If, instead, our ancestors evolved from lone hunters directly to mixed sex groups with undifferentiated roles and then to villages with gender and other roles, the development of gender specialization could not have proceeded without such bonds and instincts.

In that scenario, there would still be the formation of couples bonding together, but in addition, the males collectively in the group would have bonded together as providers and protectors of their village, and the females would have bonded together as nurturers of their village and for food gathering and preparation.