Sociobiology

views updated Jun 08 2018

Sociobiology


In the Origin of Species (1859), Charles Darwin argued that the main mechanism of evolutionary change is a process he called natural selection. More organisms are born than can survive and reproduce, bringing on a struggle for existence. Given naturally occurring variation, there will be a differential reproductionsome reproduce, some do notakin to the artificial selection practiced by animal and plant breeders, with the end result of permanent change. In a drought, animals able to do with less water are "fitter" than those that need to drink more. Moreover, organisms will be adapted: they will show the organic contrivances highlighted by those natural theologians intent on showing that there is a designing God. Examples include the hand and the eye and such like. Darwin applied this mechanism to many different fields of biology, including paleontology, embryology, systematics, and biogeography. Behavior was included in Darwin's theory, for he saw that what an organism does is as crucial in the struggle for existence as what an organism is. There is little point in having the physique of Tarzan if you have the mind of a monk.


The evolution of sociobiology

Darwin was particularly fascinated by certain social behavior, especially that of ants, bees, and wasps (hymenoptera), where an organism sacrifices itself for the good of the group. It seems prima facie that such behavior is at odds with the kinds of self-centered acts that would lead to individual success in the struggle for existence. Darwin understood how the sterility of a worker ant, for example, might be transmitted through fertile nest membersthe domestic world had shown how one can select vicariously, as it were, for characteristics in animals that will not themselves breedbut he could not see how sterility itself would come into being. Darwin was convinced that all selection must be for the individual, not the group; socialityworker sterility, in particularwas a major challenge. Although Darwin concluded that one can regard the colony (of ants and so forth) as a kind of superorganism on which selection can operate as a whole, he never really resolved the problem of sociality.

For a number of reasons, the study of the evolution of social behavior lagged after Darwin. First, the rise of the social sciences with their interests in behavior discouraged biologists from addressing the subject. Social scientists tended to experiment on rats and mice, to generalize, and then to conclude that transpecific differences were irrelevant. Social scientists also tended to work in artificial situations and so were generally not interested in natural behavior, and unable to recognize it when it appeared. Second, in the first half of the twentieth century, the racial doctrines of the Third Reich convinced many that the study of social behavior from a biological perspective would lead to claims about the innate behaviors of humans, with consequent belittling of the worth of those not in one's own group. Although some protested that such fears should not tar all biological studies on behavior, the damage was done and remained for many years after the Second World War. Most importantly, no one really knew how to move theoretically beyond Darwin so that social scientists could study social behavior while staying true to the principles of natural selection. The social sciences needed new approaches that eschewed group selection, allowing evolutionists to dissect nature and drag forth its secrets.

Kin selection. Breakthroughs came in the 1960s. A number of models were devised that allowed scientists to study social behavior in animals, while staying true to the individualist or "selfish" nature of selection. Notable was the theory of kin selection, devised by the English biologist William Hamilton, who showed that close relatives have a biological interest in helping each other because by doing so they indirectly support the success of their own units of heredity, their own genes. Hamilton applied this thinking to the ants, bees, and wasps, pointing out that these animals have a peculiar breeding system, where only females have fathers (males being born from unfertilized eggs). This means that sisters are more closely related to each other than normal. In the usual case (e.g., humans), mothers and daughters are 50 percent related, as are sisters. In the hymenopteran case, a female gets the same genetic input as her sister from their shared father and then 50 percent input from their shared mother. Thus sisters are 50 percent and one-half 50 percent (75%) related, whereas mothers and daughters are just 50 percent related. It is in a worker's reproductive interests to raise fertile sisters rather than fertile daughtersan activity that is aided rather than hindered by the worker's own sterility. There is no need to treat the colony as but one unit for one can see individual interests being played out in this, the most integrated and harmonious of social situation.


Reciprocal altruism. Other models were devised, including one that Darwin himself sensed, even if he did not fully articulate it. Reciprocal altruism works on the principle that when an organism gives help, it is entitled to receive help when needed. Reciprocal altruism can work even among non-relatives, orat the extremeacross species. Certain fish are major predators, but they tolerate other types of fish that swim directly into their mouths and pick out harmful bacteria and fungi on their gums. The predators practice dental hygiene and the cleaners get a good meal because the larger fish does not swallow the smaller fish in its mouth. Everyone benefits.


Evolutionary equilibrium. Evolutionists turned to game theory in cases where participants adopt various strategies to succeed in the light of the fact that other players (in biological terms, other members of the species) are also trying to succeed. In The Selfish Gene (1976), a provocative popularization of this theory, British biologist Richard Dawkins showed how certain evolutionary situations achieve equilibrium, or reveal what he called "Evolutionary Stable Strategies," when no one member of the group can achieve more than limited benefits, given the conflicting interests of the group. To take one of Dawkins's examples, consider a group with two kinds of members. Some members of the group are "hawks," who in any potential conflict situation are aggressive and will fight if need be. Others in the group are "doves," who always run if a fight looms. One might assume that the hawks would dominate and that selection would produce a population without any doves. But this is not so. A hawk's encounter with another hawk always leads to a fight, which may end with one hawk injured or dead. Doves, however, never get beaten up because they run. So, on average, there is a cost to being a hawk. But doves cannot dominate either, because, on average, there is a cost to being a dove. Hawks always win confrontations between a hawk and a dove. The birds of the group therefore end up in a balanced if uncomfortable midpoint, with neither hawks nor doves able to increase their representation at the expense of the other.

Armed with these theories, naturalists and experimentalists turned to the larger world to determine if they could understand the social behavior not just of insects and fish, but of more complex animals like birds and mammals. The widest range of topics was covered. Notable was a study (led by Cambridge biologist Tim Clutton Brock) of red deer on an island off the coast of Scotland that showed how male deers strive to capture harems and will compete (or not) as it proves to be in their interest, and how female deers, which seem to be controlled by males, will in turn employ tricks and strategies to improve their reproductive options and results. A female wants her offspring, particularly her sons, sired by a male who will pas on his superior breeding qualities. Another study (conducted by Cambridge biologist Nicholas Davies) looked at the dunnocks (hedge sparrows), a bird that has the widest of breeding patternsmonogamy, polygyny (one male, several females), polyandry (one female, several males), and something primly referred to as polyandryny (group sex, with several males and several females). By doing DNA fingerprinting on the birds and their offspring, researchers could trace relationships, demonstrating just how much behavior was controlled by reproductive interests. This study revealed that dunnocks do not raise chicks with whom they have little reason to think they have real blood ties. Moreover, a dominant male (an "alpha") will tend to spend more time chick rearing and to have more offspring than a lesser male (a "beta"). Another study in Holland (reported by ethologist Franz de Waal) looked at relationships within a troop of chimpanzeeshow males needed female help to dominate a situation, and how different alliances would be formed according to different interests. Two weaker males might prefer to gang up to defeat a stronger male, rather than simply acting individually.

Edward O. Wilson. Research went ahead with speed and enthusiasm, and before long, the science of the evolution of social behaviornow called sociobiology was ready to take its proper place in the Darwinian family, along with paleontology and the other subjects. But controversy loomed. Darwin had wanted to apply his ideas to humans, and in the The Descent of Man (1874) he did just that, as did Darwinian scientists who came later, in particular, Harvard entomologist Edward O. Wilson. In a major overview of the field, Sociobiology: The New Synthesis (1975), and later in a work addressing the human species, On Human Nature (1978 ), Wilson argued that nearly every aspect of human life and nature is a function of biology, or, more accurately, the genes as fashioned by natural selection. Sexual differences, family structures, religion, warfare, language, and much more, are the end result of natural selection working on the units of heredity. Even homosexuality could be biologically caused, as gay and lesbian members of the family aid close relatives, like sterile mammalian workers at the nest. Moreover, argued Wilson, while humans may be able to change some things, biology will be resistant and, in many respects, people are locked into being what they are. Utopian plans for change would be counterproductive.


Early objections to sociobiology

As expected, there were many objections to the new field of sociobiology. Social scientists became tense because they felt that biologists were poaching on their domain. Rather than accepting biology as a complement or an aid to social science, they saw it as a threat and feared sociology would vanish and sociobiology (social-group division) would take its place. Feminists abhorred what they considered a direct attack on their ideology, which held sexual differences and family structures to be purely cultural rather than biological constructions. Darwin was painted as the archetypical Victorian male chauvinist, and sociobiology was seen as an excuse for the status quo that oppresses women and children. Marxists, and this included some eminent biologists, felt that a biological approach was a travesty of the truth, because it pretended that evolution and natural selection had accomplished what was truly a function and result of economic deprivation. Their ideological ancestor, Friedrich Engels, had inveighed against a reductionist approach to understanding, and human sociobiology was the worst of all possible offenders.

Interestingly, the one group that might have been expected to explodethose members of the Christian community interested seriously in sciencewas far more receptive. Creationists, of course, would have nothing to do with any evolutionary science, and they fully enjoyed the controversy that pitted evolutionist against evolutionist. More moderate Christian thinkers reacted in a different way. Although they hardly welcomed human sociobiology with unalloyed joy, they could see that the new science was a serious approach to serious problems, and responded in this spirit. Even Christians drawn to feminism and Marxism realized that there was more to life than simple matters of culture, tradition, and economics. God, they argued, is not a social constructivist.

