Sarah McLanahan reported from her continuing study of "fragile families" at the Furstenberg conference. She had some interesting new things to say about the effects of family instability - especially boyfriends passing in and out of the household.
One major effect is that instability increases the mother's mental health problems, especially depression and anxiety.
Another major finding is that instability hurts boys more than girls.
This led me to a thought about why girls out-perform boys in school, when the reverse used to be true: girls may be passing boys because instability hurts boys more, and family instability is increasing.