A cumulative process of selective adaptation to the new distribution of employments will set in, especially if the habitat or the fauna with which the group is in contact is such as to call for a considerable exercise of the sturdier virtues.

The habitual pursuit of large game requires more of the manly qualities of massiveness, agility, and ferocity, and it can therefore scarcely fail to hasten and widen the differentiation of functions between the sexes.

And so soon as the group comes into hostile contact with other groups, the divergence of function will take on the developed form of a distinction between exploit and industry.
In such a predatory group of hunters it comes to be the able-bodied men's office to fight and hunt.

The women do what other work there is to do--other members who are unfit for man's work being for this purpose classed with women.

But the men's hunting and fighting are both of the same general character.