Later interpretations

By the dawn of the twenty-first century, much of the dust had settled. There is certainly no question that some of the early enthusiasts for sociobiology let their imaginations outstrip the evidence, filling in gaps with creative intelligence. But some of the most interesting work has come from evolutionists who have actually turned biology on its head. Sarah Hardy, for instance, has argued that female humans conceal ovulation, thereby ensuring that males have to stay around and participate in child rearingif they do not, they cannot be sure of paternity. In other words, in good feminist fashion, she argues that the evolutionary scales are balanced, and may, if anything, be tipped in favor of women. Others have argued that sociobiology underlies the unity of the human community, thus belying fears of racism. People can, of course, interpret biology and form prejudices as they will, but there is no reason for thinking that biology supports or contains such prejudices.

In many other ways, human sociobiology transcends the parody portrayed by the critics. Typical of modern sociobiological research (often now hidden under less flamboyant and provocative names like human behavioral ecology or evolutionary psychology ) is a careful study of homicide by the Canadian researchers Martin Daly and Margo Wilson. They have shown that murder falls into stable patterns, which lend themselves to a sociobiological interpretation. For example, the killing of children by parents (other than infanticide, which follows its own rules) is almost always perpetrated by step-fathers rather than biological fathers. This is a pattern very much in line with the rest of the animal world, where it is well-documented that males moving in on a new female will attack her already-existing young, so that their own new offspring get more attention. Paradoxically, when Daly and Wilson began their study, they could find no firm evidence against which to test their hypotheses. Authorities thought it prejudicial to reconstituted families to collect statistics on whether or not family violence involved step-parents or biological parents. It was only when Daly and Wilson insisted on the collection of the data, that the patterns emerged.

Implications for religion and philosophy

Sociobiology suggests much to the philosopher or the theologian interested in the deeper questions about human nature. Traditional approaches to evolution and ethicsso-called social Darwinismargue that moral codes follow from the need to cherish and promote the evolutionary process. Thus, British philosopher Herbert Spencer endorsed laissez-faire economics in the name of evolution, seeing it as part of the struggle for existence in the human world. Just as in nature the weak fall because they are inadequate, so in society the weak fall because they are inadequate; this, argued Spencer and his fellows, is nature's way and to try to prevent it is to lead to decay and degeneration. Most sociobiologists avoid arguments of this type. Following more sensitive thinkers, like Darwin's "bulldog" Thomas Henry Huxley, sociobiologists refuse to identify the "evolved" with the "good." They see that although evolution can produce the worthwhile, evolution can also produce the absolutely horrible. Although Daly and Wilson think that child killing may be biologically motivated, they stress that it is not moral in any sense. Their work indeed is intended to throw light on the problem, so that people might change or control such behavior. Male lions and lemmings may kill the young of other males, but this is no reason for humans to do likewise.

There are, however, other ways to tackle issues of morality, while still bringing sociobiology to bear. First, one might argue, as many do, that humans are social animals in the extreme, and as such need mechanisms to get on with other humans. If humans did not have adaptations to protect against diseaseas native Tasmanians did notthe human species would soon die out. The same is true of behavioral and motivational adaptations. By nature people are selfishthat is a direct consequence of the struggle for existencebut this selfishness, untamed and unmodified, would lead to disaster in social situations. People would quarrel and fight nonstop and be unable to work together. So they need special adaptations to overcome this counterproductive consequence of natural selection. But what could these adaptations be? Humans are too complex simply to have social sentiments hardwired in, like ants. Apart from anything else, simple hardwiring gives no room for reflection and regrouping when things go wrong or when facing new or unexpected situtations. Humans need something more subtle than the simple rules of social behavior followed by the hymenoptera. Here, argue sociobiologists, is the place for a moral sense, something that humans have innately (that is, put in place by selection and backed by the genes) that allows them to meet social demands and to work together with other humans. People have a sense of moral obligation that they ought to help others (and equally a sense of moral obligation that when they are in need, others ought to help them). It is something that aids people in social situations, and at the same time is obviously an instrument with sufficient subtlety and flexibility to allow people to adapt as situations and environments change. In other words, biologists of human social behavior argue that ethics has been put in place by human biology to make people good cooperators. Ethics is an adaptation.

The atheistic interpretation. What implications does this discussion have for the foundations of ethics (what philosophers call metaethics )? If ethics, the human sense of right and wrong, is an adaptation, is it thereby no more than a subjective sentiment, on a par with a liking for certain foods? The answer depends on one's theological commitments. Atheists and skeptics will probably conclude that there are no foundations, that ethics is simply an epiphenomenon of the genes, with no more ultimate meaning than any other adaptation like eyes or teeth. However, the tendency toward ethical behavior is not simply a subjective sentiment like a fondness for ice-cream. For a start, it has to be universally shared by other humans (except perhaps psychopaths), otherwise it would not function. Moreover, subjective emotion or not, it has to have an illusion of objectivityof a foundationotherwise it would simply collapse, as people decided to cheat and look after themselves alone. A conscience is essentially a part of the moral sense, even if (especially if) it is just an adaptation like everything else. But ultimately, the nonbeliever thinks that there is nothing to ethics but a naturalistic explanation of where it came from and why it has the hold on people that it does.

The Christian interpretation. What if one is a Christian or a member of any other theistic religion, however? Can this rather bleak philosophy take on a different, more hopeful and fulfilling hue? If one is a believer, one can (and must) surely interpret the situation as God's way of instilling an ethical sense in humankind. After all, the believer has to agree that God has instilled an ethical sense, and if one is an evolutionist then surely the sociobiological scenario is as plausible a scenario as any other. In fact, the Christiancertainly the Christian who takes seriously the teaching of Thomas Aquinasknows this already. Natural law is something imposed upon us by the way that God has created humans. Human sexuality is intimately bound up with the fact that (in the first place) there are two sexes, and that to fulfill this sexuality people have the various emotions and organs that they do. Moral dictates follow from the nature of this creation. Promiscuity, for instance, is immoral because it is a violation of the naturalthat is, God-made and God-ordainedbonds of erotic love that can and should exist between two people exclusively. For the theist who accepts sociobiology, ethics is part of creation, and the emotions and reasons that constitute it are very much part of the God-made natural order. Hence, inasmuch as one's moral sense (and the awareness to which it leads) is something natural, it is something to be cherished and obeyed and respected by God's creatures.


Sociobiology and original sin. But what about original sin? No one who has lived through even part of the past century can be insensitive to this issue, and those who were wont to downplay its significance in theology are now surely in the minority. How else does onehow else does the Christianexplain the evils of national socialism and all of the other vile movements of the past hundred years? The idea that humans are in some sense taintednot wholly bad but with a dark side to their naturesis pressing on the nonbeliever and obligatory for those who think that Jesus was the Christ, the Son of God who died on the Cross for the sins of humans. The traditional position, that of Augustine of Hippo, is that the sins of Adam and Eve are transmitted to us all through sexual intercoursepeople inherit their faults. No evolutionist can take this literallyindeed, it is unlikely that Augustine, who was sensitive to the development of knowledge and who had full awareness of the need to interpret the Bible allegorically, would now interpret the Adam and Eve story literally. He too would feel a need for revision.

A sociobiological approach shows a way of updating the belief in original sina way that takes modern science seriously and yet in no sense denies or belittles the significance of such sin. Sociobiology starts with the fact that humans are destined to be selfish animalsthat is the way of natural selection. Group selection is no longer a viable mechanism, and all must be interpreted in the light of advantage to the individual. If people were not selfishif they did not take for ourselvesthen they would have become extinct long ago. But at the same time, sociobiology stresses that humans are social animals that need to get on together. So humans evolved ethics. But humans are not locked in blindly, like ants. They have moral sentiments, and though they may not have much choice about the moral sentimentsa fact that no one, other than existentialists at their most extreme, has ever deniedthey can decide whether or not to obey the sentiments, as it pleases them. And sometimes it does please people, and sometimes it does not. Sometimes people continue in their selfish ways even though others would suffer, and sometimes they listen to conscience and do the right thingsometimes indeed they do not even have to listen to conscience before doing the right thing. In other words, humans are an ambivalent mixture of good and illsometimes doing the kind and charitable thing, and sometimes failing in their obligations and duties. And humans are this way in their deepest nature, something they inherit rather than create anew. And that surely is precisely the Christian position on original sin. People are tainted. They cannot escape this. It is inherited as part of human nature. But humans have the abilities to do the right thing, to act against this side to their nature. Sometimes they do, and sometimesall too oftenthey do not.

Freedom and determinism. Finally, one must address the question of freedom and determinism. It is an absolutely crucial part of Christian, as well as Jewish and Muslim, belief that people are made in the image of God, and therefore have the freedom to choose between good and ill. God may know what people will do, but God does not constrain them in what they will do. Each person's faults are his or her own responsibility. Can such a conception of freedom be reconciled with human sociobiology, a discipline that some critics complain is committed to genetic determinism? Those who dislike human sociobiology argue that sociobiologists portray humans as marionettes on the strings of the genes, with no more power of choosing right or wrong than the puppets Punch and Judy have of living in domestic harmony. People are as clockwork, set up and simply set to run. The wife beater resorts to violence because he is male and that is the way of men. The child whines because it is a child and that is the way of children. The racist has genes for xenophobia and is no more at fault that the person with Down syndrome who cannot pass an intelligence test. Biology is destiny, and that is the end to freedom.

