Page 289 - The Social Animal

Human Aggression 271

unrest might occur with greater frequency in the heat of summer
than in the fall, winter, or spring. Was this actually true or mere spec-
ulation? It turns out to be true. In a systematic analysis of distur-
bances occurring in 79 cities between 1967 and 1971, J. Merrill
51
Carlsmith and Craig Anderson found that riots were far more
likely to occur during hot days than during cold days. Similarly, in a
more recent study, Anderson and his colleagues have shown that, the
hotter it is on a given day, the greater the likelihood that people will
commit violent crimes. Moreover, they also showed that heat did not
increase the incidence of burglary and other property crimes—thus
strengthening the linkage between heat and violence (not simply
general criminality). 52
But, as you know by now, we have to be cautious about interpret-
ing events that take place in natural settings. For example, the scien-
tist in you might be tempted to ask whether increases in aggression
are due to the temperature itself or merely to the fact that more peo-
ple are apt to be outside (getting in one another’s way!) on hot days
than on cool or rainy days. So how might we determine that it’s the
heat itself that caused the aggression and not merely the greater op-
portunity for contact? We can bring the phenomenon into the labo-
ratory. This is remarkably easy to do. For example, in one such
53
experiment, William Griffitt and Roberta Veitch simply adminis-
tered a test to students, some of whom took it in a room with nor-
mal temperature, while others took it in a room where the
temperature was allowed to soar to 90°F. The students in the hot
room not only reported feeling more aggressive but also expressed
more hostility to a stranger whom they were asked to describe and
rate. Additional evidence from the natural world helps bolster our
belief in the cause of this phenomenon. For example, it has been
shown that in major league baseball games, significantly more bat-
ters are hit by pitched balls when the temperature is above 90° than
54
when it is below 90°. And in the desert city of Phoenix, Arizona,
drivers without air-conditioned cars are more likely to honk their
horns in traffic jams than are drivers with air-conditioned cars. 55

Frustration and Aggression As we have seen, aggression can
be prompted by any unpleasant or aversive situation, such as anger,
pain, excessive high temperatures, and the like. Of all these aversive
situations, the major instigator of aggression is frustration. Imagine