Re: reciprocal altruism. Given the vast swathe of human prehistory, virtually anything not absurdly complex will be “tried” occasionally. It only takes a small number of people whose brains happen to wired to “tit-for-tat” to get started, and if they out-compete people who don’t cooperate (or people who help everyone regardless of behaviour towards them), the wiring will quickly become universal.
Humans do, as it happens, explicitly copy successful strategies on an individual level. Most animals don’t though, and this has minimal relevance to human niceness, which is almost certainly largely evolutionary.
Re: reciprocal altruism. Given the vast swathe of human prehistory, virtually anything not absurdly complex will be “tried” occasionally. It only takes a small number of people whose brains happen to wired to “tit-for-tat” to get started, and if they out-compete people who don’t cooperate (or people who help everyone regardless of behaviour towards them), the wiring will quickly become universal.
Humans do, as it happens, explicitly copy successful strategies on an individual level. Most animals don’t though, and this has minimal relevance to human niceness, which is almost certainly largely evolutionary.