What is the systematic study of the biological basis of social behavior called?

Conclusion

The widespread and successful use of ART directed at HIV-1 has continued to develop rapidly (seeChapter 128). Significant advances in the ability to treat individual cases, propelled by an understanding of the biology of the virus, have led to the control of viral replication and have altered the course of disease progression. At present, patients have been maintained on combination therapy for years, with a low rate of relapse because of the development of resistance and low viral burdens. Immune restoration and long-term biologic control or complete eradication of the virus with minimal toxicity remain elusive goals, but intense efforts continue to focus on new anti-HIV therapies. As we have learned, retroviral disease has important social aspects that, as much as viral biology, determine the extent of viral transmission and the dimensions of the epidemic; this results in a series of epidemics, each with a unique sociobiology. Moreover, despite remarkable progress, social and economic effects of the global HIV epidemic have materialized vividly in sub-Saharan Africa, with devastating losses of population life expectancy and productivity. Renewed emphasis on the development of an effective anti-HIV vaccine that might stem an ongoing epidemic or ameliorate the course of disease has been the subject of intensive study in nonhuman primates and in clinical trials (seeChapter 119). The history of retrovirology has been filled with remarkable, often serendipitous, discoveries based on scientific imagination supported by technologic advances. There is every reason to expect that continued advances will deepen our understanding of fundamental biologic processes and that we will meet the challenges presented by HIV and the inevitability of the emergence of new pathogens.

Abstract

Sociobiology is an evolutionary science concerned with all patterns of social living, including those of humans. Established by Edward O. Wilson's famous 1975 book Sociobiology: The New Synthesis, sociobiology is distinguished from the more familiar fields of ethology and evolutionary psychology (which stress individual behavior) by its focus on the organization of entire social populations. Sociobiology explores the hypothesis that such whole-society traits are in part emergent, adaptive outcomes of Darwinian evolution. While gene selection illuminates much animal behavior, human sociality depends crucially on the cycle of gene–culture coevolution. In both animal and human evolution, creativity and innovation behavior may take prominent roles, with surprising outcomes. Wilson thought that it was just a matter of time before sociology (the science of human social behavior) incorporated sociobiology. Until recently, however, sociology and sociologists largely rejected sociobiology. There is now more acceptance of sociobiology within sociology, although it remains highly controversial within the field.

4 Sociobiology and the Emotions

Sociobiology brought a new perspective to bear on the evolution of emotion in the 1970s and 1980s. It also moved the focus of investigation from the basic emotions to the moral and quasi-moral emotions involved in human social interaction. Emotions such as trust, loyalty, guilt, and shame play an obvious role in mediating the competitive social interactions that were the focus of most research in human sociobiology. Numerous sociobiologists made brief comments to the effect that moral emotions must have evolved as psychological mechanisms to implement evolutionary stable strategies of social interaction (Weinrich 1980). Robert A. Frank suggested that the moral emotions evolved as solutions to ‘commitment problems’ (Frank 1988). A commitment problem arises when the winning strategy in an evolutionary interaction involves making a binding but conditional commitment to do something that would be against one's own interests if the condition were ever met. If such a commitment is to be credible, some special mechanism is needed which would cause the organism to act against its own interests. Frank suggests that emotions such as rage and vengefulness evolved to allow organisms to engage in credible deterrence, threatening self-destructive aggression to deter a more powerful aggressor. Conversely, emotions such as love and guilt evolved to allow organisms to engage in reciprocal altruism in situations where no retaliation is possible if one partner fails to reciprocate.

Sociobiologists criticized ethology for its lack of a theoretical framework with which to predict how humans would behave, accusing it of being little more than descriptive natural history (Barash 1979, Barkow 1979). In contrast, sociobiology seemed to make strong predictions that clashed with some aspects of the affect program theory of basic emotions. From a sociobiological perspective it makes no sense for organisms to possess involuntary expressive behavior. The application of evolutionary game theory to emotional behavior predicts that this behavior will be designed to manipulate the expectations of other organisms rather than to ‘express’ emotional states transparently. This theoretical argument has been used by some to reject the affect program view of basic emotions. Alan Fridlund has argued that emotional behavior should be regarded as a paralanguage of social signals whose production depends at least as much on an organism's social context as on its emotional state (Fridlund 1994). Fridlund and other paralanguage theorists have documented audience effects on the production of the basic emotions and have argued that this is inconsistent with the affect program theory. They have also tried to show that the classic facial expressions of emotion are not strongly correlated with underlying emotional state and that people rely more on context than on behavior in attributing emotions to others (Russell and Fernández-Dols 1997). It is unclear, however, that this data contradicts the predictions of the affect program theory. Signaling behavior exhibits audience effects in many organisms, such as domestic chickens, in which that behavior is presumably part of a highly stereotyped behavior sequence controlled by a relatively simple cognitive mechanism.