A more thoughtful approach, however, shows that Christian conceptions of freedom and sociobiological conceptions of determinism are not necessarily contradictory and can indeed be complementary. On the one hand, the Christian recognizes that freedom does not mean stepping outside of the laws of nature, for in that direction lies randomness or madness. Augustine, again, saw that true freedom means working according to human nature. God is free and yet cannot do ill. It is against God's nature to do ill. Likewise, people are free, but what they do is part of their nature. That is why God knows what will happen even though God does not control or will it. People are free to kill their children and yet most could no more do so than they could jump over the Atlantic Ocean. They are free to refrain from boasting, and yet could no more do so than they could climb Mount Everest. Conversely, for all the talk about determinism, the sociobiologist recognizes, in fact insists on, a dimension of human freedom. Ants are hardwired to do what they do. They have no choice. But humans are not hardwired to do what they do. They do have a choice; they must have a choice if they are to function as the complex social animals they have evolved into. Humans may be part of the causal nexus, but they have a dimension of freedom denied to rocks or lower animals and plants. If ants are like cheap rockets shot off and then, once fired, beyond further control, humans are like expensive rockets with feed-back mechanisms enabling them to respond to changes in the target. In short, the Christian recognizes that human freedom takes place within rules and restraints, and the sociobiologist recognizes that human determinism is open to dimensions of choice and alternative action. Why then should not the Christian and the sociobiologist work together to find a meeting point on these issues, harmony rather than conflict? Far greater gaps exist between Christians and their critics than between sociobiologists and their critics.

Conclusion

Other issues could be raised, and some are still far from resolution. If evolutionary theory is true, then presumably human mindsin line with everything else biologicalare part of gradual development in time. Yet Christians have tended to see minds (and souls) as a sharply demarcated phenomenoneither humans have them or they do not. Animals do not have souls; humans, all humans, do. There is a brittle break in nature at this point. This is certainly a place where some compromise is necessary if consistency is to be achieved. There is surely much work and serious rethinking still needed on the connection (if there is one) between the human mind, either the Christian human mind or the sociobiological human mind, and the teachings about the nature and existence of the immortal soul. But these and other problems are challenges, not road blocks. Certainly the larger Christian community was correct in its intuitions when, on the arrival of human sociobiology, it took a position of welcome, albeit guarded welcome, rather than of hostility and rejection. All human understanding is grist for the theological mill, and sociobiology is no exception.


See also Behavioral Genetics; Darwin, Charles; Determinism; DNA; Eugenics; Evolution, Biocultural; Evolution, Biological; Freedom; Genetic Determinism; Genetics; Memes; Mutation; Nature versus Nurture; Selfish Gene; Sin


Bibliography

caplan, arthur l., ed. the sociobiology debate: readings on ethical and scientific issues. new york: harper and row, 1978.

clutton-brock, timothy h.; guiness, fiona e.; and albon, steve d. red deer: behaviour and ecology of the two sexes. chicago: university of chicago press, 1982.

daly, martin, and wilson, margo. homicide. new york: de gruyter, 1988.

darwin, charles. the origin of species (1859). new york: bantam classic, 1999.

darwin, charles. the descent of man (1871). amherst, n.y.: prometheus, 1997.

davies, nicholas b. dunnock behaviour and social evolution. oxford: oxford university press, 1992.

dawkins, richard. the selfish gene. oxford: oxford university press, 1976.

degler, carl n. in search of human nature: the decline and revival of darwinism in american social thought. new york: oxford university press, 1991.

dewaal, franz. chimpanzee politics: power and sex among apes. london: cape, 1982.

hrdy, sarah blaffer. the woman that never evolved. cambridge, mass.: harvard university press, 1981.

kitcher, philip. vaulting ambition: sociobiology and the quest for human nature. cambridge, mass.: mit press, 1985.

ruse, michael. sociobiology: sense or nonsense? 2nd edition. dordrecht, netherlands: reidel, 1985.

ruse, michael. taking darwin seriously: a naturalistic approach to philosophy. 2nd edition. amherst, ny: prometheus, 1988.

ruse, michael. can a darwinian be a christian? the relationship between science and religion. cambridge, uk: cambridge university press, 2001.

ruse, michael. the evolution wars: a guide to the controversies. santa barbara, calif.: abc-clio, 2001.

wilson, edward o. on human nature. cambridge, mass.: harvard university press, 1978.

wilson, edward o. sociobiology: the new synthesis. cambridge, mass.: harvard university press, 1975.

michael ruse

Sociobiology

views updated Jun 11 2018

SOCIOBIOLOGY

Sociobiology denotes the attempt to provide a biological explanation for the social behavior of animals, including humans, although the focus is more often on social insects such as ants and honey bees. Because ethics is also concerned with social behavior among human beings, achievements in sociobiology may also have implications for a possible science of ethics.


The Darwinian Background

As a term the word sociobiology first appears in Principles of Animal Ecology (1949) by Warder C. Allee, Alfred E. Emerson, et al., but the subject matter is much older. In On the Origin of Species (1859), Charles Darwin argued that there is constant population pressure brought on by the fact that numbers of organisms always outstrip food and other resources. There is therefore a constant struggle for existence. Some organisms have features enabling them to better succeed in the struggle, and thus there is a natural selection of the winners over the losers. This leads to evolution, but evolution of a special kind. Selection produces and perfects features useful in the struggle—organisms have adaptations such as the hand and the eye that aid them in survival (and, even more importantly, to reproduce).

Darwin realized that behavior is as much part of an animal's repertoire in the struggle for existence as are any physical adaptations. He was particularly interested in social behavior such as that of the hymenoptera (the ants, bees, and wasps). His interest was spurred not only by the phenomenon itself but because (in Darwin's opinion) such behavior seems to go against the workings of selection. Darwin believed that the struggle for existence pits every organism against every other organism, and hence selection can only promote adaptations that are valuable to the individual. (In contemporary language, Darwin was an individual selectionist rather than a group selectionist.) How then do organisms develop social features that seem to help the nest, perhaps even at the cost of total sacrifice of the interests of the individual? Sterile workers apparently spend their whole lives looking to the needs of their mothers and siblings. Eventually Darwin came to believe that the nests of social insects should be regarded as one large superorganism, rather than a group of individuals working together. In that way, the individuals in a nest are more parts of the whole (like the heart and liver are parts of the human body) rather than organisms existing in their own right with their own interests.

For a number of reasons, in the century after On the Origin of Species was published, the study of behavior by biologists lagged behind other areas of evolution. First behavior is much more difficult to record and measure than are physical characteristics. Experimentation is particularly difficult, for it is notoriously true that animals change their behaviors in artificial conditions. Secondly practitioners of the new social sciences thought that they exclusively should examine behavior, and that biology had no place in their endeavors. Unfortunately there existed a strong ideology that experience and training are the cause of most, if not all, behavior, and hence evolutionary factors tended to be discounted before any research was done. Continental students of behavior known as ethologists were a notable exception to this indifference to evolutionary theory, although their work was (as judged by twenty-first century standards) hampered by unjustified assumptions about the significance of group selection.


Breakthroughs in the 1960s

Major breakthroughs occurred in the 1960s, due, in large part, to the work of William Hamilton (1936–2000) in England. Promoting the theory now known as kin selection, Hamilton, then a graduate student, pointed out that in modern terms, selection is equivalent to passing on a particular individual's genes (or rather copies of those genes) more effectively than competitors. However when a person's close relatives reproduce, because they share copies of that person's genes, they also pass on those same copies: reproduction by proxy as it were. Normally it is biologically most efficient to reproduce oneself because (except for identical twins) an individual cannot be genetically more closely related to any other being. Hamilton argued there are some exceptions to this general rule. The hymenoptera particularly have an unusual reproductive system, with females having both mothers and fathers and males having only mothers. Queens get all the sperm they will ever use on the nuptial flight. To produce a female, the queen releases a sperm; in contrast, in producing male offspring, no sperm is released. Thus sisters (50% ③ + 50% ♀ x ½ = 75%) are more closely related than mothers and daughters (50% ♀ x ½ + 50% ③ x ½ = 50%), and so, from an evolutionary perspective, a nest member is better off raising fertile sisters than fertile daughters. From an individual selection perspective, sociality is advantageous.

After Hamilton others proposed theories using an individualistic perspective. One important contribution was Robert Trivers's notion of reciprocal altruism, based on the you scratch my back and I'll scratch yours principle, which holds that some forms of sociality succeed because organisms gain more through cooperation than through conflict. Also significant were insights based on the use of game theory, particularly the idea of an Evolutionarily Stable Strategy (ESS). A whole group is sometimes less well adapted than it could be because self-interest is paramount. Sex ratios are a case in point. Females do not need a large number of males for fertilization. But because 50:50 seems to be a more stable balance in the population, the group maintains a surplus of males, instead of a more efficient 10:90 male to female ratio. Building on ideas like this, the study of evolution started to change dramatically, and by the 1970s the study of social behavior, in theory and in practice, became one of the most advanced and exciting areas of evolutionary inquiry. The ideas were presented in popular form by British biologist Richard Dawkins in his The Selfish Gene (1976), and in what became the bible of the movement and gave the field its name, Sociobiology: The New Synthesis (1975), by the American scholar of the study of social insects, Edward O Wilson.


