Page 274 - The Social Animal

256 The Social Animal

powerful death instinct, Thanatos, an instinctual drive toward
death, leading to aggressive actions. About the death instinct, Freud
wrote: “It is at work in every living being and is striving to bring it
to ruin and to reduce life to its original condition of inanimate mat-
ter.” Freud believed that aggressive energy must come out somehow,
lest it continue to build up and produce illness. Freud’s notion can
best be characterized as a hydraulic theory. The analogy is one of
water pressure building up in a container: Unless aggression is al-
lowed to drain off, it will produce some sort of explosion. According
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to Freud, society performs an essential function in regulating this in-
stinct and in helping people to sublimate it—that is, to turn the de-
structive energy into acceptable or useful behavior.

Aggression Among the Lower Animals Research on the
instinctiveness of human aggression is provocative but inconclusive
because it is impossible to conduct a definitive experiment. Accord-
ingly, scientists have turned to experiments with nonhuman species
to gain additional insight into the extent to which aggression may be
hardwired. To take one example, consider the common belief about
cats and rats. Most people assume that cats will instinctively stalk
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and kill rats. Nearly half a century ago biologist Zing Yang Kuo at-
tempted to demonstrate that this was a myth. He performed a sim-
ple little experiment: He raised a kitten in the same cage with a rat.
Not only did the cat refrain from attacking the rat, but the two be-
came close companions. Moreover, when given the opportunity, the
cat refused either to chase or to kill other rats; thus the benign be-
havior was not confined to this particular buddy but generalized to
rats the cat had never met.
Although this experiment is charming, it fails to prove that ag-
gressive behavior is not instinctive; it merely demonstrates that the
aggressive instinct can be inhibited by early experience. What if an
organism grows up without any contact with other organisms? Will
it or won’t it show aggressive tendencies? It turns out that rats raised
in isolation (i.e., without any experience in fighting other rats) will
attack a fellow rat when one is introduced into the cage; moreover,
the isolated rats use the same pattern of threat and attack that expe-
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rienced rats use. So even though aggressive behavior can be modi-
fied by experience (as shown by Kuo’s experiment), aggression
apparently does not need to be learned.