Maccoby, 1970). 

Despite the existence of internalized values, there will always be individuals who defy or will not conform to these norms, and different types of sanctions or punishments are necessary to bring these individuals in line. Shared values and social sanctions support each other. Shared norms ensure that the cost of sanctioning does not fall on the shoulders of only a few individuals. Different forms of shaming, maintaining social reputations, and the threat of ostracism are sufficient to keep must trouble makers in check, as shown so clearly in ethnographies of hunter gatherers quoted by Boehm (1999). Without the emergence of shared social norms and social sanctions that shame or ostracize nonconformists, it hard to understand how and why prosocial motives and behaviors displayed toward members of a group toward who are not bound be kinship ties could have evolved.

Two caveats are in order. First, the argument being advanced is not that all shared social norms are adaptive and prosocial. We only have to look at the horrific example of Nazi Germany to show how a shared ideology based on wounded national pride and the invidious scapegoating of minority groups can lead to genocide and self-destruction. On a study that was never published in English, Fromm showed that only 20% of the people surveyed (using an in-depth interview) shared the Nazi social character (shared social values), but predicted there would not be enough of a resistance to Nazism due to social conformity of the rest of the population[6]. Second, maintaining adherence to shared values through different forms of shaming and threats of ostracism work informally (and effectively) in small groups such as simple hunter-gatherer, pastoral or horticultural societies. The evolutionary psychologist Robin Dunbar (2010) found that for informal social systems work when they are limited to approximately 180 people (“Dunbar’s number”). Sanctioning in complex societies with large urban centers requires formal institutions to be effective, but even in complex societies there has to be enough of common ground of shared values for institutions to have legitimacy, and institutions have to be perceived as having sufficient integrity for people to trust them. When these bonds of legitimacy and trust break down, societies begin got descend into anarchy and chaos.

Life history strategies support developmental plasticity and adaptive flexibility

Life history strategies (LHS) that tinker with the shortening or lengthening of developmental periods and the initiation and termination of developmental phases can have major evolutionary impacts and are frequently observed in the evolution of many species. Humans are no exception, and LHS have played a major role. According to Thompson and Nelson “nonhuman primates are considered to have four major life history strategies: infancy the juvenile period, a short adolescent period and the adult stage…..modern humans have “inserted” an additional stage: early childhood, which falls before the juvenile period, and they greatly elongated their adolescent stage” (Thompson & Nelson, 2011 p. 249-250). In addition, humans wean their infants earlier than chimpanzees and have a longer postreproductive period. The shorter weaning period in humans is connected with cooperative breeding. As other members of nomadic hunter gatherer groups participated in the feeding of infants, human mothers were able to wean their infants earlier—till the age of 3 among nomadic hunter gatherers In comparison chimpanzees wean their there infants until they are 6 years old. Following the weaning period around the age of 3, humans have added an early childhood (three to five). Adding an earlier childhood period to middle and late childhood has kept these childhood stages roughly equivalent to the “juvenile” period of chimpanzees and bonobos. Adolescence in humans is very prolonged in comparison with our ape relatives and even in comparison with our closest hominin relatives. Chimpanzees reach full sexual maturity and are fully developed by age 12, approximately the same age when Homo erectus reached sexual maturity. In contrast, humans reach full sexual maturity by of 18, by far the latest of any known species. Recent evidence shows that Neanderthals, who had brains as big or bigger than humans, reach sexual maturity by age 14. Interestingly our extreme form of elongated adolescence does not appear until the appearance of modern Homo sapiens roughly 150,000 years ago. Clearly, brain size alone does not explain the differences between humans and Neanderthals, and the finding that humans have a more prolonged adolescence and slow maturity that the Neanderthals suggest that the prolonged adolescence was selected to increase developmental plasticity of the brain and allow children and adolescents sufficient time to absorb the enormous amount of learning that is necessary to function as adults in rich cultural environments that humans are continually recreating.

In addition to adapting their natural environments, some species create their own environments. This is the important phenomenon of niche construction (Kendal, Tehrani, & Oding-Smee, 2011). Bees create beehives, beavers create dams, and ants create a complex interconnecting labyrinth underneath their ant holes. These niches are more or less static and do not change once they are made. In contrast humans create cultural environments that are constantly changing. The emergence of a cultural form of evolution created strong selective pressures toward making changes in LHS that supported developmental plasticity and adaptive flexibility (Bjorklund & Rosenberg, 2005).

Human live longer live than our African ape relatives and our extinct hominin relatives, the Neanderthals (Thompson & Nelson, 2011). A longer life span means a longer postreproductive period. Rather than remaining idle, postreproductive woman participate actively in the care of their grandchildren and other children that are not closely related family members. This is known as the “grandmother hypothesis” brought to out attention be Kristen Hawkes (Hawkes, 2004), yet another link in the chain of events that supported the emergence of cooperative breeding system in our species.

Conclusion 

Cooperative breeding and the development of enduring sexual bonds have emerged in species with small brains and without the benefit of the extraordinary accumulation of cultural knowledge we see in humans. We think cooperative breeding and pair bonding might have jump started a new cultural form of evolution that appears with the emergence of shared social norms and an egalitarian ethos that is universal among nomadic hunter. Life histories strategies had a major impact facilitating these changes by delaying sexual maturation and creating a very elongated period of development that gave infants, children and adolescents time to assimilate and learn a vast amount cultural knowledge needed to function as adults. All these cooperative trends put selective pressures on creating better modes of communication that preceded the emergence of language. Humans who anatomically would be identical to us appear approximately 150,000 ago in Africa. It took 70,000 years or more before human populations reached a level of density that allowed them to interact and learn from each and imitating cultural innovations such as tool making, cooking tips, artistic skills and musical instruments (Powell, Shennan, & Thomas, 2009)[7] that are first manifestations of social complexity.

We have suggested a sequence of events that seem plausible to us, but we may never be able to know how with any degree of certainty, when and in what order these and other different evolutionary and cultural innovations came together. Moreover, there are other important cultural innovations such as the harnessing of fire that appeared 800,000 BP have not discussed and had a major impact on human evolution (Wrangham, 2009). Whether these story lines or others turn out to have staying power will depend of course on new discoveries and new methods of inquiry. As formidable as these limitations and challenges are in the understanding the evolutionary history of our species, it should not stand in the way of putting forward narratives and models that can be tested and can lead to better narratives in the quest to understand human evolution. 