Controversies

These works, Wilson's in particular, were highly controversial, mainly (although not exclusively) because they extended to humans. Much like Darwin himself, having surveyed social behavior in the animal world from the most primitive forms to the primates, Wilson argued that Homo Sapiens is part of the evolutionary world in its behavior and culture. Although he did allow that experience and training can have some effects, Wilson believed that genes are the real key to understanding human thought and behavior. In male-female relationships, in parent-child interactions, in morality, in religious yearnings (a very important phenomenon for Wilson, a Southerner), in warfare, in language, and in much else, biology matters crucially.


Social scientists and left-leaning biologists (especially Richard Lewontin and Stephen Jay Gould), and philosophers (especially Philip Kitcher in a witty attack, Vaulting Ambition), accused sociobiologists—particularly human sociobiologists—of a multitude of sins. Epistemologically these detractors judged the work of sociobiologists to be false, and then (not entirely consistently) charged them with producing ideas and theories that are not falsifiable. One particularly effective rhetorical charge was that sociobiologists's claims are akin to the Just So stories by Rudyard Kipling, in which a fantastical tale is created (i.e., that of how the elephant's nose is long because it was pulled by a crocodile) and then is alleged to be fact. Sociobiologists were also found to be wanting ethically. Their work was attacked as sexist, racist, homophobic, capitalist, and in short, guilty of every possible transgression that exists in a patriarchal, unjust society. They were accused of supporting the status quo in Western societies, and of pretending to give genuine scientific answers to bolster what were really ideological convictions.


There was undoubtedly some truth to all of these claims. Yet some change can be progress, and there is little doubt—at the animal level particularly—that evolutionists have taken full note of critics' complaints and worked hard to address them. Modern techniques, particularly those that employ the insights of molecular biology, have been of great help here. For instance many sociobiological claims concern parenthood. If males are competing for females, for instance, and (as in birds) males are also contributing to childcare, one expects efforts to be tied to reproductive access and success. But while it is difficult if not impossible to determine paternity with traditional methods, that Gordian Knot is cut as soon as one starts using genetic fingerprints. Not only are the scientific claims testable but in many cases they have been found to be correct. Animal sociobiology is no more tentative than other scientific fields. It can be persuasively argued that in science bold conjectures are needed in abundance. However when those conjectures are accepted as fact without being tested, there is a problem. Science requires continual, rigorous challenge.

Human sociobiologists argue that they too have theories that can be, and are, put to the test, such as theories about infanticide, showing that this occurs when and generally only when it is in the biological interests of parents not to have all of the children to which they (or sometimes, rivals) have produced. One well-known theorem (with much support in the animal realm) asserts that females who are more fit will tend to skew birth rates toward males, and less fit females toward females. The reason for this is that even unfit females generally get impregnated, whereas if there is competition among males—and there usually is—the fitter male tends to get the prize. Hence because fit mothers are more likely than unfit mothers to have fit offspring, for fit mothers having males is a good strategy, whereas for unfit mothers having females is a good strategy. There is incidentally no necessary presumption that this always requires conscious intention—fluctuating hormones, for instance, might be the proximate causes. Human sociobiologists argue that this also occurs in human societies, with the members of upper classes tending to dispose of daughters, either physically by allowing them to die or giving them away shortly after birth, or through other methods that effectively prevent reproduction even without killing (for instance, by forcing daughters into religious orders that require celibacy thereby effectively preventing them from reproducing). In recent years, human sociobiology has changed into what is now called evolutionary psychology. The emphasis is less on behavior and more on the mental traits that lead to behavior. This view is still philosophically controversial, with much debate about how and whether one can talk of psychological characteristics as being innate (and how one would test the theory).


Sociobiologists have countered vigorously against the social and ethical charges levied against them. Almost without exception, human sociobiologists have not had significant social agendas and are greatly concerned by the misuse that can (and sometimes is) made of their work. They repudiate strongly the charge that they are crypto-nazis or subscribers to other vile doctrines, and deplore the fact that sometimes people favorable to these ideas invoke the authority of sociobiology in support. They stress that differences between races, for instance, are far less than similarities, and in any case differences in themselves do not necessarily spell superiority or inferiority. Although their work has been much criticized by feminists, human sociobiologists respond that pointing out differences between males and females is not in itself sexist. Indeed one might argue that not to recognize differences can be morally wrong. If boys and girls mature at different rates, insisting that they all be taught in the same ways could be detrimental to both sexes. In more specific issues also sociobiology is not necessarily erroneous or promoting an immoral agenda. To hypothesize that something such as sexual orientation is dictated by an individual's genes (and that there is a pertinent underlying evolutionary history to explain it) could be a move toward recognizing that all people are equally worthy of moral tolerance and respect.

There is ongoing philosophical debate over all of these issues. In the early twenty-first century there is renewed interest in the possible evolutionary underpinnings of religion. It is clear that sociobiology—animal and human, and by whatever name the field is known—is not about to disappear, and is in fact a thriving area of inquiry.


MICHAEL RUSE

SEE ALSO Aggression;Animal Tools;Darwin, Charles;Ethology;Evolutionary Ethics;Game Theory;Nature versus Nurture;Scientific Ethics;Selfish Genes;Social Darwinism;Sociological Ethics.

BIBLIOGRAPHY

Darwin, Charles. (1859). On the Origin of Species. London: John Murray.

Dawkins, Richard. (1976). The Selfish Gene. Oxford: Oxford University Press.

Hamilton, William D. (1996). Narrow Roads of Gene Land: The Collected Papers of W. D. Hamilton. New York: W.H. Freeman/Spektrum.

Kitcher, Philip. (1985). Vaulting Ambition. Cambridge, MA: MIT Press.

Ruse, Michael. (1979). Sociobiology: Sense or Nonsense? Dordrecht, The Netherlands: Reidel.

Trivers, Robert L. (1971). "The Evolution of Reciprocal Altruism." Quarterly Review of Biology 46: 35–57.

Wilson, Edward O. (1975). Sociobiology: The New Synthesis. Cambridge, MA: Harvard University Press.

Wilson, Edward O. (1978). On Human Nature. Cambridge, MA: Cambridge University Press.

Sociobiology

views updated May 29 2018

Sociobiology

MATE ATTRACTION AND SELECTION

ALTRUISM AND AGGRESSION

TESTING SOCIOBIOLOGICAL THEORIES

BIBLIOGRAPHY

The scientific study of the social behavior of biological systems from an evolutionary perspective is known as sociobiology, a term coined by the entomologist and biologist Edward O. Wilson in 1975. Researchers from a diverse array of disciplines including biology, psychology, sociology, anthropology, and archaeology study social behavior from a sociobiological perspective. According to this perspective, the social behavior of animals, including humans, has been shaped by the process of natural selection in which any behavior that increases the ability of an individual to live to reproductive age and to successfully reproduce subsequently becomes more prevalent in future generations. Sociobiologists therefore attempt to understand how current social behavior would have provided a reproductive advantage to individuals of previous generations. To facilitate this process researchers identify problems that social beings recurrently faced over evolutionary history and then determine the behaviors that would have been adaptive to successfully deal with these problems. The term sociobiology has now largely been replaced with the term evolutionary psychology. Using this approach, researchers have found empirical support for the evolutionary origins of a number of social behaviors including mate attraction and selection, helping behaviors, and aggression.

MATE ATTRACTION AND SELECTION

One of the most influential theories of mating behavior is the parental investment theory proposed by Robert L. Trivers in 1972. Trivers postulated that in sexually reproducing species the sex that invests the most in offspring will be more selective in whom they choose as mates whereas the sex that invests the least in offspring will compete more with each other for sexual access to the more selective sex. In humans, the minimal parental investment that a woman must expend on a child involves the nine months of gestation and parturition, plus a period of lactation that can last from several months to a few years. For men, the minimal parental investment can conceivably involve a single sexual encounter. Given that women are a more limited reproductive resource, competition among men to mate with women should have been stronger during evolutionary history than competition among women to mate with men. Consistent with the predictions derived from this theory, research has shown that men are more willing than women to take advantage of short-term sexual opportunities with different mates. In comparison, given the higher costs of reproduction for women, they are more selective than men in whom they choose as sexual partners and tend to desire longer-term relationships.

Parental investment theory also makes predictions regarding the traits men and women should find attractive in each other. If men tend to prefer short-term sexual opportunities to maximize their reproductive success, then they face the problem of identifying which women are fertile. Certain physical cues are associated with fertility, and it has been found that men are more attracted to women that possess these physical traits. For example, women with a waist-to-hip ratio around .70 (where the waist is 70 percent the size of the hips, producing a curvy appearance) and women with more feminine facial features (e.g., larger eyes, smaller chin) have been found to possess high amounts of estrogen and thus are relatively more fertile. Men are also more attracted to young women, perhaps because womens fertility continually declines through their adult years. By contrast, if women tend to prefer long-term relationships so that their high parental investment can be offset by investments from their mate, then they face the problem of identifying mates that have the ability to accumulate status and resources that can then be shared with themselves and their offspring. Research shows that women are attracted to men with good financial prospects, men who have social status, and men that are more ambitious. Women are also more attracted to men who are older than themselves, because older men have had more opportunity to turn their ambition into actual status and resources.

Once a relationship is formed, people face the problem of maintaining the relationship. David M. Buss (2000) has suggested that for humans jealousy was an important adaptation for maintaining relationships because people who became upset when they were in danger of losing their partner would have experienced greater reproductive success than those who did not. He also suggested that women and men should differ in the types of cues that activate their jealousy. Whereas a woman can be confident that she is in fact the mother of her children, because of internal fertilization, a man cannot be certain that he is the father. Paternity uncertainty should therefore have made men more sensitive to cues of sexual infidelity of their partners and wary of rivals that are friendly or flirtatious with their partners to ensure that their partners children are also their own children. For ancestral women, securing the resources to raise highly dependent offspring was a challenge. The ability to raise offspring to reproductive age would be severely compromised if paternal investment were to be directed elsewhere, and therefore women should be sensitive to cues indicating emotional infidelity of their partners.

