Aggression 573in the reproductive advantage of stronger males and, hence,
that the genes of aggressive males would be more likely to be
reproduced in specific environments (Daly & Wilson, 1985).
However, if we imagine early humans as existing in hunter-
gatherer groups, it seems clear that cooperative behavior
within the group would also contribute to survival. Even
when the sacrifices involved in such cooperation might result
in a disadvantage for a particular individual and his or her
genes, genes related to cooperative behavior might be pre-
served if the cooperation favored kin or others who recipro-
cated the cooperation, or if the penalty of not cooperating was
high, or (in certain conditions) if the group itself benefited
(see D. S. Wilson & Sober, 1994). It seems probable that the
genetics favoring cooperative behavior may offset those fa-
voring male in-group aggressiveness. However, this may not
be so when we consider intergroup combat. Thus, it has been
noted that boys evidence more intragroup cooperation than
girls when their group is in competition (Shapira & Madsen,
1974). In his studies on the conflict between Hindus and
Muslims, Kakar (1996) observed that when boys and girls
were asked to construct an “exciting” scene with toys and
dolls identifiable as Hindu or Muslim, the boys constructed
scenes of violence whereas the girls created scenes of family
life. Further, Thompson (1999) has pointed out that group se-
lection may also have favored the selection of aggressive
individuals who are willing to die for their group when it is in
combat.
Freudian Theory
Freud’s psychoanalytic theory is written from a biological
perspective that is based on the older idea of instincts as dri-
ves or needs. The development of his thinking about aggres-
sion is complex and has been described and critiqued by
Fromm (1973). Taken literally, few would agree with Freud’s
conceptualization. However, on a metaphoric level his theory
allows a rather elegant statement of a viable theoretical posi-
tion, best expressed in his letter to Albert Einstein on the
cause of war (Freud, 1933). Working in the manner of evolu-
tionary biologists today, Freud assumed that early humans
lived in small groups. He postulated that these groups were
initially dominated by the compelling aggression of the
strongest male. This dominance could eventually be over-
come by an aggressive union of weaker males. However,
such a union had to be maintained by the growth of law and
feelings of unity. As Freud (1933, p. 276) put it, “Here, I be-
lieve we have all the essentials: violence overcome by the
transference of power to a larger unity, which is held together
by emotional ties between its members.” As Freud surveyed
history he was not encouraged by what he saw. Although ag-
gression within groups is contained by laws that are enforced
by group union, there is no way to contain aggression be-
tween groups. Some propose the ideal of a union between
groups, but a mere ideal is not sufficient to overcome the ag-
gressive drive of independent groups, and powerful groups
are unwilling to grant sufficient power to a superordinate
body.
In spite of the apparent cogency of the previous argu-
ments, it should be noted that the consensus of contemporary
social scientists is that there is no instinctual press for war
per se. Thus, the group gathered at Seville to examine the
problem declared, “It is scientifically incorrect when people
say that war cannot be ended because it is part of human na-
ture” (UNESCO, 1991, p. 10). The reasoning behind such a
statement is well explicated by Fromm (1973). He pointed out
that war, like slavery, is a human institution. Early hunter-
gatherer groups had no reason to engage in warfare because
there were no goods to plunder. Far from being an aspect of
“primitive” man, warfare develops along with the develop-
ment of civilization. Agriculture and animal husbandry lead
to surpluses and the development of specializations and hier-
archies of power that then become involved in the conquest of
other peoples. Fromm pointed out that there were and still are
peaceful peoples, as well as evidence for a relatively high de-
gree of civilization in a number of matrilocal societies that
existed before warfare began. Of course, these facts do not
preclude a possible instinctive base for the in-group biases
that are so prevalent whenever groups must share resources.
Culture interfaces with a biological base for both cooperation
and violence. Although chimpanzees show extensive cooper-
ative behavior, Blanchard and Blanchard (2000) pointed out
that they also form raiding parties and that this aggressiveness
is inhibited when they are afraid.Conflict TheoriesRather than focus on aggression as the response of individu-
als, we may examine the role it plays in the relations between
people, as a way of wining conflicts, establishing dominance,
or managing impression. This more sociological approach
may be linked to both emotion and biology. Regarding emo-
tion, I proposed that anger is best regarded as a response to a
challenge to what a person asserts ought to exist (de Rivera,
1977, 1981). I argued that when persons become angry, they
are attempting to remove a challenge in a way that is analo-
gous to an animal defending territory. Learned aggressive
responses are recruited to serve this end.
Considering aggression as an aspect of conflict is close to
the biological perspective in that it considers the function of
aggression in a specific cultural environment. In game theory
the choice of a competitive or mistrustful, rather than cooper-
ative, strategy may be regarded as involving aggression in the