Discuss evolutionary explanations of group displays of aggression The adaptive and functional benefits of aggressive behaviour must outweigh the possible costs in order for it to be favourable. Acquisition of status and access to mates are some of the primary motivators of aggression in non-human animals, but there are many theories as to why humans have adapted. One of them is the Power-Threat Hypothesis, which represents the fear of a political power being in the hands of a minority group.
If a minority group poses a hreat to a majority group, then they must display aggression in order to maintain their dominance over the minority group. Real life events that support this theory are lynch mobs, in which the vast majority of victims were African American males. Tolnay and Beck found that some Of the reasons for the lynching of black people were for them trying to vote and voting for the wrong party. This is adaptive because they are trying to maintain their dominant status over the minority group by displaying aggression in the form of lynchings.
However, Clark studied lynch mobs in different countries and found that the main victims in some of those countries were Afro-Brazilians. They were not considered to pose a threat to the dominance of the majority community, and so this contradicts the hypothesis, as the fear of the minority was not the major factor in these lynchings. There is also support that lynching is made more likely through the process of de-individuation. Mullen found that as the size of the lynch mob increased, it led to a breakdown in normal self-regulation processes which led to an increase in the level of iolence against the victim.
Another theory behind aggression is sexual selection, because in some cultures there are fewer females than males. In order for males to attract a female they must compete with each other, and one of the ways they do this is by taking part in war. Male warriors in traditional societies tend to have more sexual partners and more children, suggesting a direct reproductive benefit (Chagnon). Research has provided support for the importance of aggressive displays in determining the sexual attractiveness of male warriors.
Palmer and Tilley found that male youth street gang members have more sexual partners than ordinary young males. Leunissen and Van Vugt also found that military men have greater sexual appeal, but only if they have been observed showing bravery in combat. However, this explanation fails to explain the levels of cruelty that are often found in human wars yet not among non-human species, such as torturing or mutilating their opponents. This has no adaptive advantage to humans and so contradicts the evolutionary theory of aggression.