The reasoning for this could be also found in the primal motivations. The male motivation, as you indicated, involved the spreading of his seed widely. While the woman was more involved in nurturing and developmental side of species prolongation. As such they were more social creatures and developed a community sense from which they learned things from each other as to how to better care for their children (and themselves). So they look on each other for ways of improving themselves and their lives. This is also why female relationships are more about emotion and support than male ones. (this is also why women tend to learn things easier than men...but this is a broad generalization (no real pun intended)) Rawnrr