Genetic models of evolution and the emergence of cultural evolution

For these evolutionary strategies that we have described to have any credibility, at the very least they have to be consistent with the theoretical work that has been formalized mathematically within the past 80 years. Mathematical models examine the basic conditions (constraints) that allow natural selection to sort out whether cooperative and altruistic alleles (genes) will persists or will be wiped out by selfish alleles from the gene pool, or reach a stable dynamic equilibrium between both sets of alleles. These models help in pairing down the essentials, sometimes providing surprising insights. They can be then run as computer simulations and be put to the test with real life examples to see how realistically they conform to the natural world. In this section we will be emphasizing multilevel level model of selection because of its importance to human evolution While understanding the math helps, it is not essential, since these concepts can be translated into plain English.

Understanding the evolution of cooperation and altruism was named in a special issue by the editors of Science as one of the 20 most vexing scientific problems that remained to be solved (Kennedy & Norman, 2006). Since then, a growing consensus has been building toward a pluralistic perspective, identifying some key variables that lead toward the emergence of altruism and cooperation. From this pluralistic perspective, different evolutionary models are seen as complementary rather than competing evolutionary strategies (Bowles & Gintis, 2011; Henrich & Henrich, 2007; Nowak & Highfield, 2011; Sober & Wilson, 1998). Within each species, different selection strategies come together providing a path toward cooperation and altruism. As Sherrat and Roberts note “The problem of cooperation has now many solutions and its existence can no longer be classified as a puzzle…. Eventually, theory and observation will meet and we then we will really know which general explanations apply to the world around us (Sheraff & Roberts, 2012, p. 1305) 

We will discuss four main models that have been developed more or less independently form each other with a focus on explaining the human evolution: kin selection, a multilevel group selection model, direct and indirect forms of reciprocity. We will begin with kin selection also known as “Hamilton’s rule” in honor of the legendary evolutionary thinker William Hamilton who as a graduate student published and article that revolutionized our understanding of the evolution of altruism (Hamilton, 1964). The general idea is that altruism could evolve through natural selection because it conferred benefits of the altruistic act to close genetic relatives. Consequently the altruistic act helps the proliferation of alleles (genes) associated with the altruistic act. Think of it as a form of genetic nepotism. The insight can be expressed formally by saying that conferring a fitness benefit of b to another individual will evolve by natural selection if the benefit of b is more than the cost of c to oneself:

b > c

This relation is modified by a factor of r, (mathematically a “coefficient factor”), were r represents the genetic relatedness between the actor or donor b and the beneficiary c. The values of r will vary according to the degree of genetic relatedness. One half for siblings, since siblings share 50 % of their parents genes (r = 0.5), one quarter for nieces and nephews (r = 0.25), an one eighth for cousins (r = 0.125). This general formula is expressed with a simple mathematically equation known as Hamilton rule:

rb > c

The values for r will oscillate to close to zero for strangers to .5 for offspring or siblings, therefore altruism will evolve as long a rb - c > 0. The closer the relative is to the donor the larger the fitness effect because the genes of the donor are passed on to the close relative (measured by the value of r) and therefore stays within the gene pool. Hamilton called this indirect benefit “inclusive fitness”.

Hamilton’s rule explains most cases of altruism directed at kin, such as the care of offspring by parents observed in many animals and among humans, but its importance is far more general. According to Bowles and Gintis, Hamilton’s rule “captures the key mechanism to all models of the evolution of altruism, namely that an altruistic gene cannot proliferate if its bearers are no more likely to receive help from those with whom they interact than would occur by chance” (Bowles and Gintis, 2012, p. 49). All successive models of the evolution of altruistic behaviors share this positive assortment feature in which altruistic and cooperative members interact with others members of a group who are likely also to be cooperative and altruistic. The positive assortment among kin is probably achieved through physical cues such as family resemblance and odors, but also through the experience gained by growing up together. Altruistic members of a group who do not have close genetic ties cannot rely on physical cues to help recognize other altruists, and have learn to recognize fellow altruists through other means. This mainly happens through repeated interactions. Altruistic group members learn quickly who is likely to reciprocate and who wont. The end result is that this positive assortment feature leads to frequent interactions between cooperative altruists. All evolutionary models show that these ongoing interactions are essential to sustain cooperation on the long run.

This takes us to multilevel group selection models where groups are competing with other group for reproductive success. Group selection is a multilevel process involving several steps. First, there has to be mechanisms within groups to prevent free riders from taking advantage of cooperative altruists, otherwise free riders will eliminate cooperative altruists within a few generations (Sober & Wilson, 1998, pp. 18-30). Second, there has to be a diversity of groups with different mixtures of individual who carry altruistic alleles and individual who carry selfish (free rider) genes. Third, there has to be frequent contests between these groups for group selection to work. To understand how the first condition might have emerged (positive assortment mechanisms) within ancestral bands of hunter-gatherers), we need to go back to our previous discussion in regard social norms and sanctions. Shared social norms, reinforced by the power of shame and the threat of ostracism, insure that troublesome free riders or bullies will be kept in check or will be expelled from the group. These mechanisms of social regulation support an ongoing interaction (positive assortment) between cooperative altruistic within these groups and will tend to suppress or eliminate free riders. The idea is summarized by Gintis (2004):

Cultural complexity and the rapidity of cultural change…render the internalization of norms fitness-enhancing, so the genetic predisposition to internalize norms is an evolutionary adaptation. Moreover, agents who internalize norms tend to punish norm violators. Thus, conformity to social norms becomes fitness-enhancing, which renders the genes for prosocial emotions fitness-enhancing adaptations. The internalization of norms and the prosocial emotions permit large-scale cooperation among non-kin, setting the stage for the technological and cultural evolution characteristic of modern civilization (p. 58).

The third second condition requires frequent contests between groups. It has been generally believed than nomadic hunter-gatherer groups are generally peaceful and there would not be sufficient conflicts between groups for selective pressures to work at a group level. But a review of the ethnographic literature by the economist and evolutionary theorist Samuel Bowles, shows that nomadic hunter gathers groups battles are much more frequent than was believed, and these conflict can be quite lethal because of the nature of hand to hand combat (Bowles, 2006). When all these conditions of multilevel selection are met, group selection can overcome the strong selective pressures against the evolution of altruism in single groups. Add to these effects the emergence of cumulative cultural learning and a process of cultural differentiation between groups or tribes, and we can see why multilevel selection became such a powerful force during human evolution. Natural selection requires phenotypic variability, heritability and competition to work. It doesn’t mater whether variability is achieved through mutations or through learned cultural traits, as long as the effects of mutation or learned traits are stable and endure (are heritable) form one generation to the next (Boyd, Richerson, & Henrich, 2011; Henrich, Boyd, & Richerson, 2012; Henrich & Henrich, 2006).