Mark Hauser has suggested that Fridlund's arguments bear on questions about the biological function of emotional behavior whilst the affect program model is concerned with the mechanisms that produce that behavior (Hauser 1996, pp. 495–6). In some places, however, Fridlund does seem to be discussing the nature of the underlying emotional processes and not merely their biological function. He argues that since emotions are signals and are produced because of the impact they will have on other organisms, a particular emotion defined behaviorally need not correspond to any particular motivational state (emotion) of the organism producing it.

‘Sociobiology’ is the study of social phenomena within the conceptual framework of evolutionary biology. Its hallmark is viewing social phenomena as products of the Darwinian processes of natural and sexual selection. Sociobiologists use theories from population biology, genetics, and ecology to predict and explain the evolution of social behavior and its diversity, within and between species, following the same ‘adaptationist,’ ‘selectionist’ logic that biologists use to understand the evolution and diversity of anatomy and physiology. ‘Adaptationist’ means that sociobiologists usually assume that complex social phenomena such as mating preferences, offspring sex ratios, discriminative treatment of young by parents, etc., have a functional significance for the behaving animal that can be illuminated by appropriate hypothesis testing. ‘Selectionist’ means that sociobiological hypotheses usually entail the assumption that social attributes have been shaped by a history of selection to be effectively fitness promoting in ancestral environments. Although Darwin's nineteenth century contributions laid its foundations, sociobiology matured only in the 1960s, under the influence of Hamilton's inclusive fitness theory and Williams's defense of the proposition that the differential reproductive success of individuals, not groups, is the level of selection that is most effective in creating adaptations. The approach, also called ‘behavioral ecology,’ now dominates animal behavior research.

What Are Behavioral Ecology and Sociobiology?

Behavioral ecology and sociobiology are terms that designate an approach to the study of behavior in which inquiry typically focuses on how behavior has evolved by natural selection, especially how behavioral differences among species have arisen in relation to their natural environments. As sociobiology, which is limited to social behavior, is essentially included within the term behavioral ecology, custom has come to favor use of the more inclusive term behavioral ecology. The dominant integrative theme of behavioral ecology, namely the role of natural selection, is unfortunately not explicit in either of these terms. Nevertheless, both involve the close integration of ideas from ecology, evolution, and ethology.

The Emergence of Sociobiology

The Darwinian Turn

Evolutionary theory offers to tell us the story of the origins and development of human nature. Many contemporary philosophers and scientists believe that the basic story told by Darwin and his successors is the only serious explanatory paradigm available today. This turn of events and theories is of the utmost significance for a view of human nature because Darwin’s theory challenges traditional assumptions about human nature – for example, that it is static and unchanging, and that it is wholly and essentially different from nonhuman nature. In addition, evolutionary theory itself has become part of the story of humanity.

Darwin began with a general explanation of the origin of species through natural selection and later applied his view to human beings and human nature. Unlike those who inferred a particular nature from race, ethnicity, or physical appearance, Darwin’s view was that biological variation within and between species is the product of successful adaptation to environment over time, under conditions of scarcity and competition. Given the heritability of biological traits, those traits favorable to survival and especially to surviving long enough to reproduce will themselves survive over time; others will disappear. Evolution through natural selection, then, is not a purposive or teleological process, nor do adaptation and survival carry any positive normative connotations. Certain changes, including mutations, are advantageous to survival. Those individuals and species that do survive are neither morally better nor morally worse than those that perish or become extinct; they are simply nature’s survivors.

Darwin’s view of human nature is decidedly naturalistic. We can follow our species’ evolutionary path, tracing change through adaptation. Vital in our success, he thought, is our capacity for rational thought. Unlike Aristotle’s view, however, Darwin saw this capacity not as the preexisting, unchanging, unique marker of human nature but instead as itself a product of natural selection. Those able to make the best use of changes in neurological structure and function in our evolutionary past were more likely to survive and reproduce, and thus to pass along the capacity for reasoning. In the largest sense, the Darwinian story of the evolution of human nature is the following: think or die (out).

Although Darwin did not introduce normative baggage into his view, those who followed him did. Social Darwinism adapted evolutionary theory to the service of eugenics. One of its champions was Darwin’s cousin, Francis Galton, who introduced the term ‘eugenics’ in an 1883 collection of essays that summarized his attempt to explain human faculties by means of hereditary influences. In those essays, Galton claimed that in the evolution of humans, some negative elements exist due either to residual, ancestral traits or to degeneration of positive characteristics. It is the elimination of those negative elements that Galton and the social Darwinists sought.

