But that generally suggests that cultural and social influences were not major factors in the deep past. Here's a recent cross-cultural study which does suggest the power of social and cultural factors.
http://rady.ucsd.edu/faculty/directory/gneezy/pub/docs/gender-differences-competition.pdf
And it's worth noting that the tribes in the study are far from our advanced industrial society (which is rather divorced from our evolutionary past). Love the quotes in the paper:
"We are sick of playing the roles of breeding bulls and baby-sitters."
A Khasi man (Ahmed, 1994)
ABE:
Aye, and it was fun reading the sturm-und-drang raised by certain types to such a situation.
"Men treat us like donkeys."
A Maasai woman (Hodgson, 2001)
1994 and 2001 isn't the deep past! I'm not someone who believes less materially advanced cultures around the world are any different from us in the west fundamentally, they've been around to think about things for just as long as we have.