Genetically based selection and culturally based selection operate under the same principles but through different means, but the effects on the speed of change are dramatically different. Genetically based selection produces changes that move at a snail’s pace compared to cultural selection that produces changes that move at the speed of light. Moreover, these two forms of evolution influence and each. The evolution of altruism in humans is as good example. Alleles that code for cooperative and altruistic behaviors emerge through mutations. But as we have seen, cultural innovations such as shared social norms may have had dramatic effect in the fate of these alleles during he course of human evolution, favoring the selection of altruistic genes. Other examples of gene-cultural co-evolution are probably abundant but until recently have not received much attention. One of the best known is the emergence of enzymes that metabolize lactose in cows milk, as milk become a basic staple in pastoral and horticultural societies in Europe during the early Holocene (12,000 to 5000 BP). A recent section Science magazine featured articles showing that genes that effect brain development are subject to ongoing selective pressures (Balter, 2005).

The gene-cultural coevolutionary model is a product of many scholars and researchers that have been building on each others work for the past 30 years (Boyd & Richerson, 2005; Cavalli-Sforza & Feldman, 1981; Durham, 1991; Lumsden & Wilson, 1981; Richerson & Boyd, 2005; Wilson, 2012). The model transcends fruitless debates in the social sciences at to whether human nature is hard wired, based on genes or the product of cultural differences. It is both; genes influence culture and culture influence genes. The end result is that cultural selection generates outcomes that are not seen in other animals and that our unique to our species (Boyd et al., 2011; Boyd & Richerson, 2005; Wilson & Wilson, 2007).

There is an extensive literature on direct and indirect forms of evolution that resists an easy summary[8]. We will limit the discussion to define the terms and their role during human evolution. Direct reciprocity refers to dyadic exchanges based on conditional forms reciprocity. Inspired by game theory, Trivers (1971) was the first to propose the idea, and called it reciprocal altruism, which as we explained earlier, is not really an altruistic strategy since it is based on calculus of whether a cooperative bid will be reciprocated in kind. The paradigmatic form of direct reciprocity are conditional strategies such as “Tit for Tat” form of reciprocity (Axelrod, 1984). Indirect forms of reciprocity (Alexander, 1987) are not based on direct exchanges but on a desire to associate and emulate with individuals in a group who are admired and have a good reputations. The idea is that being generous makes you look attractive when there is competition in choosing sexual partners. Selection by reputation could have become a very important as it became generalized to nonkin as an extra familial source of generosity. Ethnographies of nomadic hunter-gatherer societies reported by Boehm confirm that indeed, the power of reputations are important in very important in these small societies were gossip plays a large role and everybody knows about others peoples business (Boehm, 2012).

Interestingly, examples of direct and indirect forms reciprocity have been mostly documented in humans (Henrich & Henrich, 2006; Henrich & Henrich, 2007) and very few examples have been observed on other social animals (Clutton-Brock, 2009; Hammerstien 2003).

The reason why examples of direct and indirect forms of reciprocity are mostly confined to our species may have to do with the same reasons why the emergence of shared values were key for multilevel group selection to blossom. Just as the emergence of shared values became a central step in supporting group level selection, the emergence of a moral order was equally important for rules of fairness that support direct forms of reciprocity (such as “Tit for Tat” strategies) or for the power of reputations (indirect forms of reciprocity). Boehm (2012) believes that morality emerged through the power of maintaining social reputations and imitating successful individuals. We think that the key factor was the emergence of shared values and social norms. Only when these values had become internalized did the power of reputations have an effect in shaping social selection processes. Many experiments done in different countries and different cultures show just how important and widespread norms of fairness are in daily life of people (Henrich et al., 2005).

The dark side of multilevel group selection

One of the consequences of developing strong selective pressures towards the emergence of in-group “niceness” was a tendency for out-group “nastiness”. The motivation to affiliate and identify with one’s own group led to a parochial form of solidarity and a tendency to see other groups as competitors or rivals (Choi & Bowles, 2007). Evolutionary theories are for the most part about tradeoffs, about cost and benefits. This parochial or tribal form of in-group altruism and cooperation came at the cost of kicking competition to a new level among populations of small groups of nomadic hunter gatherers that lived in relative proximity to each other (Choi & Bowles, 2007), and as we just mentioned, there is growing evidence that these conflicts between hunter gatherers bands were much more lethal than what has generally been assumed (Bowles, 2009; Bowles, 2012). As gruesome as some of these pitched battles most have been, they pale in comparison to the destructive potential of modern forms of human conflict. The capacity to inflict massive casualties on military foes and on innocent civilian populations has been growing exponentially over the millennia as organized armies become equipped with increasingly more lethal weapons. It is ironic that the same evolutionary process that created in-group solidarity and altruism is the same processes that created competition between groups and an “us versus them” mentality, a mentality that in its most malignant expression leads to genocide and modern warfare.

Destructive conflict and war are not inevitable

Conflict and warfare is not necessarily the only outcome of multilevel group selection. There is clear evidence from the groups of nomadic hunter-gatherers that have been closely studied by anthropologists within the last 100 years that they can a do engage in many forms of peaceful commerce (Weissner, 1982). In fact it was probably these exchanges between groups that allowed our nomadic ancestors to reach cultural modernity (that we will define shortly) during the late Pleistocene. Populations of hunter-gatherers grew very slowly during the late Pleistocene before they could reach a critical population density that allowed for ongoing exchanges among ethnically related tribes (Powell et al., 2009).

There is also evidence gathered by anthropologists living in the field with nomadic foragers that they can occasionally join forces when drastic environmental changes such as a prolonged drought threaten their survival. The anthropologist Polly Weissner was able to record these survival strategies first hand while living among the San people (the bushmen) in the Kalahari desert at a time when they were experiencing severe stress caused by a prolonged drought. To survive, these nomadic foragers made use of an elaborate system of gift giving that the bushmen call hxaro (Weissner, 1982). Weissner spent two years tracking the extensive hxaro networks and found that adults had an average of 16 stable partners with whom they exchanged gifts in their band and with other bands. Interestingly, most of these partners are not close kin, but can be distant family members or “adopted kin”. This elaborate system of gift giving shifted into high gear during the drought, and significantly mitigated severe hunger and starvation among the bushmen. Weissner”s observations are regarded by many anthropologists as a likely scenario of how our human ancestors might have been able to cooperate and survive under similar conditions involving dramatic climate changes during the late Pleistocene (Balter, 2010).