Claiming that evolutionary success was evidence of moral fitness, and that both could be read from social, educational, or economic success or from membership in certain ethnic or racial groups, social Darwinists developed a type of biodeterminism that attempted to explain psychological and moral superiority in evolutionary terms. From these explanations and models arose plans for social action for improving the human stock.

Psychologists and anthropologists joined some biologists and (later) geneticists in developing strongly deterministic, evolutionary models of human nature. In the late twentieth century, sociobiology emerged as yet another sophisticated biodeterministic view of human nature. Harvard entomologist E. O. Wilson and his sociobiologist colleagues described human nature and culture as the product of genetic evolution. Only relatively recently in evolutionary history, according to Wilson, and only to a limited degree have social and cultural factors played a role in shaping human nature.

In his accounts of sociobiology, Wilson has attempted to describe genetically linked traits of human nature without defending all of the more negative aspects of biodeterministic theories. Unlike Wilson, however, some twentieth-century and contemporary thinkers have not hesitated to use analogies and inferences from evolutionary biology and contemporary genetics to defend the normative elements of earlier views, including the following claims:

There is a single, inherited type of intelligence factor, often referred to as general intelligence factor or ‘g.’

Differences in intelligence test scores demonstrate that there is an inherent racial difference in intelligence levels, and that African Americans (and, it is sometimes claimed, other racial groups) are naturally inferior in intelligence to whites and other groups.

Aggression – especially male aggression and dominance – is natural in humans; sometimes this is extended to the claim that warfare is natural and virtually inevitable.

Criminality and social deviance of several varieties are biodetermined.

Thus, it is not just nineteenth-century social thinkers but also twenty-first-century natural and social scientists who continue to advance biodeterministic views of human nature. Books and essays published in 2008 and 2009 claim new ground for the field of ‘biocriminology,’ whereas studies published in the first decade of the twenty-first century use advances in neural mapping to support claims that general intelligence is traceable to a specific frontal system in the brain; still other studies of the human genome identify specific chromosomal regions linked to intelligence. Although these developments are more subtle and sophisticated than their nineteenth-century antecedents, rarely if ever making the sweeping claims of racial or ethnic superiority, the theoretical adequacy of the arguments and the potential practical implications of the conclusions have generated vigorous debate.

3 Testing Sociobiological Hypotheses

One central problem for sociobiology is to move beyond plausibility stories to develop clear empirical tests of specific sociobiological hypotheses. It is not obvious that this problem can be solved at all. The resources of comparative biology offer one of the most powerful methods of testing adaptationist hypotheses (Harvey and Pagel 1991). For example, suppose we suspect that a certain leaf shape is an adaptation to arid conditions. If we show that within a particular tree family (e.g., the eucalypts) that there is a strong covariation between long, narrow, waxy leaves and distribution through an arid habitat, we could reasonably regard that hypothesis as well confirmed. It would be confirmed especially well if the ancestor of our (putative) arid-adapted trees did not have long and narrow leaves, for we could then rule out the hypothesis that the leaf shape was no more than an inheritance from a common ancestor. If we found the same pattern in other tree species, our confidence in our adaptive hypothesis would be stronger still. Unfortunately, we cannot apply the methods of comparative biology to test the most interesting adaptive hypotheses about human psychological mechanisms. Our closest relatives are extinct. So many of these mechanisms are found only in our own species. Even where they are shared with our closest living relatives (e.g., the facial expression of emotion) they exist in a different form. Moreover, the human lineage—and even the human and great ape lineage combined—is not bushy; the eucalypt, in contrast, boasts hundreds of species. The comparative method can tell us nothing at all about the adaptive significance of language and very little about tool making, true imitation, and many other important human cognitive adaptations.

The main alternative to comparative biology is the development of quantitative evolutionary models. If there is a good quantitative fit between model and data, we can regard the model as passing an important test (Orzack and Sober 1994, Orzack and Sober 1996). But here too the prospects are dim. First, it is often hard to actually measure the impact of behavior on human fitness. Economic resources typically are used as a measure of fitness benefits. But even in hunter–gatherer societies this is probably too crude. For fitness probably does not vary as a linear function of economic resources. Second, in developing an evolutionary model, we need to define a space of possibilities. For the adaptationist hypothesis is that the fittest behavior within that space will become established by selection in the population. Yet how do we develop a possibility space for human behavior? To recycle on example from Kitcher, what were the realistic alternatives of, say, a man in an avunculate society? Could he defect from the avunculate, directing his resources to his wife's children, rather than to his nieces and nephews (Alexander 1979, Kitcher 1985)? Finally, and most importantly, we face the problem that humans now act in a very different world from that in which human psychological mechanisms evolved. So measuring the impact of behavior on current fitness seems beside the point. Yet, of course, we have no access to the fitness consequences of behaviors in those ancestral environments.

