Page 285 - The Social Animal

Human Aggression 267

had just felt. The researchers found that the participants were unable
to retaliate exactly in kind, although they tried very hard to do so.
Every time one partner felt the pressure, he “retaliated” with consid-
erably greater force—thinking he was responding with the same
force as he had received. In this way, the game that began with an ex-
change of soft touches quickly escalated into severe and painful pres-
sure. The researchers concluded that the escalation of pain is “a
natural by-product of neural processing.” It helps explain why two
boys who start out exchanging punches on the arm as a game soon
find themselves in a furious fistfight, and why conflicts between na-
tions frequently escalate. Each side justifies what they do as merely
evening the score.

Causes of Aggression

As we have seen, one major cause of violence—in addition to obvi-
ous causes like intergroup hatred, revenge, or war—is violence itself.
When a person commits an act of aggression, especially with a force
that exceeds what the victim may have done to elicit it, this sets up
cognitive and motivational forces aimed at justifying that aggression,
which open the door to increased aggression. Let us look at some of
the other major causes of aggression.

Neurological and Chemical Causes There is an area in the
core of the brain called the amygdala, which is associated with ag-
gressive behaviors in human beings, as well as in the lower animals.
When that area is electrically stimulated, docile organisms become
violent; similarly, when neural activity in that area is blocked, violent
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organisms become docile. But it should be noted that there is flex-
ibility here also: The impact of neural mechanisms can be modified
by social factors, even in subhumans. For example, if a male monkey
is in the presence of other, less dominant monkeys, he will indeed at-
tack the other monkeys when the amygdala is stimulated. But if the
amygdala is stimulated while the monkey is in the presence of more
dominant monkeys, he will not attack but will run away instead.

Testosterone Certain chemicals have been shown to influence ag-
gression. For example, the injection of testosterone, a male sex hor-
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mone, will increase aggression in animals. Among human beings,