Over the course of human history there are many examples of ethnic groups that have lived in peace with each other and have profited by their interaction, and we have learned over the centuries some of the conditions that make this conviviality between ethnic groups and nations possible (Bonta, 1997; Wiener & Slifka, 1998). It is not written in our genes that we are destined to live in destructive modes of competition and rivalry. We can mix civilized modes of competition with cooperative efforts, large and small. Our layered genetic and cultural evolution is a curse and a blessing, and each generation must meet the challenge of transforming our “genius for good and evil” (Fromm, 1964) by bringing out in Lincoln’s famous words “the better angels of our nature”.

The fate of dominance hierarchies: the ranking system in our species

For a good part of the prehistory of our species social hierarchies (the ranking system) were probably actively suppressed and controlled, but they were not eliminated. What happened to dominance hierarchies in our species? After the Neolithic revolution – the domestication of plants and animals and the invention of agriculture 12 thousand years ago – human settlements begin to appear in the archeological record, and as these settlements grew into large urban centers within the course of a few thousand years. With their growth, social hierarchies made a comeback, but this time transformed as hierarchical institutions. Once social functions could no longer be managed and regulated informally by small bands of nomadic hunter-gatherers, social hierarchies become a necessity in order to regulate and control these functions. Religious institutions emerged (in part) to create communities of like-minded individuals that share common beliefs and values and that can support and help each other (Wilson, 2002). Judicial institutions emerge to create and manage a body of laws that regulate civic duties and responsibilities. Policing institutions emerge to settle conflicts, and to keep antisocial individuals form having a free reign. Military institutions became necessary to defend from aggression from other groups or states and to wage war (Dubrueil, 2010). This history is very complex and egalitarian forms of organizations continued to coexist with these emerging institutional hierarchies. At times, the ruling elites of these social hierarchies take over these institutions and became despotic, but these despotic periods of our history have never managed to completely eradicate or squash our egalitarian longings rooted in the very origin of our species. 

This is not to say that institutional hierarchies are the only way social hierarchies have persisted among humans, and that ritualized dominance and submissive displays and behaviors, so dramatically displayed by our ape cousins, disappeared from the human condition, far from it. Bullies of all stripes are still with us, and the results of their bulling can have devastating consequences for their victims. The most productive way humans can channel our evolutionary legacy of dominance hierarchies and competition (the ranking system) is by instilling norms of fair play, and by creating a level playing field, where people compete based on merit and competence, rather than by the use of force and intimidation. Some of these competitive individuals can become leaders and might end up having a strong influence on people they lead. Our species has always been in need of good leaders that respect norms of human dignity and fairness, and have the required competence, vision and skills. Without these leaders social institutions cannot function well and humans cannot flourish (Maccoby, 1981, 2003).

We can also observe the fate of dominant submissive rituals and gestures (the ranking system) in clinical cases. Very little has been written about this application of evolutionary psychology to the field of mental health and psychopathology, but two pioneers stand out, the British psychiatrists John Price (1967) and Paul Gilbert (1989, 1992, 2005a, 2005b). It is beyond the scope of this essay to summarize their contributions, an effort that would require a long article by itself. Suffice it to say that Gilbert has developed a very interesting model of the mind model composed of four basic “social mentalities” that clearly overlaps with some our thinking. His model includes mentalities geared to seek protection, provide protection, cooperate and compete. We will add to this line of thinking by briefly exploring in the last two sections how the ranking system can be co-opted for defensive purpose to cope with complex, attachment-related trauma. 

Does humans relentless search for meaning spring from an existential awareness of our vulnerability and death?

Ernest Becker sustains that awareness of our finitude and death is the source of existential search for meaning (Becker, 1973). We think that this emergent phenomenon was the unexpected result of being a cultural animal in which high levels of consciousness become associated with symbolic thinking, autobiographic memory and language. Fromm this perspective awareness of our mortality can be understood as a spandrel (Gould & Lewontin, 1979). Spandrels are not the result of variation and selection (natural selection), but are emergent properties that come from the ensemble of biological or the social systems once they become sufficiently complex. Spandrels are therefore side effects of emergent complexity. It would take a convoluted logic to argue that awareness of our mortality served a useful evolutionary purpose. More likely awareness of our mortality was a fortuitous event that may have had the effect of creating a compelling need for explanations (belief systems) that give meaning to our existence and provide comfort and solace in order to cope with our awareness of death and vulnerability. These explanations can be religious or secular, but always involves the sharing of intersubjective and symbolic meaning-making processes.

We think that another example of a spandrel is the explosion of art during the Upper Paleolithic era (40,000 to 12,00 yeas ago) as can be fully appreciated in the caves in Altamira, Spain and in the caves of Lascaux and Chauvet in southern France. We will never know what purpose or meaning these beautiful cave paintings and exquisitely carved figurines found in these caves might have served, but it is not farfetched to see them as expressions of a need to recreate through art the emerging existential awakening of our species.

A hierarchy of evolved motivational systems

Natural selection endowed reptiles, birds and mammals with different motivational systems capable of regulating behavior in the direction of adaptive goals. The goal of each system, and the basic neural network and behavioral patterns needed to achieve it has remained quite similar across the evolution of different species. Some of these systems concern the relations of the individual organism with the non-social environment, and are the most ancient (the reptilian brain), while others motivational systems are involved in different aspects of the relation with members of their species (conspecifics) and are the characteristic of mammalian evolution. Still other motivational systems developed among our hominin ancestors and took the prosocial motives already present in mammals, to a whole new level of caring for others and ability to cooperate and collaborate in small large and very large projects—the neo-mammalian brain.

The Reptilian Brain

The evolutionary oldest, non-social systems evolved among reptiles and regulate homeostatic functions, reproduction, territoriality, exploration of the environment, predation, and defense from predators and other environmental threats.

The mammalian brain

Dominance hierarchies exist in some species of reptiles and are prevalent in almost all mammals and birds. The two main functions of dominance hierarchies in many species of mammals is to establish preferential access to sexual partners and food based on rank and to avoid contests over rank from becoming lethal through ritualized dominance displays and submissive gestures. Ritualized displays very often settle ranking contests from becoming a fight to death. The next set of motivational social systems that appeared during the evolution of vertebrates is associated with species in which parental care (caregiving behaviors and attachment (careseeking behaviors) and emerged 66 million years ago following the massive extinction of dinosaurs (a few species of dinosaurs had began to exhibit maternal care before this massive extinction). Maternal care and attachment are, of course, frequent feature of mammals. As we just mentioned, these social instincts evolved via kin type selection that are selected based on degree of genetic relatedness.