So the problem of testing sociobiological hypotheses is very serious. The shift in theoretical interest from behavior to the mechanism that produces that behavior in one way makes the problem even more intractable. The Wilson program took the unit of adaptationist analysis to be a behavioral pattern. Such patterns are observable, though if they are patterns in sexual behavior, violence to outsiders, or infanticide, they will not be easy to observe. The program of evolutionary psychology adds to the existing methodological problems yet another: inferring cognitive mechanism from behavior. This is known to be difficult. But in one important respect, evolutionary psychology improves the prospects for testing sociobiological hypotheses. To the extent that evolutionary psychology makes specific architectural claims about human cognition, these are subject to direct empirical test. For example, Frank has argued that emotions function as commitment devices; they bind agents to future courses of action that will not then be in the agent's interest, and thus tend to maximise the agent's overall long run welfare (Frank 1988). It is a consequence of this theory both that emotions are not under central control, and that other agents are good at using emotional signals to predict future behavior in commitment situations. These consequences are directly testable by experimental psychology.

However, a positive test does not directly vindicate the adaptive hypothesis that is alleged to explain the existence of the proximate mechanism. Moreover, the relationship between adaptive function and proximate mechanism is often less direct than this example suggests. Sober and Wilson point out this in their discussion of altruism. They argue that there are good reasons to believe that humans are a group-selected species, and hence that human behavior will often be altruistic in the evolutionary sense. Its function will often be to promote the fitness of the group at some cost to the agent's fitness. But Sober and Wilson point out that while this constrains the proximate mechanism, it does not fix it. Altruistic agents might act altruistically because of irreducibly altruistic motivations, or because selection has built in internal rewards. Altruistic behavior could be engineered either way (Sober and Wilson 1998). In short, then, despite the shift from adaptive theories of behavior to adaptive theories of psychological mechanism, the problem of the testability of sociobiology remains very serious.

4 Concluding Remarks

When in the mid-1970s sociobiology made the headlines and behavioral ecology started riding the new wave of environmental awareness, the glamor of ethology began to fade. In 1999, the crown jewel of ethology, the Max Planck Institute for Behavioral Physiology at Seewiesen, was downgraded to an ornithological research station. However, the ideas conceived and publicized by Lorenz, Tinbergen, and their contemporaries as the foundations of ethology have become so much public property that their original sources are now rarely cited. This may be the best indicator of the importance of the work of Konrad Lorenz, and of ethology.

Introduction

One of the fathers of modern sociobiology, E.O. Wilson, defined a society as ‘a group of individuals belonging to the same species and organized in a cooperative manner.’ By this definition, all societies consist of aggregations of individuals, but not all aggregations are societies. Male mosquitoes, for instance, may form swarms but they lack the requisite level of cooperation to be considered social. Bird flocks and wolf packs, on the other hand, are generally considered societies because their members not only form groups, but also cooperate – for example, through alerting one another to the presence of predators, or through hunting in packs. Sometimes, the cooperative acts within societies come at a significant cost to the cooperators themselves, and such behaviors are termed ‘altruistic.’ Worker honeybees, for example, forego their own reproduction to help their queen reproduce and will even die in her defense.

Potential benefits of social living include a reduction in the rate of predation, improved foraging efficiency, improved defense, and improved care of offspring. For example, due to increased vigilance, the success rate of goshawk attacks on pigeons tends to decrease with increasing numbers of pigeons in a flock. Likewise by huddling together, emperor penguins help save energy and maintain a constant body temperature, thereby ensuring the successful incubation of their eggs. While it is often easy to see the benefits of group living, it is harder to understand why individuals do not free-ride on those benefits while giving nothing in return. Therefore, to understand how societies function and persist, we must understand the stability of the cooperative relationships that help define them. In his last presidential address to the Royal Society of London in November 2005, Robert May argued: ‘The most important unanswered question in evolutionary biology, and more generally in the social sciences, is how cooperative behavior evolved and can be maintained.’ Here, we review some of the principal solutions to understanding the evolution of cooperation – and hence societies – that have emerged over the past 50 years. Many of the solutions we discuss have also been applied to understanding the origin and stability of other forms of cooperation – including cooperation between cells in multicellular organisms and examples of cooperation between members of different species.