There's a new paper out which models human behavioral ecology, Dynamics of Alliance Formation and the Egalitarian Revolution. Anthropology.net has a good review, so I'll just point you there. I was going to read this paper, and a few others on models of human group dynamics...but lately, I've been wondering, aren't there enough models now??? It seems like there is a large sample space of models which can generate a set of testable predictions. Perhaps it is time to catch up on data and experiment and hold off on more model generation? I'll probably keep reading these papers...but of late I've started to get the feeling that without more data the task of understanding human behavioral history is Sisyphean.