The neo-mammalian brain

An altruistic cooperative motivational system directed at nonkin member (the cooperative social engagement system) may have emerged in a rudimentary form among the bonobos who can share food with strangers who engage socially with them (Tan & Hare, 2013), but it is among human that affiliative ties toward kin and nonkin members takes a giant step. This phase of human evolution involved the emergence of a moral order in which shared prosocial norms and values played a leading role (Boehm, 2012). The emergence of cooperative breeding and long lasting sexual ties might have prepared our hominin ancestors for this evolutionary innovation. But is seems very likely that the emergence off an ultracooperative mutual aid system goes went hand n hand with the development of intersubjective communication and the ability to understand the minds of others through empathic and intersubjective abilities. In turn these developments set the stage for the emergence of neomammalian language and a symbolic culture that allows cultural learning to be passed on from one generation to the next.

Table 1 offers a summary view of the main evolved systems that organize and motivate human behavior and basic mental life.

                                              /……………………………………../

                       Insert table 1 here   

                                              /……………………………………../

 Table 1summarizes schematically and illustrates in graphic form the hierarchical organization of the various motivational systems, with the evolutionary older ones at the bottom, and the more recently evolved ones at the higher levels of the hierarchy. This implication of considering the time trajectories in the evolution of the various systems was intuited by Hughlings Jackson during the first half of the Nineteen Century (Farina, Ceccarelli & XX, YYYY); Meares, (2012) and by Paul Maclean in his model of the triune brain (MacLean, 1985). According to Hughlings Jackson, the evolutionarily older systems when activated by proper environmental conditions tend to pre-empt the activation of the other systems. At the same time, the evolutionarily more recent systems acquire regulatory capacity over the activities of the older phylogenetic systems.

Clinical Implication

There are significant implications of this account of human evolution, and the hierarchical and multimotivational model of the human mind that is one of the main legacies of this evolutionary history. These implications apply to the social sciences in general, and even more broadly to our views of human nature, but we will limit our comments to applications to the clinical dialogue. We will approach this section by breaking down the discussion into two parts. First, some basic characteristic of hierarchical multimotivational model of the mind, and second, we will expand on these points in regard to clinical with patients with complex trauma were the hierarchical view of motivation becomes a very useful theoretical tool with clear clinical implications.

Basic characteristics of the hierarchical multimotivational model

1. Different motivational systems have specific triggers that activate and “deactivate” them (deactivation is better described as being in a stand-by or expectant mental state). Take the attachment system as an example. When we perceive a threat or are in a vulnerable state such as being ill, we may feel stressed, frightened or anxious, and these feelings will activate a search for physical and emotional proximity to an attachment figure. Once comforted by attachment figures, the attachment system goes back to its stand-by state. If an attachment figure is not available or there is a history of attachment related trauma, we may go into a fight/flight reaction – the activation of sympathic branch of the autonomic nervous system (ANS) – or to a more phylogenetically primitive “feigned death” freeze reaction –the activation of the demyelinated parasympathetic (vagus nerve) branch system of the ANS (Porges, 2011).

2. There is a constant shift between different motivational systems, so that at any given time one motivational system is in the foreground and another in the background and vice versa, background becomes foreground (ichtenberg, Lachmann, & Fosshage, 1992). Lets say that a child is in a playground with his parents and scrapes his knee. The child will go to his mother of father (activation of the attachment system), who will comfort him (activation of the caregiving system in the parent). After being soothed, the child will immediately go back to exploring the playground or playing with other children. The exploratory system will then be activated if the child is interested in the equipment that is in the playground, or the cooperative and social engagement system becomes active if the child is playing with other children.

3. The shifts between motivational systems are not just intrapersonal phenomena; they are also interpersonal in nature as we see in the playground example, where the activation of the attachment system in the child activates the caregiving system in the parent. In this case different motivational systems (attachment and caregiving) have reciprocal functions and are relational partners. Sometimes the same motivational systems are activated in social interactions, as when the children are playing together in a “tag” game in the playground. In this case the cooperative and social engagement system is activated among all the children that are playing together.

4. Motivational system sometimes can interact at the same hierarchical level or between different hierarchical levels. When children are playing together and learning from each other, their neomammalian brain are operating at the same level. But if these same children find they are in danger (for instance they see somebody badly hurt or shot) the neomammalian functions are temporarily suspended and they will activate the mammalian attachment system or the defense fight flight system. In general survival functions organized as attachment defensive or fight flight reactions, will immediately suspend higher functions of the neomammalian brain’s cooperative and social engagement system. Since this social engagement system coevolved with intersubjective communication, they are functionally and dynamically related.  It is not unusual to see that when the attachment system becomes highly activated, the intersubjective abilities to empathize with others or maintain a perspective on these social relations are put on hold. In extreme cases involving cumulative trauma, we can observe the collapse of these intersubjective abilities—described by Fonagy and his colleagues as mentalizing abilities (Fonagy, Gergely, Jurist, & Target, 2002) by Main as metacognitive abilities, and from a self psychology perspective are seen an empathic ability to sense into the minds of others (Lichtenberg, Lachmann, & Fosshage, 2002)

5. Normally there is a harmonious back and forth between these different motivational systems. Clinically we observe that this back and forth between motivational systems can be used defensively (coopted) to cope with emotional conflicts or trauma. An example from the attachment literature will illustrate this point. The Strange Situation (SS) is a 20 minute laboratory procedure aimed at examining the balance between attachment and exploration when the attachment system is activated by a stressful situation (Ainsworth, Blehar, Waters, & Wall, 1978). Twelve to 18 month-old infants and their attachment figure (lets say a mother) are brought to the laboratory. The infant is stressed be having the mother leave the room twice, once the infant is left with a stranger and second time the infant is left alone. Securely attached infants, like all infants, are very stressed by this procedure. Yet babies with a secure history use their mothers well when they return by going to them and seeking their comfort without any hesitation. In turn, these mothers are effective in comforting their infants. Once comforted these infants very quickly return to explore the attractive toys that are in the room. In contrast, infants with an insecure (avoidant) attachment history behave very differently. Having had the experience of being ignored or even rejected when distressed, in the SS these infants avoid paying attention to their mothers when they return, and instead play with the toys. In effect, they co-opt the exploratory motivation by playing with the toys in order to self-regulate their distress.

