Parents evolved to invest more resources in daughters who chose mates with few resources. This unequal investment was in the parents’ best interests, because a daughter with an unsupportive partner would profit more from extra help than her more fortunate sisters (the principle of diminishing returns on investment). By helping their needier daughters, parents maximized their total number of surviving grandchildren. But this unequal investment created an incentive for daughters to “exploit” their parents’ generosity by choosing a partner who was less supportive. A daughter who was less picky than her sisters would accept a less helpful partner, but since her parents picked up the slack she ended up with … Continue reading Piet van den Berg