“…However, this aggressive violence has generally been in the form of intergroup violence. Studies on intergroup aggression have provided solid findings that show intergroup conflict and aggression have been common across human societies throughout our evolutionary history (McDonald et al, 2012;Pinker, 2011;Hagen, 2008;Bowles, 2012;Walker, 2001;Lambert, 1997). As McDonald et al (2012, p. 670) put it ''conflicts among human groups have occurred throughout our modern history and range from large-scale conflicts, such as wars between countries, terrorism, racial and ethnic discrimination, and conflict among political parties, to relatively small-scale conflicts involving competition, antagonism and aggression among rival sport teams, gangs and high school cliques.''…”