Lynch mobs - need for conformity
Out of 4742 documented lynch mobs, nearly 3/4 were on black people! Patterson (1999) argues the collapse of slavery caused a major social transition. The whites feared the blacks (the sub group), therefore group display of aggression caused them to co-operate together and 'antagonise' the 'outsiders'.
Boyd and Richerson (1990) Found that in groups where co-operation thrived, so did mobs. This explains why when a majority group feel threatened, by a minority group they will group and work together to protect their own interests.
Another explanation of lynch mobs in deindividualization. Most lynch mobs occur at night, with a large gorup that is wearing things to protect their identities. These factors reduce self-attention and increase deindividualisation. Mullen looked at 60 lynch mobs and found the larger mobs were the more violent ones.
Lynch mobs - Power threat hypothesis
This suggests that the majority group see's the sub group as a threat and so they discriminate against them (using violence). The lynching is used by the majority group as a threat and message to the sub group. The white's argued the black men were trying to **** white women. But lynching was just used as a sign of power by the whites.
However, social threat is poorly defined. Clark looked at lynch mobs in Brazil and found evidence that contradicted with this hypothesis. There were other factors linked to lynching. In Sao Paulo the percentage of Afro-Brazilians in communities was negatively correctional with incidents of lynch mobs.
Religious rituals - Costly signalling theory
By engaging in painful rituals like self flagellation, it shows your commitment to a group. Religious behaviour promotes co-operation. Zahavi and Zahavi (yes they have the same surname) suggested that these rituals also deter those who intend to join the group to just get benefits, but don't actually have the same beliefs.
Sosis and Bressler found that religious groups tended to impose twice as many costly requirements on their members than non religious groups and the number of costly requirements were positively correlated with the lifespan of the group. Therefore, the group which imposes the greatest display of commitment (usually involving self inflicted pain) produces the most committed members and the longest lasting group.
Religious rituals - Costly signalling theory cont.
This explains success of religion. However, there is a dark side to this understanding as the stronger the intra group, the more conflict it will create with other groups. Roes and Raymond those groups with the strictest practices had the most inter-group conflict.
Gender Bias - Most studies are done on males, but women have been found to initiate and commit extreme acts of violence (but less extreme acts).
Ethical issues (race) - The studies do show that the there is a differences in the level of aggression between racial/religious groups and that some groups are more violent than others.