ALTRUISM AND AGGRESSION

Two behaviors that have also received much attention from sociobiologists are altruism and aggression. When presenting his theory of evolution by natural selection in 1859, Charles Darwin commented that his theory was not able to explain why individuals helped others, particularly when these altruistic behaviors limited the reproductive success of the helper. In 1964 William D. Hamilton addressed this problem with his theory of kin selection. He stated that because individuals share a portion of their genes with genetically related individuals, providing assistance to kin can therefore further ones own reproductive success. Helping behaviors should thus be observed to be directed mainly to genetically related individuals. Kin selection theory, although supported by research, could not account for why individuals were observed to provide assistance to unrelated individuals. Trivers addressed this problem in 1971 by proposing his theory of reciprocal altruism, hypothesizing that an individual will help an unrelated individual when the former expects to be the benefactor of assistance from the latter in the near future. Indeed, help is directed to unrelated individuals with the expectation that these acts of kindness will be repaid.

Aggressive behaviors may also have evolved because of the adaptive benefits they bestowed on the aggressor. According to Mark Schaller and colleagues intergroup vigilance theory (2003), it was adaptive for human ancestors to develop a fear of strangers and of individuals who were diseased. One consequence of fear is that it can motivate aggressive behaviors to defend against perceived threats. The ancestors of contemporary humans lived in small groups and relied on each other for survival, and the presence of individuals from another unknown group could have aroused fear because of the possible threat of intruders to ones survival. People who did not fear strangers from other groups may have been more vulnerable to attack, whereas people who did fear intruders and acted to defend themselves and their group would have been more likely to survive. This tendency to respond aggressively to strangers may no longer be adaptive, however, given that humans now live in very large groups that are very diverse. Over evolutionary history people may also have developed a fear of others who were sick or diseased, given that the illness may be contracted and put ones life at risk. Stigmatizing those who were ill and removing them from the group may have been one way to avoid illness given that early humans did not have access to modern-day medicine.

TESTING SOCIOBIOLOGICAL THEORIES

Sociobiological theories are tested in many different ways. Laboratory experiments have been used to test cause-and-effect relationships between variables by manipulating the context study participants are exposed to and then measuring participants responses. Survey studies that ask people to answer questions about their own personalities or about their likes and dislikes have been used a great deal to study, for example, the mate preferences of men and women all over the world. Field studies have been used to observe the natural behaviors of individuals as they interact in small or large groups. Archaeological records have been used to discover the types of tools human ancestors used to hunt game or to study the evolution of brain size. In addition, public records recording the behaviors of citizens of various countries over hundreds of years exist, and these records have been used to test sociobiological hypotheses regarding homicide (Daly and Wilson 1988) and the effects of birth order on behavior (Sulloway 1996).

Sociobiology is still considered a controversial field by many. Sociobiologists study current social behavior and then make conclusions about what life must have been like for humans living thousands of years ago. Because what happened in the distant past can never truly be known, opponents of sociobiology suggest that researching current behaviors does not provide insights on the evolutionary origins of these behaviors. Sociobiology has also been blamed for justifying negative social behaviors such as male violence against women and intergroup violence. Stated differently, suggesting that social behaviors evolved because they were adaptive implies that these behaviors are natural and acceptable. Although explaining why behaviors exist does not necessarily justify the existence of the behavior, many sociobiologists have not always made the effort to differentiate explanation from justification.

SEE ALSO Darwin, Charles; Evolutionary Psychology; Nature vs. Nurture; Spencer, Herbert

BIBLIOGRAPHY

Buss, David M. 2000. The Dangerous Passion: Why Jealousy Is as Necessary as Love and Sex. New York: Free Press.

Daly, Martin, and Margo Wilson. 1988. Homicide. Hawthorne, NY: Aldine de Gruyter.

Darwin, Charles. 1859. On the Origin of Species by Means of Natural Selection; or, The Preservation of Favoured Races in the Struggle for Life. London: Murray.

Hamilton, William D. 1964. The Genetical Evolution of Social Behaviour I and II. Journal of Theoretical Biology 7 (1): 116 and 1752.

Schaller, Mark, Justin H. Park, and Jason Faulkner. 2003. Prehistoric Dangers and Contemporary Prejudices. European Review of Social Psychology 14 (4): 105137.

Sulloway, Frank J. 1996. Born to Rebel: Birth Order, Family Dynamics, and Creative Lives. New York: Pantheon.

Trivers, Robert L. 1971. The Evolution of Reciprocal Altruism. Quarterly Review of Biology 46 (1): 3557.

Trivers, Robert L. 1972. Parental Investment and Sexual Selection. In Sexual Selection and the Descent of Man, 18711971, ed. Bernard Campbell, 136179. Chicago: Aldine.

Wilson, Edward O. 1975. Sociobiology: The New Synthesis. Cambridge, MA: Harvard University Press, Belknap Press.

Lorne Campbell

Sociobiology

views updated May 14 2018

SOCIOBIOLOGY


Sociobiology is the study of social behavior from a Darwinian evolutionary perspective. Edward O. Wilson named the field in 1975, when he published Sociobiology, The New Synthesis. Although the book stimulated controversy initially because some mistakenly believed that Wilson's ideas gave aid and comfort to political reactionaries, in the early twenty-first century sociobiology is a well-established field within evolutionary biology.

Sociobiologists (or behavioral ecologists or evolutionary psychologists, as they are also known) analyze the evolutionary foundations of social behavior for all animal species. These researchers treat a social ability as if it were the historical product of natural selection. The process of selection occurs whenever individuals differ genetically in ways that affect their capacity to leave copies of their genes to the next generation, which is usually achieved by having surviving offspring. Selection theory enables the sociobiologist to identify puzzling social traits–namely, those that appear to reduce an individual's reproductive, and thus genetic, success.

Because of their interest in the genetic consequences of social behavior, sociobiologists have focused on those aspects of group formation, cooperation, reciprocity, parental care, and sexual interaction that carry disadvantages, as well as benefits, in terms of individual genetic success. For example, how can one explain the evolution of altruism, in which some individuals forego reproduction in order to help others survive and reproduce? Although altruism would seem to reduce genetic success, the trait is widespread–as, for example, in the self-sacrificing sterile worker and soldier castes of the social ants, bees, wasps, and termites. Moreover, in many social birds and mammals, helpers at the nest also give up a chance to reproduce in order to help rear the offspring of other adults.

In 1964 the biologist William D. Hamilton (1936–2000) offered a novel evolutionary explanation for altruism. He showed mathematically that altruists could increase their genetic success if their personal sacrifices resulted in an increase in the reproductive success of close relatives. Because relatives inherit some of the same genes from their recent common ancestors, discriminating altruism can enable the altruist to pass on his or her genes indirectly via helped kin. Hamilton's theory has been tested and supported by the discovery that altruists of most species generally only assist close relatives, thereby propagating the genes they share with these individuals, which helps maintain the potential for carefully targeted altruism within their species.

The Sociobiology of Human Behavior

Sociobiologists have used the logic of evolutionary theory to examine the social behavior of humans as well as that of ants and antelopes. This approach is based on the grounds that humans have certainly differed genetically in the past (just as they do currently). Some hereditary differences have had small but real effects on the development of the brain, thus influencing sensory and motor abilities with corresponding effects on one or another social behavior. If natural selection on hominids occurred in the past, people living in the twenty-first century can be assumed to carry the hereditary social predispositions exhibited by their reproductively successful predecessors.

The logic of the argument means that people, as well as other animals, are expected to act in ways that maximize their genetic success. Thus, if evolutionary theory is correct, altruism in humans should tend to be directed toward close relatives rather than toward genetic strangers, and there is considerable evidence that persons are predisposed to help their kin. Likewise, if past selection has shaped the human sexual psyche, then men in cultures around the world are predicted to find youthfulness, and therefore high fertility, attractive in potential partners whereas women are predicted to find strength, high social status, and thus, wealth to be sexually attractive attributes in men. In the past, men and women with these adaptively different mate preferences surely left more descendants than those people who chose mates at random. Cross-cultural data generally confirm these predictions. Men are endowed with evolved psychological systems that "encouraged" their male ancestors to seek out mates most likely to produce children. Women evidently possess quite different systems that "encouraged" their female ancestors to select protective, wealthy men able to offer above-average parental care to their children, a critical factor in determining the survival of offspring in the past.

The significance of sociobiological analyses for human population issues is obvious. The traits of humans (and all other organisms) that have been shaped by natural selection are expected to have promoted the genetic success of individuals in the past–and in the present as well, to the extent that modern environments resemble those of the past. Because present-day humans are the descendants of individuals who reproduced most successfully, human populations have the capacity to grow exponentially, just as do the populations of all other organisms. The evolutionarily-adaptive drive to reproduce leads the great majority of married couples to have at least one child rather than none at all, with infertile couples often divorcing or adopting or undergoing fertility treatments, despite the onerousness and expense of these options.

