DOMINANCE

For students of animal behavior, dominance refers to the phenomenon by which individuals of a social species organize themselves with regard to access to resources. Although some social species appear to be egalitarian in many respects, close observations reveal differential access among individuals in nearly all cases, especially when resources are in short supply. These resources may include food, nest sites, mates, or any other considerations that have consequences for evolutionary success, or fitness; a dominance hierarchy is one of the most common patterns whereby access to these resources is established.

Dominance Hierarchies and Relationships

Although dominance relationships have in the past been seen as a species characteristic in themselves, they most importantly reflect differences in size, aggressiveness, and/or motivation among individuals, with these differences generating, in turn, a hierarchy of access to fitness-enhancing opportunities. It also appears to be beneficial to individuals to recognize their competitive relationship with respect to others, because without such recognition considerable time and energy might be wasted re-establishing priority, not to mention risking injury if a confrontation results in actual fighting. A signal characteristic of dominance hierarchies is that despite their aggressive underpinnings, animal societies characterized by rigid dominance relationships tend to experience relatively little actual fighting.

Most specialists maintain that—as with other biological phenomenon—there are no ethical implications of animal dominance relationships per se. While human observers may be inclined to deplore the unfairness whereby some individuals achieve disproportionate access to resources while others are comparatively excluded, dominance relationships, by definition, are not egalitarian. Indeed, during the late-nineteenth and early-twentieth centuries, when social Darwinism was especially influential, dominance relationships among human beings were considered admirable, as a working out of natural law. In the early twenty-first century, biologists acknowledge that dominance relationships among animals do indeed reflect the working out of natural tendencies and inclinations, as do predator-prey relationships, or the patterns of energy flow among different levels of natural communities. Just as neither eagles nor decomposing bacteria are good or bad, the same is true of dominance hierarchies. They are part of natural life, and as such, ethically neutral.

From an evolutionary perspective, dominance relationships among individuals develop because individuals are selected to maximize their fitness, their success in projecting copies of their genes into the future. Natural selection rewards those who succeed in doing so, and, in certain cases, this success is achieved by establishing one's self in a clearly defined situation of social superiority over others.

This is not to say that dominance relationships develop by some sort of intentional decision process on the part of the animals themselves, in which the latter get together and agree to establish a hierarchy. Rather, individuals who are somewhat larger, more aggressive, smarter, or who may have enjoyed such advantages in the past, simply assert themselves and, by virtue of that circumstance, succeed in gaining priority. Natural selection, in turn, supports those who achieve this success insofar as priority to food, mates, and nesting sites, among other things, correlates positively with ultimate reproductive success. Gene combinations that lead to success in such competition are favored in succeeding generations.

In some cases—barnyard chickens are the classic example—individuals end up establishing a pecking order whereby individual 1 dominates individual 2 and all those below, individual 2 dominates individual 3 and all those below, with that pattern continuing. However, dominance relationships are not always linear, nor are they always transitive: In many territorial species, for example, individual 1 may dominate individual 2, and individual 2 dominates individual 3, but individual 3 may dominate individual 1! In others—harem-keeping or polygynous species, such as elk, for example—there may be a single dominant individual (the dominant bull), who is clearly number one, with a less clear hierarchy among the remaining subordinate males.

Dominance relationships among animals depend upon an often tacit acknowledgment of the existing situation, on the part of dominants and subordinates alike. Thus once a dominance relationship is established, it is typically unnecessary for the various participants to fight—or even, in most cases, to engage in elaborate threat and subordination behavior—in order to maintain the pattern. When a dominance pattern is well established, individuals promptly respond to their mutual relationships by recognizing each other as individuals. (Indeed, this rapid, tacit response can be taken as powerful evidence of the participants' capacity to recognize individuals in the first place.)

Traditionally, dominance hierarchies have been seen as relatively immutable. More recent studies, however, have shown that they are not. Even though hierarchical relationships among animals tend to be resistant to change, they are subject to modification, as when a dominant male harem-keeper among langur monkeys is overthrown by one of the previously subordinate bachelors. Similarly, dominance hierarchies among female animals commonly vary as a function of hormonal and reproductive state: Breeding females and those in estrous often experience a temporary increase in their dominance status.

Correlation to Human Dominance Patterns

There is considerable variation in the nature of dominance relationships among different animal species, even some that are closely related. Chimpanzee social behavior, for instance, is generally oriented along lines of male dominance whereas the dominance system of bonobos (formerly known as pygmy chimpanzees) is primarily structured by the interactions of females. This, in turn, leads to question as to which animal system—if any—is most appropriate for understanding social dominance among human beings. Nonetheless biologists as well as increasing numbers of social scientists believe that in some complex way the biological nature of human beings underlies the nature of human politics just as that of other species underlies their pattern of social interactions.

Status signaling has also received considerable research attention. Although it seems legitimate to distinguish between physical characteristics (such as elaborate crests, ruffles, and antlers) used to achieve success in sexual selection by generating greater attractiveness to members of the opposite sex, such traits often also contribute to success in same-sex competition, and thus, with regard to dominance relationships. Would-be competitors are themselves more fit if they respond appropriately to indicators of probable physical or even mental superiority rather then subject themselves to possible injury or time wastage finding out who is successful relative to whom. Additionally it is probably adaptive for potential mates to employ the same traits that are used to establish and maintain same-sex dominance relationships as signals that generate success in between-sex courtship. This is because such traits—if genuinely connected to health and vitality—would lead to more successful offspring and hence be appropriate signals for an individual of one sex to employ in choosing a potential mate, and also because any offspring of such a union, insofar as they possessed these characteristics, would likely to be attractive to the next generation of choosers.

Among human beings dominance is a function of many things, including physical characteristics, intellectual qualities, and the control of material resources. Social dominance typically goes beyond the merely physical ability to intimidate a would-be rival, and carries with it signifiers of social rank such as clothing, make of automobile, speech patterns, and self-confidence. As in the case of animals, it is difficult —and perhaps impossible—to separate intrasexual from intersexual aspects of dominance. There is evidence that mastery of technology contributes to social dominance, and moreover, that the pursuit of technological and scientific success is generated, albeit unconsciously, by an underlying pursuit of social dominance (which itself is pursued because of its ultimate connection with reproductive success). The fact that such connections and motivations—if they exist—are not consciously pursued, does not make them any less genuine. At the same time, even as biologists are agreed that dominance and the pursuit of dominance is natural, there is no evidence that it is either ethically privileged or, by contrast, to be disparaged.

DAVID P. BARASH

SEE ALSO Ethology;Selfish Genes;Social Darwinism.

BIBLIOGRAPHY

Ardrey, Robert. (1971). The Social Contract. New York: Doubleday. An early and rather speculative attempt to examine the role of dominance hierarchies in human beings.

De Waal, Frans B. M., and Peter Tyack, eds. (2003). Animal Social Complexity: Intelligence, Culture, and Individualized Societies. Cambridge, MA: Harvard University Press. A technical work that examines the inter-relationships of animal social behavior—including but not limited to dominance relationships—and aspects of culture and intelligence.

Masters, Roger D. (1989). The Nature of Politics. New Haven, CT: Yale University Press. A political scientist considers the likely role of biological considerations in influencing complex patterns of human behavior.

Schein, Martin W. (1975). Social Hierarchies and Dominance. New York: Dowden, Hutchinson & Ross. A technical consideration of how dominance hierarchies form among animals and how they can be measured.

Smuts, Barbara. (1999). Sex and Friendship in Baboons. Cambridge, MA: Harvard University Press. A primatologist examines prosocial behavior among free-living baboons, showing that dominance relationships allow for benevolent interactions.