This general principle is not limited to the exploratory system and can involve other motivational systems, as can be observed commonly in peoples lives and in clinical situations. The sexual mating system can be coopted to avoid the dangers of intimate relations by having shallow relations with multiple partners. The caregiving system can be coopted to avoid exposing vulnerabilities by becoming a rescuer of other vulnerable people. Bowlby (1980, pp. 156-157) described this personality type as “compulsive caregivers”. The ranking system (dominance hierarchies) can be coopted to cope with disorganizing fear toward an attachment figure, as we will se shortly.

With this general orientation, we can enter in greater details a terms of some clinical implication of this hierarchical multimotivational model. 

An evolutionary approach to post-traumatic syndromes

In the face of threats to survival or to physical integrity, the defense system, which evolved among vertebrates, becomes active with the typical sequence of autonomic, emotional and behavioral responses (fight, flight and feigned death) – a sequence whose neurological underpinnings we now understand quite well thanks to Porges’ (2011) polyvagal theory. Fight and flight involve autonomic hyperarousal of the sympathic branch of the autonomic nervous system and mobilize the organism. Freezing (brief phase of alert immobility with heightened muscle tone) is a demobilizing reaction and usually occurs when the animal cannot fight or fell and is in a hopeless state captured well by the phrase “freeze when no other type of flight is possible” This response is governed by the dorsal (demyelinated) part of the vagal nucleus (parasympathetic arousal)[9]. Feigned death produces flaccid immobility due to sharp reduction of the muscle tone, and extreme autonomic hypoarousal (very low respiratory and heart rates, very low blood pressure, numbing of consciousness).

The relevance of the experience of feigned death for our understanding of posttraumatic syndromes lies in its power to explain a group of symptoms that include autonomic hypo-arousal and somatoform symptoms linked to it, numbing of consciousness and, most important for the psychotherapeutic dialogue, a deep feeling of helplessness and impotence (Schore, 2009). These feelings and their somatic concomitants linked to the conscious or unconscious priming of traumatic memories, are at least as important in defining trauma-related disorders, as are the symptoms of autonomic hyper-arousal (the sympathic branch of the autonomic nervous system) listed in the DSM-IV diagnostic picture of post-traumatic stress disorder (PTSD). Knowledge of the evolved response of feigned death and freezing provides clinicians a good understanding of the dynamics of the parasympathic (vagal) nervous system and helps clinicians avoid interpreting these vagal symptoms of severely traumatized patients as ego defenses. 

When an attachment figure that is responsive and available during or soon after a traumatic event, the fight/flight response is inhibited by the parasympathic ventral (myelinated) part of the vagus nerve that supports cooperative and social engagement system and allows the child or adult to seek physical or emotional proximity. In other words after the traumatic event, a history of a secure attachment, mediated by good vagal parasympathic tone that supports the social engagement, acts as a protective factor that will inhibit the activity of the defense fight/flight sympathic mobilizing defense of the more primitive demobilizing freeze response mediated by the dorsal branch of parasympathetic system. Cantor (2005) has convincingly argued that all PTSD symptoms are the expressions of the protracted activation of the fight, flight, freeze defense system after the traumatic event is over (Cantor, 2005). The protracted activation of the defense system due to the unavailability of attachment figures in the aftermath of trauma (or to negative expectations associated with an insecure or disorganized attachment history) prevents making use of available help and soothing. There is evidence that such an ineffective operations of the attachment system and the protracted activation of the defense system, hinders the operations of the higher order cognitive functions involved in the activity of the intersubjective abilities (Liotti, 1999, 2004).

The relevance of considering the attachment system in the aftermaths of traumatic events is supported by research studies that suggest that the availability of attachment figures are carried forward as a set of positive expectations that others will be responsive and helpful are protective factors against the development of PTSD (XXXX, YYYY, ZZZZ). (Rauch et al., 1996 ).

These considerations merely summarize what we know of the interactions between the attachment and defense systems. A particularly interesting subtype of attachment insecurity, attachment disorganization, allows for further reflections on the psychopathological consequences of dysfunctional relations between defense and attachment.

Disorganization of attachment and complex PTSD

Infant attachment disorganization is observed in two main types of interaction with the caregivers: when the caregivers are straightforwardly hostile (Lyons-Ruth, Yellin, Melnick, & Atwood, 2005) and frightening to the baby (Main & Hesse, 1990), and when they abdicate their caregiving responsibilities (Solomon & George, 2011) because they feel helpless (Lyons-Ruth & Jacobvitz, 1999) or frightened by unresolved traumatic memories (Main & Hesse, 1990). 

While providing care, some attachment figures become abruptly aggressive and frightening to the infant. This puts infants into an irresolvable conflict, since attachment figures are also havens of safety. These caregivers become at the same time the source of the infant’s fear and the solution of the infant’s fear (Main & Hesse, 1990). In these circumstances, the attachment and the defense systems are activated simultaneously, causing a state of fright without solution (Main & Hesse, 1990). The result is an escalation of fright combined with utter helplessness. The conflicting activation of the defense and the attachment system in the infant can also be caused by caregivers who are not aggressive or maltreating, but who are unable or unwilling to respond the infant’s cry for help and soothing. This possibility is dramatically illustrated by the still face experiment (Tronick, 2007) where babies in the first months of their life respond, in the span of a few seconds, with fear, and then with unmistakable signs of feigned death. The latter reaction is indicative of dorsal demyelinated vagal activation (Shore, 2003) to the caregivers’ lack of responsiveness to infants cues and communications. The evolutionary theory of motivational systems explains this phenomenon by recognizing that the functional links between attachment and defense from danger are wired in the architecture of motivational systems as it evolves in mammals and especially in primate species. The experience of lack of caregivers’ response to bids for help and soothing activates by default the defense system in the infant, even in the absence of immediate environmental threat. Since human infant’s extreme motor immaturity prevent fight or flight when facing threats, it is not surprising that the activation of the freeze response (analogous to feigned death) is the only remaining strategy. This response can also be seen or in the still face experiment (Tronick, Als, Adamson, Wise, & Brazelton, 1978).

Signs of the activation of the defense system are evident in babies with disorganized early attachment – either due to caregivers’ frightened/helpless/abdicating attitudes or to caregivers’ hostility and explicit violence during the Strange Situation (SS) (Main & Solomon, 1986). The infant’s disorganized attachment behavior in the SS is characterized by one or more of the following: freezing in the middle of an attempted approach to the caregiver, fright-avoidance, rage and attempted attacks to the caregiver, collapsing to the ground and stilling – caused by dorsal vagal parasympathic arousal (Porges 2011) – or by abnormally exhibiting slow movements (as if the baby was moving in water).

