Robert Sapolsky, one of my big heroes (and not an alpha baboon). Some links follow, but apply his work to the New Scientist article dn22071 July 2012 issue 2875 : Inequality: Why egalitarian societies died out
"We cannot assume that because inequality exists, it is somehow beneficial. Equality - or inequality - is a cultural choice..."
"[...] inequality might exacerbate selection on an individual level for high fertility, competition, aggression, social climbing and other selfish traits."
And maybe -- alpha baboons?