For all these reasons—costly sperm, the difficulty of having and guarding multiple females, the difficulty of conception, the high likelihood that a gestation may fail, the fact that dependent offspring may do better with paternal care than without—inseminating and running was never such a great strategy. The idea of naturally polygamous males and naturally monogamous females (guys who favored multiple mating over care and gals who wanted the one “right” guy) was cast increasingly in doubt in the decades after Sarah Hrdy’s insights about strategically promiscuous female langurs.