The knowledge of attachment disorganization provides a relational context for understanding the core dissociative of disorders related to personality development that have their roots in traumatic or neglecting family environments. Herman (1992) and Gunderson and Sabo (1993) among others, suggest that these disorders should be regarded as instances of complex PTSD that may become expressed as borderline personality disorder (Meares, 2012) or as dissociative disorders (Liotti, 2004, 2006). The role played by the defense and attachment system in the genesis of attachment disorganization and pathological responses to trauma suggest that dissociation is not merely an inner defense from mental pain, it also includes a specific form of relatedness (Lyons-Ruth, 2003; Meares, 2012). Controlled longitudinal studies show that this type of relatedness originating from an early attachment disorganization predicts later dissociation more than does exposure to traumatic events (Dutra, Bianchi, Siegel, & Lyons-Ruth, 2009; Ogawa, Sroufe, Weinfield, Carlson, & Egeland, 1997).

The cooption of the ranking system in patients with histories of disorganized attachment and trauma  

Dissociative symptoms and behavioral disorganization have not been observed clinically in the interactive behavior of school age children who have a history of disorganized attachment. This is probably explained by the discovery made in two samples in a low risk prospective longitudinal studies. By the age of six, these children develop strategies aimed at controlling their caregivers’ behavior either through dominant-punitive or through protective-caregiving attitudes (Main & Cassidy, 1988; Watner, Grossmann, Gremmer-Bombik, & Sues, 1944). The protective-caregiving response of children is an indication of an inversion of the normal direction of attachment-caregiving interactions between parent and child (Bureau, Easterbrooks, & Lyons-Ruth, 2009). The evolutionary model that we present explains the development of these controlling strategies with the hypothesis that in order to avoid shattering dissociative feelings, unbearable experience of fright without solution, and the helpless relational chaos, the ranking and the caregiving systems, are coopted for defensive purposes (Liotti, 2011). The cooption of the ranking system leads to the dominant punitive controlling pattern, while the cooption of the caregiving system leads to the protective caregiving pattern.

The relational problems that emerge to try to regulate the dissociative experiences and controlling strategies linked to a history of disorganized attachment, and the incoherent representational models of attachment create formidable challenges during the clinical exchange. It is not unusual to observe during a therapeutic process that is progressing well the sudden emergence of dominant-punitive attitudes and behaviors. These sudden disruptions are difficult to understand on the basis of previous exchanges. The conflicting activation of the defense and the attachment system together with the activation of controlling strategies lies at the root of many traumatic transferences and countertransferences (Howell, 2011). The hierarchical evolutionary model that we have outlined suggest that at the beginning of treatment these difficulties with complex trauma can best be dealt with by trying to maintain a dialogue that attempts to limit the activation of the attachment system by taking advantage of the natural tendency to want to cooperate and collaborate on an equal basis levels. This natural tendency is the legacy of our species ultracooperative path toward survival. Optimally, we try to develop a secure base and a haven of safety in therapy in order to facilitate the exploration of the relational dilemmas and severe conflict brought by complex trauma and disorganized attachment. Often, this goal has to be reached through a circuitous route that tries to limit the premature activation of the attachment toward the therapist. Otherwise the transferential activation of the trauma early in therapy will create a state of panic and can triggers the fight, flight or freeze responses as well as controlling strategies that are very hard to contain and almost impossible understand.

Hoe the cooperative and social engagement systems helps in restoring the therapeutic alliance

The highly developed cooperative/altruistic system in humans (the cooperative and social engagement system) that coevolved with intersubjective abilities is instrumental in building mutuality, trust and hope, key ingredients of the therapeutic (working) alliance and being able to repair the inevitable disruptions that will occur in therapy. The establishment of a working alliance builds on mutuality, and provides the necessary scaffolding that will allow patients with histories of traumatic attachment to build trust before they are able to expose deep wounds. Mutuality and trust are the sine qua non in the treatment of patients with histories of cumulative childhood trauma and disorganized attachment (Van der Hart, Nijenhuis, & Steele, 2006). The model of a hierarchy of evolved motivational systems helps explains the key role cooperation and intersubjective communication plays in developing of the working alliance based on mutuality. A working alliance based on collaboration and mutuality, together with an empathic engagement geared to sense into the intentions feelings and mental states of patients, allows for a gradual modulation and mentalization of unbearable mental states linked to disorganized attachment and fight/flight/freezing defensive operations.

Shared goals during the therapeutic dialogue, shared attention and shared intentionality are hallmarks of the activation of the cooperative and social engagement system (Tomasello et al., 2005). By building on the foundation of shared goals within a spirit of inquiry and mutuality, we give patients time to express attachment longings toward the therapist. Building a cooperative foundation during clinical dialogue preserves mentalization – otherwise severely hindered by the activity of the disorganized internal representations of attachment, and helps limit panicked fight flight reactions. Minimizing these disruptive episodes in the therapeutic keep mentalization from becoming severely compromised by dysfunctional recruitment of the ranking system (controlling punitive strategies) or by the recruitment of the caregiving system (compulsive caregiving strategies). As disruptions become less frequent and repairs to the therapeutic alliance develop, it gives time for patients to gradually regain these vitally important perspective-taking (mentalizing or empathic) abilities.

As we mentioned earlier, other forms of defensive cooption might be recruited (coopted). For instance, the sexual system might sexualize the therapy relationship and thus protecting form true intimacy and exposing vulnerabilities. The stable activation of the cooperative and social engagement system during the clinical exchange allows therapists to explore the role and the meaning of the controlling strategies as ways for protecting the sense of self from shattering relationship experiences linked to the activation of unconscious traumatic memories. A cooperative approach that has built trust over time also helps when controlling strategies are enacted in therapy.