Not all aspects of human behavior, however, can be easily explained in evolutionary terms. Currently, the paramount problem in human social behavior for sociobiologists is the demographic transition, the decline in fertility that has occurred as countries have moved toward becoming modern industrial states. Among the several still incompletely-tested evolutionary hypotheses on the demographic transition is one that begins with the assumption that people have an evolved drive for high social status (because in the past this striving was correlated with better-than-average reproductive success). If so, wealthy persons in modern nations with an economically advantaged class may consider themselves in social competition with others of similar status. If this is true, then major investments are required for each offspring in order to provide him or her with the wherewithal for social success. These investments are possible only through a reduction in fertility. Thus, according to this hypothesis, humans' evolved psychological mechanisms might lead individuals in novel modern environments to act in ways that reduce, rather than increase, the absolute number of surviving offspring they produce. Additional research is required to evaluate this and other sociobiological hypotheses, but the discipline has already demonstrated the productivity of evolutionary theory as a tool for investigating human behavior.

See also: Animal Ecology; Biodemography; Darwin, Charles; Evolutionary Demography; Primate Demography.

bibliography

Alcock, John. 2001. The Triumph of Sociobiology. New York: Oxford University Press.

——. 2001. Animal Behavior, An Evolutionary Approach. Sunderland, MA: Sinauer Associates.

Dawkins, R. 1989. The Selfish Gene, 2nd edition. New York: Oxford University Press.

Gaulin, Steven J. H., and Donald H. McBurney. 2001. Psychology, An Evolutionary Approach. Upper Saddle River, NJ: Prentice Hall.

Trivers, Robert. 1985. Social Evolution. Menlo Park, CA: Benjamin Cummings.

Williams, George C. 1966. Adaptation and Natural Selection. Princeton, NJ: Princeton University Press.

Wilson, Edward O. 1975. Sociobiology, The New Synthesis. Cambridge, MA: Belknap Press.

John Alcock

Sociobiology

views updated Jun 11 2018

Sociobiology


A perennial debate about human nature, pitting the idea that behavior is culturally conditioned against the notion that human actions are innately controlled, was rekindled in 1975 when Edward O. Wilson's Sociobiology: The New Synthesis introduced a new scientific discipline.

Sociobiology is defined by Wilson as "the systematic study of the biological basis of all social behavior" and can be described as a science that applies the principles of evolutionary biology to the social behavior of organisms, analyzing data from a number of disciplines, especially ethology (the biological study of behavior), ecology , and evolution . It employs two chief postulates. The first is the interaction principle, the idea that the action of any organism, including man, arises as a fusion of genotype and learning or experience. The second is the fitness maximization principle, the notion that all organisms will attempt to behave in a manner that passes copies of their genes to future generations .

Sociobiology provides several ways to understand the social behavior of an organism, including those acts termed "altruistic." First, social behaviors can be seen as the genetically conditioned attempts of an organism to save copies of its genes carried in others, especially close relatives. Such acts can also be viewed as a form of "genetic reciprocity" in which an organism helps another and the helped organism (or others) repays the help at some time in the future, thereby enhancing the fitness of each of the organisms involved. Finally, cooperative actions can be understood as the result of natural selection operating at the level of groups, in which "altruistic" groups pass their genes on more successfully than "selfish" groups.

In Sociobiology, Wilson, an entomologist specializing in the biology of ants, develops these concepts using the example of social insects. He shows how their cooperative and "altruistic" behaviors, never fully considered by traditional evolutionary biology, can be understood in terms of genetic fitness and natural selection. But the crucial aspect of Wilson's book is his assertion, within a single chapter, that such genetic theories can be applied to the social behavior of primates and man as well as to "lower" animals. Indeed, Wilson contends that scientists can shrink "the humanities and social sciences to specialized branches of biology" and predicts that to maintain the human species indefinitely, we will have to "drive toward total knowledge, right down to the levels of the neuron and gene," statements in which he seems to suggest that human beings can eventually be explained totally in "mechanistic terms."

Broadly, the premise of Wilson's argument finds its origins in the ideas of René Descartes and the mechanists of the eighteenth century such as Julien Offroy de La Mettrie, whose 1748 book, L'homme-machine, helped define the modern biological study of human beings. Wilson argues that if humans are indeed biological machines, then their actions in the realm of society should not be excluded from examination under biological principles, and dramatically defines his goal by stating that "when the same parameters and quantitative theory are used to analyze both termite colonies and troops of rhesus macaques, we will have a unified science of sociobiology."

Wilson's book, especially his statements in the final chapter, generated a storm of controversy. Some feared that a genetic approach to human behavior could be used by racists (and eugenicists) as a scientific base for their arguments of racial superiority, or that delving too deeply into human genetics might lead to manipulation of genes for undesirable purposes. Well-known evolutionary biologists such as Stephen Jay Gould and Richard Lewontin criticized Wilson for stepping over the line between science and speculation. Gould quite openly declared his unhappiness with the final chapter of Sociobiology, stating that it "is not about the range of potential human behavior or even an argument for the restriction of that range from a much larger total domain among all animals. It is, primarily, an extended speculation on the existence of genes for specific and variable traits in human behaviorincluding spite, aggression, xenophobia, conformity, homosexuality, and the characteristic behavior differences between men and women in Western society." Lewontin argued that sociobiology "is too theoretically impoverished to deal with real life," that "by its very nature, sociobiological theory is unable to cope with the extraordinary historical and cultural contingency of human behavior, nor with the diversity of individual behavior and its development in the course of individual life histories."

Feminists have also taken up the cudgel against sociobiology, asserting that it implicitly sanctions existing social behavior with a latent determinism. If, for example, repressive acts are defined as the result of direct genetic influence, the basis for their moral evaluation disappears.

Wilson has responded to his critics energetically and condemns those using sociobiological arguments to support societal evils by equating "what is" with "what should be." Wilson says: "The 'what is' in human nature is to a large extent the heritage of a Pleistocene hunter-gatherer existence. When any genetic bias is demonstrated, it cannot be used to justify a continuing practice in present and future societies. Since most of us live in a radically new environment of our own making, the pursuit of such a practice would be bad biology; and like all bad biology, it would lead to disaster. For example, the tendency under certain conditions to conduct warfare against competing groups might well be in our genes, having been advantageous to our Neolithic ancestors, but it could lead to global suicide now. To rear as many healthy children as possible was long the road to security; yet with the population of the world brimming over, it is now the way to environmental disaster." He goes on to suggest that "our primitive old genes will therefore have to carry the load of much more cultural change in the future" and, indeed, that our "genetic biases can be trespassed" by thinking and decision-making.

Sociobiology seems to have survived its vilification by critics. Indeed, Wilson's vigorous advocacy of a new synthesis between the social and biological sciences has helped bring into the open a debate about the relationship of biology and society that will probably bear a great deal of scientific fruit.

[Gerald L. Young and Jeffrey Muhr ]


RESOURCES

BOOKS


Wilson, Edward O. On Human Nature. Cambridge, MA: Harvard University Press, 1978.

Wilson, Edward O. Sociobiology: The New Synthesis. Cambridge, MA: Harvard University Press, 1975.


PERIODICALS

Lieberman, L., L. T. Reynolds, and D. Friedrich. "The Fitness of Human Sociobiology: The Future Utility of Four Concepts in Four Subdisciplines." Social Biology 39 (Spring-Summer 1992): 158169.

Wolfe, Alan. "Social Theory and the Second Biological Revolution." Social Research 57 (Fall 1990): 615648.

Sociobiology

views updated Jun 08 2018

Sociobiology

A term coined by the eminent entomologist Edward O. Wilson to define a field of study combining biology and social sciences.

In his 1975 work, Sociobiology: The New Synthesis, entomologist Edward O. Wilson first coined the term "sociobiology" to create a new field of study combining biology and social sciences, especially anthropology and sociology. Sociobiologists study the biological nature of human behavior and personality according to the tenet that all social behavior has a biological basis.

The field of sociobiology has not been widely accepted by contemporary theorists of personality and culture. The trend of social thought for several decades has been that humans are by and large responsible for their personal behaviors and for the ways they interact with others and with society as a whole. Wilson and other sociobiological theorists consider many human behaviors to be genetically based, including aggression , motherchild bond, language, the taboo against incest , sexual division of labor, altruism, allegiance, conformity , xenophobia, genocide, ethics , love, spite, and other emotions.

Traditional social scientists, however, debate sociobiology. Feminists have been particularly critical of the new field's view on gender roles. Feminists believe that gender roles are culturally determined. Sociobiologists see gender roles as basic human traits and point out that in almost no culture in the history of the world have women, for example, taken the role of sexual aggressor or exhibited a propensity to collect harems of sexually active mentwo human traits that appear in nearly every culture.

Sociobiologists point to the mother-child bond as one of the prime examples of genetically based behavior. According to sociobiologists, the attachment a mother feels for her infant is a genetically programmed response to the biological need to continue the human gene pool. While this is almost certainly true to some extent, many psychologists and those in the various fields of social science argue otherwise. They point out that non-genetic mothers in contemporary society, for example, adoptive parents and step-mothers, demonstrate a bond just as deep as those between genetic mothers and their children.

Sociobiologists have also tried to explain the prevalence of gender stereotypes across different cultures. As children approach school age in Western culture, their experiences become more social and less domestic as they spend a great deal of time away from home with people other than their parents. During this time, children start to identify with their same-sex peers and learn stereotypical gender roles whether or not these roles are enforced in the home. Sociobiologists believe the current trend to avoid gender-marking is a wasted effort since gender roles are an intractable part of human nature.

