If you were to try to recall the times that you have been aggressive, you would probably report that many of them occurred when you were angry, in a bad mood, tired, in pain, sick, or frustrated. And you would be right—we are much more likely to aggress when we are experiencing negative emotions. When we are feeling ill, when we get a poor grade on an exam, or when our car doesn’t start—in short, when we are angry and frustrated in general—we are likely to have many unpleasant thoughts and feelings, and these are likely to lead to violent behavior. Aggression is caused in large part by the negative emotions that we experience as a result of the aversive events that occur to us and by our negative thoughts that accompany them (Berkowitz & Heimer, 1989).
One kind of negative affect that increases arousal when we are experiencing it is frustration (Berkowitz, 1989; Dollard, Doob, Miller, Mowrer, & Sears, 1939). Frustration occurs when we feel that we are not obtaining the important goals that we have set for ourselves. We get frustrated when our computer crashes while we are writing an important paper, when we feel that our social relationships are not going well, or when our schoolwork is going poorly. How frustrated we feel is also determined in large part through social comparison. If we can make downward comparisons with important others, in which we see ourselves as doing as well or better than they are, then we are less likely to feel frustrated. But when we are forced to make upward comparisons with others, we may feel frustration. When we receive a poorer grade than our classmates received or when we are paid less than our coworkers, this can be frustrating to us.
Although frustration is an important cause of the negative affect that can lead to aggression, there are other sources as well. In fact, anything that leads to discomfort or negative emotions can increase aggression. Consider pain, for instance. Berkowitz (1993b) reported a study in which participants were made to feel pain by placing their hands in a bucket of ice-cold water, and it was found that this source of pain also increased subsequent aggression. As another example, working in extremely high temperatures is also known to increase aggression—when we are hot, we are more aggressive. Griffit and Veitch (1971) had students complete questionnaires either in rooms in which the heat was at a normal temperature or in rooms in which the temperature was over 32 degrees Celsius (90 degrees Fahrenheit). The students in the latter condition expressed significantly more hostility.
Hotter temperatures are associated with higher levels of aggression (Figure 9.7) and violence (Anderson, Anderson, Dorr, DeNeve, & Flanagan, 2000). Hotter regions generally have higher violent crime rates than cooler regions, and violent crime is greater on hot days than it is on cooler days, and during hotter years than during cooler years (Bushman, Wang, & Anderson, 2005). Even the number of baseball batters hit by pitches is higher when the temperature at the game is higher (Reifman, Larrick, & Fein, 1991). Researchers who study the relationship between heat and aggression have proposed that global warming is likely to produce even more violence (Anderson & Delisi, 2011).
Research Focus: The Effects of Provocation and Fear of Death on Aggression
McGregor et al. (1998) demonstrated that people who have been provoked by others may be particularly aggressive if they are also experiencing negative emotions about the fear of their own
death. The participants in the study had been selected, on the basis of prior reporting, to have either politically liberal or politically conservative views. When they arrived at the lab
they were asked to write a short paragraph describing their opinion of national politics. In addition, half of the participants (the mortality salience condition) were asked to “briefly
describe the emotions that the thought of your own death arouses in you” and to “Jot down as specifically as you can, what you think will happen to you as you physically die, and once you are
physically dead.” Participants in the exam control condition also thought about a negative event, but not one associated with a fear of death. They were instructed to “Please briefly describe
the emotions that the thought of your next important exam arouses in you’’ and to “Jot down as specifically as you can, what you think will happen to you as you physically take your next
exam, and once you are physically taking your next exam.” Then the participants read an essay that had supposedly just been written by another person in the study. (The other person did not
exist, but the participants didn’t know this until the end of the experiment.) The essay that the participants read had been prepared by the experimenters to condemn politically liberal views
or to condemn politically conservative views. Thus one-half of the participants were provoked by the other person by reading a statement that strongly conflicted with their own political
beliefs, whereas the other half read an essay that supported their beliefs (liberal or conservative). At this point, the participants moved on to what they thought was a completely separate
study in which they were to be tasting and giving their impression of some foods. Furthermore, they were told that it was necessary for the participants in the research study to administer
the food samples to each other. The participants then found out that the food they were going to be sampling was spicy hot sauce and that they were going to be administering the sauce to the
same person whose essay they had just read! In addition, the participants read some information about the other person that indicated that the other person very much disliked eating spicy
food. Participants were given a taste of the hot sauce (which was very hot) and then instructed to place a quantity of it into a cup for the other person to sample. Furthermore, they were
told that the other person had to eat all the sauce.
As you can see in Figure 9.8, this research provides another example of how negative feelings can lead us to be aggressive after we have been provoked. The threatening essay had little effect on the participants in the exam control condition. On the other hand, the participants who were both provoked by the other person and who had also been reminded of their own death administered significantly more aggression than did the participants in the other three conditions.
A threat to one’s worldview increased aggression but only for participants who had been thinking about their own death. Data are from McGregor et al. (1998).
Just as negative feelings can increase aggression, positive affect can reduce it. In one study (Baron & Ball, 1974), participants were first provoked by an experimental confederate. Then the participants were, according to random assignment, shown either funny cartoons or neutral pictures. When the participants were given an opportunity to retaliate by giving shocks as part of an experiment on learning, those who had seen the positive cartoons gave fewer shocks than those who had seen the neutral pictures.
It seems that feeling good about ourselves, or feeling good about others, is incompatible with anger and aggression. You can see that this is in essence the flip side of the results we discussed in Helping and Altruism, regarding altruism: just as feeling bad leads us to aggress, feeling good makes us more likely to help and less likely to hurt others. This makes perfect sense, of course, since emotions are signals regarding the threat level around us. When we feel good, we feel safe and do not think that we need to aggress.
Of course, negative emotions do not always lead to aggression toward the source of our frustration. If we receive a bad grade from our teacher or a ticket from a police officer, it is not likely that we will directly aggress against him or her. Rather, we may displace our aggression onto others, and particularly toward others who seem similar to the source of our frustration (Miller, Pedersen, Earleywine, & Pollock, 2003). Displaced aggression occurs when negative emotions caused by one person trigger aggression toward a different person. A recent meta-analysis has found clear evidence that people who are provoked but are unable to retaliate against the person who provoked them are more aggressive toward an innocent other person, and particularly toward people who are similar in appearance to the true source of the provocation, in comparison to those who were not previously provoked (Marcus-Newhall, Pedersen, Carlson, & Miller, 2000).
It is clear that negative affect increases aggression. And you will recall that emotions that are accompanied by high arousal are more intense than those that have only low levels of arousal. Thus it would be expected that aggression is more likely to occur when we are more highly aroused, and indeed this is the case. For instance, in his important research on arousal, Dolf Zillmann found that many types of stimuli that create arousal, including riding on a bicycle, listening to an erotic story, and experiencing loud noises, tend to increase both arousal as well as aggression (Zillman, Hoyt, & Day, 1974; Zillman, Katcher, & Milavsky, 1972). Arousal probably has its effects on aggression in part through the misattribution of emotion. If we are experiencing arousal that was actually caused by a loud noise or by any other cause, we might misattribute that arousal as anger toward someone who has recently frustrated or provoked us.