Mothers and fathers contribute different things to the lives of their offspring. Mothers, for example, tend to be more attuned to the moods and feelings of young children especially; fathers excel at discipline and at pushing children to give their best effort. On this topic, though, I think it can help to move beyond the sociological research and ask people: are you really comfortable asserting that a child suffers no misfortune by being motherless? Or by being fatherless? Of course there will always be children who grow up under sub-optimal circumstances, often for reasons beyond anyone’s control. That’s not a justification for cementing sub-optimal circumstances as a new norm.