Young boys tend to be aggressive in their play , while young girls tend to be reflective, or, to use a term widely applied in sociobiology, coy. This tendency is also seen in other primates and occurs across a variety of human cultures. It is therefore logical to assume that a young boy is naturally predisposed to aggressive behavior while a young girl is naturally predisposed to less violent modes of play. It is also widely held that boys and girls have different intellectual capacities, with boys being more adept at spatial reasoning and girls at verbal. There are reams of standardized test score data backing up such assertions, but it is not clear whether such differences are genetically determined.

Sociobiologists do not claim that aggression in males is acceptable. Even though male domination seems to be the predominant form of social organization, organized societies are not in any way obliged to defer to it. Social structures have for thousands of years modified what might be considered "natural" behaviors. Murder is an example. In preliterate societies murder is sanctioned under a variety of conditions. Human sacrifice, for example, used to play a large role in preliterate societies. But as societies develop, these "natural" tendencies are, necessarily, curbed. Instinctive behavior is replaced by social behavior because a culture sees social behavior as more desirable. While sociobiology may predict patterns of behavior in young children, there is no reason to believe that these tendencies cannot or should not be altered.

If there is any stage of life that most exemplifies the ideas of sociobiologists, it is adolescence . During this period, hormones are changing the body at a pace unmatched during any time in life, and with those changes in physical appearance, behavior also changes. Boys and girls take on social roles during adolescence that are radically different from their roles as children.

Some sociobiologists believe that many of the problems adolescents face in constructing their adult identities have a basis in evolution. There is increasing evidence, for instance, that certain adolescents are genetically predisposed to fall into clinical depressions. Genetic research has shown that many people suffering depression share a genetic abnormality that may only "turn on" if confronted with certain overwhelming social problems such as those faced by adolescents. There is also evidence that a predisposition to drugs and alcohol dependency is genetically determined. Recent studies have found links between several biological functions and anti-social and criminal behavior among adolescents. Included in this list are a slowly developing frontal lobe system in the brain , a variety of genes, a faulty autonomic nervous system , abnormal blood sugar levels, deviant brain waves, and hyperactivity. So, while specific behaviors are not linked to a specific gene or to evolutionary adaptation , a propensity to behave in a certain way, in the absence of more socially acceptable alternatives, may have a partial foundation in biology.

Further Reading

Wilson, Edward. Sociobiologythe New Synthesis. Cambridge, MA: Harvard University Press, 1975

de Wal, Frans B.M. "The Biological Basis of Behavior." The Chronicle of Higher Education, June 14, 1996, p. B1.

Horgan, John. "The New Social Darwinists." Scientific American, October, 1995, p. 174.

. "Revisiting Old Battlefields." Scientific American, April 1994, p. 36.

"Irven DeVore." Omni (interview) June 1993, p. 69.

Laying, Anthony. "Why Don't We Act Like the Opposite Sex?" USA Today, January 1993, p. 87.

sociobiology

views updated May 14 2018

sociobiology Some animals lead very solitary lives, but others, including humans, live in complex social groups. Sociobiology is the branch of biology that deals with the behaviour of these social animals. The term was coined by the Harvard entomologist, Edward O. Wilson, whose book of the same name brought to a wider public several important developments in theoretical biology that had been made during the 1960s and 1970s.

These developments addressed the phenomenon of altruism, which had long been seen as a problem in evolutionary biology (see evolution). Altruism is defined by biologists as any act that makes the recipient more likely to survive and reproduce while reducing the donor's own reproductive success. Since natural selection cares only about reproductive success, it seemed that altruism could not have evolved by such a process. And yet it was everywhere visible, from the parental care exhibited by mammals and birds to the selfless devotion of worker ants to their nest.

In the 1960s and 1970s, two solutions were proposed to this problem. The first of these was the theory of kin selection, which was first proposed by W. D. Hamilton in 1964. Hamilton argued that the spread of a gene did not depend only on its effects on the reproductive success of the body in which it sat, but also on its effects on the reproductive success of close kin, because they are likely to carry the same gene. A gene that caused its owner to risk his or her life to save several siblings, each of whom has a 50% chance of having the same gene, would spread quickly through the population, even if it often caused its owner to die childless. As Richard Dawkins put it graphically in The Selfish Gene (1976), the theory of kin selection showed that genes could proliferate by helping copies of themselves in other bodies.

Hamilton's theory of kin selection explains altruism between closely related individuals, but what about altruism between unrelated organisms? This is where the second solution to the problem of altruism comes in. In 1971, Robert Trivers argued that altruism may often be merely apparent, since it will turn out on a closer analysis to be a reciprocal exchange of favours. Trivers dubbed the phenomenon ‘reciprocal altruism’, and argued that the appearance of altruism is generated by the fact that the reciprocation may not be immediate. For example, a vampire bat may give up some of its food to a hungry companion one day without any immediate reward, but only because it expects that the favour will be returned in the future. In the years following Trivers' initial paper many biologists thought that reciprocal altruism was widespread in the animal kingdom. More recently, however, considerable doubt has been cast on this assumption.

The theories of kin selection and reciprocal altruism have led to much productive research in animal behaviour. When applied to human behaviour, however, they have generated much more controversy. Wilson's Sociobiology, for example, unleashed a torrent of criticism when it was published in 1975. Although he dedicated only a short final chapter of the book to human behaviour, the ensuing debate focused almost entirely on the possibility of applying sociobiological tools to humans. Social scientists, in particular, objected to such biological explanations on the grounds that they did not do justice to the rich cultural variability of human behaviour (see instinct).

After the initial backlash against sociobiology in the late 1970s, attempts to apply theories such as those of Hamilton and Trivers to human behaviour regained popularity during the 1990s. The second generation of sociobiologists, who are much more circumspect in avoiding some of the brash pronouncements of the 1970s, go under the name of ‘evolutionary psychologists’. Evolutionary psychology, while in many ways the heir of sociobiology, differs in stressing the importance of the mental mechanisms that mediate selective pressures and behaviour. It is thus more mentalist than sociobiology, and draws on the explanatory tools of cognitive science, such as the use of the language of information processing to describe the mind.

However, unlike cognitive scientists of a more classical bent, evolutionary psychologists reject the idea of a central ‘executive’ within the mind, arguing instead that co-ordinated behaviour emerges from a collection of psychological mechanisms, none of which is ‘in control’. These ‘mental modules’ are thought to be designed by natural selection to solve adaptive problems that were recurrently faced by our ancestors. For example, it is has been hypothesized that there is a module for detecting cheats, another for recognizing faces, and so on.

Like sociobiology, evolutionary psychology has attracted more than its fair share of critics. Some of these attack evolutionary psychology for allegedly excessive speculation, while others have ethical and political objections. Evolutionary psychologists reject both kinds of criticism. The debate goes on.

Dylan Evans

Bibliography

Pinker, S. (1997). How the mind works. Penguin, Harmondsworth.
Wilson, E. O. (1975). Sociobiology: the new synthesis. Harvard University Press, Cambridge, MA.


See also evolution, human; genetics, human.

Sociobiology

views updated May 08 2018

Sociobiology

Sociobiology is the study of the biological basis of social behavior using evolutionary principles. The term was coined by a prominent entomologist E. O. Wilson in his book Sociobiology: The New Synthesis (1975). Wilson pointed out that just as physical characteristics such as beak length and fur color could be subject to natural selection, so too could aspects of social behavior.

The field of sociobiology was part of a broad conceptual shift during the late 1960s and throughout the 1970s. Sociobiology looked closely at the nature of interactions between individuals, replacing a cooperative view of social behavior with the idea that more often, from an evolutionary perspective, individuals should behave in their own self-interest. It was one of several fields that emphasized the genetic basis of behavior in all animals, including humans. In doing so, sociobiology shed light on a number of important aspects of animal behavior, including the evolution of altruism, the occurrence of infanticide and sibling rivalry, parental care, and social and mating systems. The extension of some aspects of sociobiology to humans initiated a controversy, which continues today.

Altruism

Wilson's original focus was on the insects, such as ants, bees, and wasps, a group that commonly contains species that are eusocial. Eusocial species typically live in large highly cooperative groups or colonies, with reproduction limited to a very few members. Why would individual worker bees defend a colony from intruders, feed offspring that belonged to others, and forgo their own reproduction?

Such altruistic or helping behavior puzzled biologists. If natural selection works on behavior just as it works on other traits, why should individuals expend energy or time helping others survive or reproduce when that effort may reduce their own chances of reproduction? In 1964, William Hamilton developed the idea that individuals help their relatives because relatives share genes. Just as genes may be passed on by direct reproduction (producing offspring yourself), "your" genes can be passed on by increasing the reproduction of close relatives. In the social insects, cooperative behaviors associated with eusociality make evolutionary sense because these species have an unusual system of genetic relatedness, making colony members very closely related.

Competition and Cooperation

An evolutionary approach has shed light on other puzzling aspects of behavior. Infanticide or infant killing by males in social monkeys is now believed to be a strategy used by males to speed up female receptivity and prevent females from spending energy on offspring fathered by competing males. Using an evolutionary approach, even close relatives can have conflicts of interest. Natural selection is expected to favor offspring that compete with each other for food (sibling rivalry). Parents should care for offspring, but offspring may demand more attention and energy than parents are willing to give. Parents, after all, must balance the amount of time and energy they devote to any single offspring with demands of other offspring and potential future offspring.

