Matt Ridely argues something like this, characterising it as trade within a group, and perhaps it began with the hunter/gatherer division of labour between the

Matt Ridely argues something like this, characterising it as trade within a group, and perhaps it began with the hunter/gatherer division of labour between the sexes. https://wikipedia.org/wiki/The_Rational_Optimist https://wikipedia.org/wiki/The_Rational_Optimist Can you elaborate on your sources?