joseph henrich at harvard university, welcome to hardtalk. it's good to be with you. in the middle of a heated debate about human evolution. now i'm used to thinking about evolution in terms of genetics, darwin's survival of the fittest. you seem to put your focus not so much on biology, much more on cultural conditioning, nurture. am i right? yeah. i mean, one of the unique things about our species is that more than any other species, we're dependent on acquiring large bodies of information from those around us, from the societies we grow up in. and in fact, our brains have evolved to be able to take in and learn how to process information. so our motivations, preferences, emotions, heuristics, all of these things we can acquire in order to adapt to the cultural technologies and languages and institutions that we have to confront in the world, so we're very much a cultural species. right. and you have written a book which has caused many waves. now there's an acronym at the centre of it — weird — which stands for western, educated, industrialised, rich and democratic