AGGRESSION

The word aggression comes from the Latin roots ag (before) and gred (to walk or step). Hence to aggress is to step before or in front of someone, to initiate something, commonly an attack. Aggression—whether by a state or an individual—refers to an unprovoked, offensive action against another. It is useful to contrast aggression with violence, which derives from the Latin root vio, which refers to force. Dictionary definitions include "rough, unjust, unwarranted and injurious physical force or treatment," as well as "immoderate vehemence, typically causing injury, pain or gross distortion." It is possible to talk about a violent storm, or an earthquake of exceptional violence, but the term is most often applied to human actions, in which case it generally implies that pain or injury is intentionally inflicted on someone or something.

By contrast aggression is not necessarily hurtful: A person may promote a viewpoint aggressively, for example, which implies initiative, forcefulness and assertiveness, but without injury. It is admirable to conduct an aggressive campaign against cancer, poverty, or illiteracy. One may even seek to aggressively oppose violence. Nonetheless aggression as such is not highly regarded; it, like its frequent concomitant, violence, is typically considered undesirable, at least from the perspective of most ethicists.

Aggression Among Animals

Aggression is widespread among animals, especially those living in social groups. Although it sometimes takes the form of clear, outright violence, aggression is more often subtle, involving intimidation and the displacement of one individual by another, typically in the context of established dominance hierarchies. Early scientific studies of animal behavior emphasized that animal aggression very rarely results in serious injury or death, and that most living things with the capacity of inflicting serious harm on one another have evolved inhibitory mechanisms that prevent them from doing so. As ethological studies have gotten more sophisticated, however, it has become clear that these generalizations were idealized and exaggerated. In fact animals, even members of the same species, do kill one another. There is, however, some truth to the generalization that many living things have evolved behaviors that make lethal aggression less frequent than might otherwise be expected.

Increasingly sophisticated field studies of animal behavior show that animal aggression is not limited to inter-individual events; inter-group aggression has also been documented—for example, between lion prides or chimpanzee groups. Lethal aggression, in these cases, is most likely when the groups in question consist of genetically unrelated individuals, just as within-group aggression is also significantly modulated among close relatives, as predicted by selfish gene theory.

Aggression Among Human Beings

There has been considerable research into the causes of aggression, especially among human beings. Aggression is caused by many different factors; indeed, virtually every scientific specialty has its own take on which factors are especially important. For psychoanalysts, aggression derives largely from innate human destructiveness, what Freud called thanatos, or the death instinct. Although biologists are particularly unconvinced by this approach (it is difficult to imagine a situation for which a death instinct—especially when directed toward one's self—would be selected), there are parallels between this and another instinctivist approach, best articulated by the ethologist Konrad Lorenz (1903–1989). Lorenz hypothesized that aggression has evolved in a variety of circumstances, including spacing and population control, and provides an opportunity for competition within a species, as a result of which the most fit members will emerge to produce the next generation, and also establishes a means whereby the pair bond is strengthened, when, for example, a mated pair demonstrates shared aggression against competitors.

Sociobiology and evolutionary psychology provide updated biological explanations for human and animal aggression, emphasizing the degree to which aggression is adaptive rather than somehow mandated by the genome. This approach focuses on the way particular behavior patterns are maintained and promoted in a population because they contribute to the reproductive success of individuals (and their genes), as opposed to groups or species. For example, the adaptionist evolutionary view of aggression examines such phenomena as ecological competition, male-male competition, and the role of kinship patterns in directing aggressive behavior in particular ways. It also focuses on aggression as a response to circumstances rather than an innate need. Adaptionists do not argue that aggressiveness will emerge despite affirmative constraints. Rather, proponents maintain that living things have the capacity to behave aggressively when such behavior maximizes their fitness, and to behave pacifically when that response is in their best evolutionary interest.

It should be emphasized that predatory behavior—hunting—is different from aggressive behavior. The fact that certain Australopithecines and other prehuman species were evidently meat-eaters does not in itself mean that they were aggressive. Aggressive behavior is most prominent within a species, not between species. Lions, for example, often behave aggressively toward other lions, in which case they make themselves conspicuous and threatening; by contrast, when hunting zebras, lions employ very different behavior patterns, making themselves inconspicuous until the actual attack, and not relying on bluff or other means of aggressive intimidation.

