On environmental stressor on aggression is temperature. It has been found that high temperature causes an increase in a person’s level of arousal. High temperature can make a person agitated or irritable, thus when they encounter a situation that causes stress their levels of arousal increase which consequently increases their levels of aggression. Palmarek and Rule (1979) conducted a study in which they asked participants to do tasks in either a high temperature or a comfortable temperature. It was found that greater aggression occurred when there was moderate arousal. When there was low or high arousal, aggressive behaviour was reduced. When the temperatures became exceptionally high, the participants became more interested in finishing the task rather than prolonging the situation with aggressive altercations.
However, a problem is that Anderson and Anderson blamed demand characteristics for the findings observed in Palmarek’s study. This means that the findings may have been influenced by the fact that the study was conducted in a laboratory environment, therefore the participants would not be reacting in the same way as they would if they were in a natural environment. This is problematic as the findings may not be valid as they did not measure what they intended to measure.
In contrast to this, Palmarek’s study is supported by Baron and Bell (1976). They studied how the heat affects the willingness to give electric shocks to another person. They found that the level of aggression increased between 92F and 95F, and any temperature higher than this resulted in a decrease of aggression. The reason for this may be down to the extreme stress caused by the temperature as the participants could not cope with the reactions of the person receiving the shocks in addition to the extreme heat. This supports Palmarek’s study as it gives scientific evidence to back up what has already been found.
However, a negative criticism is that there are thought to be other explanations for the increases found in aggression as temperature rises. An example of this is people are more likely to be outside when it is hot, so therefore more likely to come into contact with others. The fact that they are around many other people may be a contributing factor to their high levels of aggression. This goes against Palmarek’s study as this proposes that there are other variables that influence levels of aggression in a person in high temperatures.
A second environmental stressor on aggression is thought to be overcrowding. It has been argued that emotional arousal can increase as people feel that their personal space is violated and often results in people withdrawing from social contact. Stokols proposed three ways of explaining why overcrowding can lead to aggression. The first theory is called Stimulus overload. This suggests that aggression may occur when the amount of stimulation produced by crowding exceeds our ability to deal with it. Calhouse conducted a study and found that rats became more aggressive as the number living together increased. The aggression got so high that at one point young rats were killed or eaten by others. This shows that rats were responding to stimulus overload caused by the extreme number of other rats living with them.
However, a problem with this study is that it suffers from extrapolation. This means that the study used only rats as it’s participants. This is a problem as this means that the findings cannot be generalised to humans due to the fact that humans and rats do not act in the same way, therefore it would be difficult to generalise the findings. The second theory is Behavioural constraint. This theory suggests that aggression depends on what we want to do and whether crowing stops us from doing it. Green found that heavily congested traffic routes are more likely to provoke an aggressive response in drivers. This shows evidence as the traffic jam would prevent them from doing what they need to do; travel.
A negative criticism of this is that Freedman concluded that crowding in itself had neither good nor bad effects. He said that it serves to intensify the individual’s typical reactions to the situation, whether they are positive or negative. This view completely contradicts the behavioural constraint theory, therefore serves as a valid argument against it. The third theory is the Ecological model which proposes that insufficient resources such as food and privacy may result from crowding, which would lead to aggression. Loo found that children became more aggressive as the number of people in their nursery increased, yet it decreased once the density got past a certain point. This shows that the children were competing for adult attention and use of toys.
However, a problem is that from the evidence it seems that crowding is related to aggression, but the relationship is complex as the effects of crowding vary with social context, for example a crowded party may produce different effects to a political party of a major football game. This shows that the ecological model is restricted in what it can explain. A final general criticism is that laboratory studies in the past have produced mixed results. An example of this is Freedman et al’s study in which he found that crowding increased aggression in all male groups but the opposite occurred in all female groups. This is problematic because it is apparent that the effects of crowding differ between the two genders, therefore the findings from one experiment can not generalise to everybody.