Foldesi’s research supports the concept of xenophobia. Foldesi (1996) found that violent displays among a small core of Hungarian football crowds led to an increase in violent and racist outbursts by spectators.
However, conflicting research by Marsh suggests football violence may not be an act of naturally selected xenophobia, but more an organised behaviour to gain peer acceptance within the group.
Another limitation of sport studies is it only accounts for aggressive behaviour at sports events and doesn’t explain aggressive behaviour elsewhere.
However, research into religious rituals provides an alternative explanation. Aggressive behaviour can be self-inflicted, for example as part of an initiation rite or religious ritual. Sosis believes that engaging in a painful religious rituals has been favoured by natural selection as it signals commitment to membership of a group. Therefore, the costs of religious rituals which is pain and injury promote and maintain religious cooperation within groups and to deter people from joining other groups which is why they show group aggression.
Research conducted by Sosis & Belster support the concept of religious rituals. They found that religious groups impose twice as many costly rituals on their members as non-religious groups, and that the number of costly rituals was positively correlated with the lifespan of the group. This supports the claim that religions that require the greatest displays of commitment produce the most committed members and so last the longest.
Likewise, supporting research was conducted by Chen who found that as the Indonesian financial crisis in the 1990s worsened, Muslim families devoted far more of their remaining money to religious observance, suggesting that in times of crisis the higher costs have the reward of benefitting the neediest members of the community. This supports the idea that in close-knit communities, corporation confers benefits to group members. However, this research only supports religious aggression and no other reasons to aggression.
An alternative approach of group aggression is through Lynch Mobs. Patterson claims that there was major social transition in the USA at the time following the collapse of slavery, and entire white communities felt at risk. When groups feel at risk, their survival becomes dominant, and the in-group cooperates defensively at the same time as behaving offensively towards any outgroup.
Supporting research by Myrdal argues that white people in the USA were scared of black people and turned to lynch law as a means of social control. Which supports the claims of lynch laws being a means of group aggression.
A limitation of research into lynch mobs is that it’s outdated. This is because there is high equality between races and the explanations from lynch mobs cannot be used today as the same issues of racism doesn’t occur today. However, Clark (2006) conducted research recently and found a negative correlation between lynching’s in Brazil and the number of Afro-Brazilians in the community supporting group displays of aggression in other races.
Overall, the evolutionary approach on group aggression is deterministic. If aggression is caused by our genes, biochemistry or abnormality of our brain structure, then we have no choice for how we behave. But not all groups of humans are not always aggressive, and crowds do not always lead to aggression. If aggressive behaviour was only determined then why isn’t everyone showing aggression?
Furthermore, the approach mainly focuses on the nature of aggression rather than the nurture. There is plenty of evidence for the biology and social psychological influences but doesn’t consider things in the environment which might anger a group leading to aggression.
Explanations of human aggression tend to focus on an industrialised Western point of view, and in so doing fail to consider the individuality and differences of other cultures. When another culture is judged in terms of the researcher’s own culture, it creates an imposed etic.
Lastly, the approach is reductionistic. No single theory seems to adequately account for group displays of human aggression. Sport and xenophobia, religion, and lynch mobs have all been suggested as causes, however many other theories may also contribute. Examples of other factors that could lead to group aggression include biological factors and personality dispositions. Deindividuation could also account for group behaviours, for example the extreme behaviours of lynch mobs could be explained as individuals losing their individual sense of responsibility and instead adopting the behaviour of the group. In deindividuation, individuals would never behave that way outside of a group setting but in a crowd they will.
In conclusion, there is strong evidence for why aggression occurs in groups. However, all explanations fail to consider other approaches such as social factors. Bandura’s social learning theory suggests that aggression is caused not only by inherited factors but also environmental factors such as reproduction which is copying (aggressive) behaviour you have witnessed. This therefore means the evolutionary theory is not purely the cause of group displays of aggression.