Susan Mayer’s What Money Can’t Buy concludes by tossing out a fun fact I’ve often heard repeated.  (I even repeated it myself once in an exchange with Charles Murray).

Both low income and single parenthood may in fact be correlated with poor outcomes for children because they are proxies for unmeasured parental characteristics.  This suspicion is bolstered by the well-established finding that when single parenthood is a by-product of death rather than divorce or failure to marry, children do about as well as children living with two parents who have comparable incomes. (McLanahan and Sandefur 1994)

So I decided to check out McLanahan and Sandefur (1994), entitled Growing Up With a Single Parent.  Mayer’s claim checks out, but the evidence was thinner than I hoped.  Here’s the key figure:


The behavioral genetic story, of course, is that in modern societies, premature death is usually a random fluke.  As a result, a parent’s premature death doesn’t tell us much about his children’s life outcomes.  Divorce and extramarital births, in contrast, are largely products of parental behavior, which in turn substantially stems from hereditary traits like IQ, conscientiousness, neuroticism, etc. 

As always, other stories are possible.  But given everything else we know about nature and nurture, not very plausible.