"Like Yanomamö villages, chimpanzee communities are kinship groups based on aggregates of closely related males and unrelated females who have emigrated from other kinship groups... Like Yanomamö war, chimpanzee lethal raiding takes place when a subgroup of males...deliberately invades the recognised territory of a neighbouring community... Do they suggest to us that chimpanzee violence is linked to human war? Clearly they do. The appetite for engagement, the excited assembly of a war party, the stealthy raid, the discovery of an enemy and the quick estimation of odds, the gang-kill, and the escape are the common elements that make intercommunity violence possible for both."