The mainstream view among social scientists is that aggression is almost entirely a response to specific circumstances. So-called frustration theory has been especially influential; it posits that whenever aggressive behavior occurs, there must be frustration, and similarly, whenever frustration occurs, it always produces aggression of some kind. Other psychological approaches focus on the role of social learning, such as conditioning theory in which aggressiveness—by groups as well as individuals—is more likely when such behavior has been positively reinforced, and less likely when negatively reinforced. In short aggression is crucially modified by its consequences.

Social psychologists, by contrast, focus on the degree to which individuals can be socialized to aggressiveness, just as sociologists examine the role of social structures (religion, family, work ethos, mythic traditions) in predisposing toward aggression. Special consideration has been given to matters of ethnic, racial, and religious intolerance. Ironically, although most scientists agree that race has no genuine biological meaning, theories that focus on the importance of stereotyping and of in-group amity, out-group enmity have gained increasing attention.

For anthropologists interested in cross-cultural comparisons of human aggression, a paramount consideration is the extent to which aggression may be functional in acquiring land, access to mates, or status, as well as in regulating population, organizing social relationships within the group, and even influencing the pressure that tribal units place upon agricultural productivity and/or human population or the wild game on which they may depend. The prehistory of human aggressiveness remains shrouded in mystery, although most specialists agree that primitive human groups engaged in substantial violence as well as cannibalism.

For many political scientists, relevant considerations include the role of rational calculations of state benefit and national power. An important underlying assumption is that states behave aggressively when it is in their perceived interest to do so, perhaps because of the prospect of enhancing their influence and power (realpolitik), minimizing potential decrements to it, or enhancing the political viability of national leaders, among other reasons. Approaches run the gamut from mathematical models created by game theoreticians to analyses of historical cycles, matters of national prestige, and economic/resource based considerations.

Aggression and Ethics

Ethical analyses of aggression are nearly as diverse as efforts to explain its occurrence. Although aggression among animals is not susceptible to ethical judgments, human aggression certainly is. Indeed ethical assessments—often negative—may be especially directed toward cases of aggression. Such judgments may be absolute, on the order of philosopher Immanuel Kant's (1724–1804) categorical imperative, which maintains that any act or aggression is acceptable only if it could be reasonably seen to be based on general principles of behavior. However situational ethics typically emphasize that aggression should be evaluated with regard to the conditions in which it occurs. Thus self-defense—whether by an individual or a group—is enshrined in most legal and moral codes, whereas aggression is widely considered to be unacceptable when it occurs without adequate provocation, or preemptively.

The degree to which such ethical judgments are supported or undermined by scientific studies is open to debate. For instance, some believe that scientific knowledge of the biological mechanisms of aggressive behavior demonstrates that cultural moderation, in the form of moral sanctions, is a continuation of nature in nurture. Others argue that the widespread presence of aggression among animals legitimates its presence among humans. In the end, the tensions between these arguments point toward granting moral judgments or values some degree of independence in assessing human behavior, although such judgments will, by necessity, be refined as science advances additional theories to explain the complexities of aggression. Finally, the discussion of whether and to what extent science and technology can be characterized as aggressive activities, although again somewhat independent of scientific research, is furthered by reflection on the scientific study of the phenomena of aggression.

DAVID P. BARASH

SEE ALSO Darwin, Charles;Ethology;Just War;Nature versus Nurture;Sociobiology;Violence.

BIBLIOGRAPHY

Barash, David P. (2001). Understanding Violence. Needham Heights, MA: Allyn & Bacon. Contains many crucial pieces concerning violence, from a variety of disciplines.

Barash, David P., and Charles P. Webel. (2002). Peace and Conflict Studies. Thousand Oaks, CA: Sage Publications. A comprehensive textbook that introduces the field of peace and conflict studies.

Eibl-Eibesfeldt, Irenaus. (1979). The Biology and Peace and War: Men, Animals and Aggression. New York: Viking. Presents traditional ethological ideas concerning aggression, with special attention to human peace and war.

Lorenz, Konrad Z. (2002). On Aggression. New York: Routledge. A readable and only slightly outdated account of the classical ethological approach to animal and human aggression.

Moynihan, Martin H., and Michael H. Robinson. (1998). The Social Regulation of Competition and Aggression in Animals. Washington, DC: Smithsonian Institution Press. A technical compendium of source material concerning causes of, and constraints upon, aggressive behavior in animals.