Boehm's model conceptualizes a common ancestor to humans, chimpanzees, and bonobos at several million years B.P., followed by a model of prehistoric foragers at 25,000-50,000 B.P. based on ethnographic data from twentieth-century hunters and gatherers. By putting processes of complex communication into the picture, we can refine Boehm's model considerably by filling in significant scenarios for humans beginning at perhaps 2 million years ago. These include a suite of features that include constraints on sexual behaviour, a rudimentary division of labour, (...) the gendering of morality, socialized control over junior males, increased group size, increased home range size, the reduction of bullying behaviour, and a reverse dominance hierarchy that promotes egalitarianism among fully adult males. Boehm's model emphasizes the last two of these, but it is consistent with the others as well. Cultural or proto-cultural elaboration of beliefs and associated practices is the symbolic dimension of morality and is an important component of human evolution. Boehm's model is extremely important for outlining socio-political mechanisms and concomitants in the formation of adult male egalitarian groups, and, in the process, identifying a key element in the evolution of human morality. (shrink)