Don't know if it would come under the "nurture" column -- it does all seem a bit of a tired debate, except for the fact of popular prejudices -- but last year there was the article about the emergence and transmission of a pacific culture amongst wild baboons: crudely, aggressive males got killed off from eating garbage, and the females apparently managed to impose and sustain (up to the point of writing) a pacific culture; couldn't be genetics, because males were imports. Anyway, turned out to be better for everyone -- less stress.
kj khoo