Coalitions - especially male coalitions - and intergroup rivalries are a cross-culturally universal feature of human societies ranging from hunter-gatherer societies to complex, post-industrial societies. Expressions of coalitionalism include states, politics, war, racism, ethnic and religious conflict, civil war, castes, gang rivalries, male social clubs, competitive team sports, video games, and war re-enactment (Alexander 1987; Keegan 1994; Sidanius and Pratto 2001; Tiger 1969; Tooby and Cosmides 1988; Tooby, Cosmides, and Price 2006).
Our core claim is that theoretical considerations and a growing body of empirical evidence support the view that the human mind was equipped by evolution with a rich, multicomponent coalitional psychology. This psychology consists of a set of species-typical neurocomputational programs designed by natural selection to regulate within-coalition cooperation and between-coalition conflict in what, under ancestral conditions, was a fitness promoting way (Tooby and Cosmides 1988; Kurzban, Tooby, and Cosmides 2001; Price, Cosmides, and Tooby 2002; Tooby, Cosmides, and Price 2006).
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These selection pressures built our coalitional psychology, which expresses itself in war, politics, group psychology, and morality. The evolutionary dynamics of war, coalitional behavior, and moral interactions are worth studying because the past world of conflict and cooperation is reflected in the present architecture of the human mind.