A Natural History of Human Morality offers the most detailed account to date of the evolution of Human moral psychology.
The first step occurred as ecological.
There were two key evolutionary steps, each founded on a new way that individuals could act together as a plural agent "we".
Based on extensive experimental data comparing great apes and Human children, Michael Tomasello reconstructs how early humans gradually became an ultra-cooperative and, eventually, a moral species.
A Natural History of Human Morality offers the most detailed account to date of the evolution of Human moral psychology