Sociobiology has addressed broad questions concerning the social systems or kinds of groups in which species are found. For example, if groups of certain sizes have a greater likelihood of detecting predators, then they should be favored by natural selection. This may explain herding and flocking. An evolutionary approach to the study of mating systems has highlighted potential conflict of interest between males and females. Females produce few eggs, while males make many sperm. Because of this, females may be more selective in their choice of mates. In each of these cases, the field of sociobiology and an evolutionary approach to behavior led to insights that otherwise would have been missed.

Human Applications

The last chapters of Wilson's book extended the study of sociobiology to humans. Although not the core of his text, this final chapter generated heated controversy over the nature of human social behavior and, in particular, the role of genes versus environment in determining human behavior. Some scientists considered Wilson's ideas dangerous. Genetically determined behavior seems to leave little room for free will, and downplayed the importance of the social and physical environment within which individuals grow and develop.

Since the publication of Wilson's book, more evidence has emerged that aspects of behavior have a genetic basis. With the increasing evidence from genetic and inheritance studies, however, comes an appreciation of the critically important role of the environment. Biologists now appreciate that the environment works together with genes in complex ways to affect behavior.

see also Behavior, Genetic Basis of; Evolution; Field Studies in Animal Behavior; Mating Systems; Sexual Selection; Social Behavior

Diane K. Angell

Bibliography

Hamilton, W. D. "The Genetical Theory of Social Behavior: I and II." Journal of Theoretical Biology 7 (1964): 152.

Wilson, E. O. Sociobiology: The New Synthesis. Cambridge, MA: Belknap Press, 1975.

Sociobiology

views updated May 14 2018

Sociobiology

Sociobiology, also called behavioral ecology, is the study of the evolution of social behavior in all organisms, including human beings. The highly complex behaviors of individual animals become even more intricate when interactions among groups of animals are considered. Animal behavior within groups is known as social behavior. Sociobiology asks about the evolutionary advantages contributed by social behavior and describes a biological basis for such behavior. It is theory that uses biology and genetics to explain why people (and animals) behave the way they do.

Sociobiology is a relatively new science. In the 1970s, Edward O. Wilson, now a distinguished professor of biology at Harvard University, pioneered the subject. In his ground-breaking and controversial book, Sociobiology: The New Synthesis, Dr. Wilson introduced for the first time the idea that behavior is likely the product of an interaction between an individuals genetic makeup and the environment (or culture in the case of human beings). Wilsons new ideas rekindled the debate of Nature vs. Nurture, wherein nature refers to genes and nurture refers to environment.

Sociobiology is often subdivided into three categories: narrow, broad, and pop sociobiology. Narrow sociobiology studies the function of specific behaviors, primarily in non-human animals. Broad sociobiology examines the biological basis and evolution of general social behavior. Pop sociobiology is concerned specifically with the evolution of human social behavior.

Sociobiologists focus on reproductive behaviors because reproduction is the mechanism by which genes are passed on to future generations. It is believed that behavior, physically grounded in an individuals genome (or genes), can be acted upon by natural selection. Natural selection exerts its influence based upon the fitness of an organism. Individuals that are fit are better suited (genetically) to their environment and therefore reproduce more successfully. An organism that is fit has more offspring than an individual that is unfit. Also, fitness requires that the resulting offspring must survive long enough to themselves reproduce. Because sociobiologists believe that social behavior is genetically based, they also believe that behavior is heritable and can therefore contribute to (or detract from) an individuals fitness. Examples of the kinds of reproductive interactions in which sociobiologists are interested include courtship, mating systems like monogamy (staying with one mate), polygamy (maintaining more than one female mate), and polyandry (maintaining more than one male mate), and the ability to attract a mate (called sexual selection).

Sociobiology also examines behavior that indirectly contributes to reproduction. An example is the theory of optimal foraging which explains how animals use the least amount of energy to get the maximum amount of food. Another example is altruistic behavior (altruism means selfless). Dominance hierarchies, territoriality, ritualistic (or symbolic) behavior, communication (transmitting information to others through displays), and instinct versus learning are also topics interpreted by sociobiology.

Sociobiology applied to human behavior involves the idea that the human brain evolved to encourage social behaviors that increase reproductive fitness. For example, the capacity for learning in human beings is a powerful characteristic. It allows people to teach their relatives (or others) important life skills that are passed-down from generation to generation. However, the ability to learn is also a variable trait. That is, not every person learns as quickly or as well as every other person. A sociobiologist would explain that individuals who learn faster and more easily have increased fitness. Another example is smiling. The act of smiling in response to pleasurable experiences is a universal social behavior among people. Smiling is observed in every culture. Furthermore, smiling is an example of an instinct that is modified by experience. Therefore, because the behavior is instinctual, it has a genetic and inheritable basis. Because it is altered by experience, the behavior is socially relevant. Sociobiologists might speculate, then, that since smiling is a visual cue to other individuals that you are pleased, people who tend to smile more easily are more likely to attract a suitable mate, and are therefore more fit.

The discipline of sociobiology is riddled with debate, principally because it attempts to not only explain the behavior of animals but also of human beings. More dangerously, it tries to describe human nature. The idea that human behavior is subject to genetic control has been used in the past to justify racism, sexism, and class injustices. In this respect, sociobiology is similar to Social Darwinism. For this reason, sociobiology remains a controversial discipline. Further criticisms include the observation that sociobiology contains an inappropriate amount of anthropomorphism (giving human characteristics to animals) and it excessively generalizes from individuals to whole groups of organisms.

Sociobiology

views updated May 29 2018

Sociobiology

Sociobiology, also called behavioral ecology , is the study of the evolution of social behavior in all organisms, including human beings. The highly complex behaviors of individual animals become even more intricate when interactions among groups of animals are considered. Animal behavior within groups is known as social behavior. Sociobiology asks about the evolutionary advantages contributed by social behavior and describes a biological basis for such behavior. It is theory that uses biology and genetics to explain why people (and animals) behave the way they do.

Sociobiology is a relatively new science. In the 1970s, Edward O. Wilson, now a distinguished professor of biology at Harvard University, pioneered the subject. In his ground-breaking and controversial book, Sociobiology: The New Synthesis, Dr. Wilson introduced for the first time the idea that behavior is likely the product of an interaction between an individual's genetic makeup and the environment (or culture in the case of human beings). Wilson's new ideas rekindled the debate of "Nature vs. Nurture," wherein nature refers to genes and nurture refers to environment.

Sociobiology is often subdivided into three categories: narrow, broad, and pop sociobiology. Narrow sociobiology studies the function of specific behaviors, primarily in non-human animals. Broad sociobiology examines the biological basis and evolution of general social behavior. Pop sociobiology is concerned specifically with the evolution of human social behavior.

Sociobiologists focus on reproductive behaviors because reproduction is the mechanism by which genes are passed on to future generations. It is believed that behavior, physically grounded in an individual's genome (or genes), can be acted upon by natural selection . Natural selection exerts its influence based upon the fitness of an organism . Individuals that are fit are better suited (genetically) to their environment and therefore reproduce more successfully. An organism that is fit has more offspring than an individual that is unfit. Also, fitness requires that the resulting offspring must survive long enough to themselves reproduce. Because sociobiologists believe that social behavior is genetically based, they also believe that behavior is heritable and can therefore contribute to (or detract from) an individual's fitness. Examples of the kinds of reproductive interactions in which sociobiologists are interested include courtship , mating systems like monogamy (staying with one mate), polygamy (maintaining more than one female mate), and polyandry (maintaining more than one male mate), and the ability to attract a mate (called sexual selection.)

Sociobiology also examines behavior that indirectly contributes to reproduction. An example is the theory of optimal foraging which explains how animals use the least amount of energy to get the maximum amount of food. Another example is altruistic behavior (altruism means selfless). Dominance hierarchies, territoriality , ritualistic (or symbolic) behavior, communication (transmitting information to others through displays), and instinct versus learning are also topics interpreted by sociobiology.

Sociobiology applied to human behavior involves the idea that the human brain evolved to encourage social behaviors that increase reproductive fitness. For example, the capacity for learning in human beings is a powerful characteristic. It allows people to teach their relatives (or others) important life skills that are passed-down from generation to generation. However, the ability to learn is also a variable trait. That is, not every person learns as quickly or as well as every other person. A sociobiologist would explain that individuals who learn faster and more easily have increased fitness. Another example is smiling. The act of smiling in response to pleasurable experiences is a universal social behavior among people. Smiling is observed in every culture. Furthermore, smiling is an example of an instinct that is modified by experience. Therefore, because the behavior is instinctual, it has a genetic and inheritable basis. Because it is altered by experience, the behavior is socially relevant. Sociobiologists might speculate, then, that since smiling is a visual cue to other individuals that you are pleased, people who tend to smile more easily are more likely to attract a suitable mate, and are therefore more fit.

The discipline of sociobiology is also riddled with debate, principally because it attempts to not only explain the behavior of animals but also of human beings. More dangerously, it tries to describe "human nature." The idea that human behavior is subject to genetic control has been used in the past to justify racism, sexism, and class injustices. In this respect, sociobiology is similar to Social Darwinism. For this reason, sociobiology remains a controversial discipline. Further criticisms include the observation that sociobiology contains an inappropriate amount of anthropomorphism (giving human characteristics to animals) and it excessively generalizes from individuals to whole groups of organisms.

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