During the first phases of the treatment it is common that patient and analyst may feel deeply powerless in dealing with highly distressing depersonalization symptoms and ongoing trauma-related dissociative experiences that interfere with mentalization (Liotti, in press). If the analyst consciously accepts and contains the feeling that the usual analytic tools, sympathy included, cannot help these deeply suffering patients, the evolutionary model we have proposed opens the possibility that the a particular type of intersubjective communication can begin to regulate the clinical exchange. The analyst fervent desire to persevere in the work in the face of many challenges is tacitly shared through the intersubjective nature of human communication. The mirror neuron system may mediate this seemingly paradoxical type of intersubjective sharing, even when it is never expressed in words by therapist or patient (Liotti, in press). We think that this is because intersubjective communication is linked to the cooperative and social engagement system, operate at a higher level of the motivational hierarchy (the neomammalian brain), while the defense system activated of memories of disorganized attachment operate at lower mammalian and reptilian levels brain. The intersubjective communication of hope and perseverance may set in motion important corrective relational experiences by offsetting symptoms of depersonalization and feelings of powerlessness linked to childhood traumatic memories. By staying with the patient during these episodes powerlessness with attentive forbearance, the analyst is communicates that the traumatizing experiences of neglect and isolation with attachment figures will not be repeated. It is important to emphasize what the analyst is not doing. The analyst is not minimizing the impact of the trauma, as perhaps attachment figures may have done in the past (which is a denial of the child’s suffering and severe empathic failure). Isolation and mistrust gradually fades away as the persistent activation of the defense system, experienced as deep powerlessness and depersonalization diminishes. As a consequence depersonalization symptoms may slowly subside and the mentalization capacities improve (Liotti, in press).

Conclusion

We want to conclude this essay by sharing with our readers a few reflections. The model we have presented is based on the work of many scientists and researchers who are challenging traditional views on the evolution of altruism and cooperation that have dominated the field in the past few decades. These view sees genes as selfish replicators that are pursuing their survival through cooperative means, and see cooperation as a type of mutualism, such in Tit for Tat games based on the principle that says “I will cooperate with you to the extent that you reciprocate in kind, otherwise I will defect”. The problem with these views is not that they are wrong; it is that they are partial, and only capture part of the remarkable story of human evolution. The emergence of prosocial motivations and emotions that are genuinely altruistic, and take pleasure and satisfaction in helping others is the other side of the story. This other side needs to be told. Otherwise we are left with skeptics that believe that any collective efforts to make progress on the huge challenges that face humankind are naïve and ignore human nature. These same skeptics believe that the problems will take care of them selves if competitive forces (markets) are left alone to do their work and enlightened self-interest prevails (the invisible hand). What this blind faith in individualism ignores is that markets and the invisible hand can only succeed when there is a foundation of shared prosocial values and motivations, and institutions that support fair play and regulate these markets. We have seen what unbridled markets can do to nations and to the global economy.

Yes we are an ultracooperative species, but we are also a deeply ambivalent species. Selfish motives compete with genuinely altruistic motives, domination and control compete with a thirst for equality and fairness, a sense of solidarity toward people who are like “us” can easily turn ugly against people we see as different, as “them”. The view that emerges from this evolutionary story is not all sweetness and light, but it does affirm that altruism, empathy, and fairness are built into the fabric of our species.

First and foremost we are psychiatrists and psychotherapists that try to help people in trouble and make a difference in their lives. We believe this evolutionary story we have outlined and the multimotivational and hierarchical model that underpins it can be of great clinical value. Multimotivational models have not have not received the attention they deserve in psychoanalysis and the psychotherapy field in general, and we hope this essay and evolutionary version of a multimotivational model we have outlined will contribute toward their dissemination. 

TABLE 1

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  [1] Our human ancestors lived as nomadic hunter-gatherers until very recently, when the first human settlements begin to appear 12,000 years ago. An egalitarian social organization of nomadic hunter-gatherers probably appeared sometime during the Pleistocene. The Pleistocene is defined by periodic glaciations that begin roughly 2.2 million years ago and end with the Holocene to 12,000 years ago. The emergence of an egalitarian ethos laid the ground for the emergence of cultural modernity that included a complex tool kit, symbolic representations, art and language. Cultural modernity appears during the late Pleistocene (120,000 to 12,000 BP), first in a more rudimentary form in Southern Africa 77,000 BP (Balter, 2011b) and later as a “full package” in Europe 42,000 BP (Maccoby, 1981). 

[2] To simplify, most evolutionary models assume equivalence between an allele (altruistic or selfish) and a corresponding behavioral trait. This deterministic view is, of course, incorrect any phenotypic expression of genes, such as a complex altruistic trait, requires the coordination of many genes that are turned off and on during development by epigenetic mechanisms. The simplistic model serves as an approximation and can be made more complex yet arrive at a similar conclusion. But sometimes this seemingly benign assumption can be very misleading and obscure possibilities for altruistic expression (see Sober and Wilson, 1998, pp. 105-106). 

[3] There are many sources of evidence demonstrating the ultracooperative nature of our species, such as experiments conducted by behavioral economists using social games that present people with social dilemmas (game theory) such as the ultimatum game, the prisoner’s dilemma and social goods games. These social dilemmas pit cooperation and altruism against self interest and show just how widespread norms of fairness and altruistic cooperation prevail in many societies and cultural groups around the world (for a summary see Bowles & Gintis, 2011, pp. 19 -20; Henrich et al., 2005). Other source of evidence are studies comparing between African apes and humans in terms of cooperation and competition under various experimental conditions (for a summary of these studies see Tomasello, 2009). It is only when converging evidence coming from multiple sources begin to support a particular hypothesis that we can have confidence that we are on the right track. We think this converging evidence overwhelmingly points toward the ultracooperative nature of our species.

[4] World Bank. Report on Gender, Equality and Development (2012).

[5] A recent article on bonobos is beginning to modify our view of the social life of African apes, by showing that bonobos will share food with strangers as long as the are engaged socially with them (Tan & Hare, 2013). 

[6] Fromm, E (1936) Studien über Autoritat und Familie In Socialpsychologischer Teil, GA III 139-137.

[7] The “full package” showing the emergence of cultural and behavioral modernity consists in the presence of symbolic expressions such as abstract and realistic art, body decorations (threaded shell beads, teeth, ivory, ostrich shells, ochre, tattoo kits), systematically produced microlithic stone tools such as blades and burins, as well as grinding and pounding stone tools, functional and ritual bone, antler and ivory artifacts, evidence of improved hunting and trapping technology such as spear throwers, bows, boomerangs and nets, and last, but not least, the appearance of musical instruments in the form of bone pipes. The full package would have required that our nomadic ancestors were able to transfer raw materials over long distances (Powell et al., 2009). The first evidence for cultural modernity in a less developed form appear in the tip of South Africa 77,000 BP (Balter, 2011a), and later in Europe as full package 42,000 BP (Balter, 2012a).

[8] (for reviews of the all forms of selection including kin selection, direct and indirect forms of selection and multilevel models see Bowles & Gintis, 2011; Henrich & Henrich, 2007; Leimar & Hammerstein, 2001; Nowak, 2006; Nowak & Highfield, 2011).

[9] The survival value of feigned death lies in the fact that predators often avoid eating an animal that looks dead.