Jennifer Roback Morse was almost my colleague – she left the Public Choice Center in 1996, a year before GMU hired me.  She’s a libertarian economist, a blogger, and passionate about the economics of the family.  I’ve only met her once (at a party at Larry Iannaccone‘s house), but you’d think that we’d have a lot in common.  Unfortunately, I walked away from Morse’s Love and Economics: Why the Laissez-Faire Family Doesn’t Work thoroughly perplexed.

My overarching question: How can a 21st-century social scientist publish a book about the family without even mentioning* the possibility that nature, not nurture, accounts for the greater success of kids raised in traditional homes?  In 1960, a scholar might point out that children of divorce, single moms, or working moms do worse, and infer causation.  In 1980, a scholar might tighten up the case by controlling for income, race, and so on.  But by 2001 – the year Love and Economics appeared – genetically informed designs using twins or adoptees were already the gold standard of serious research.  And research using these methods has a strong tendency to find that nature does indeed crush nurture, especially in the long-run.  Contra Morse, the best evidence (see Harris, Pinker, and Segal for starters) shows that as far as kids are concerned, the “laissez-faire family” does indeed work about as well as the competition.

The emotional anchor of Morse’s book is her experience adopting a neglected Romanian orphan.  She movingly describes the awful treatment he endured during his early years, and his need for a full-time mom to get him back on track.  She could easily be right that a “laissez-faire family” wouldn’t have worked for her son.  The twin and adoption studies scholars rely on rarely include severely deprived children, so the standard result that nature dominates nurture in the long-run might not apply. 

But Morse doesn’t just want to carve out an exception for kids like her adopted son.  Instead, she wants to generalize from severely deprived kids to mundane departures from the traditional family like divorce, single motherhood, and moms with full-time jobs.  The data from twin and adoption studies just won’t let her get away with that.

* There’s one entry in the index for genetics, but the entry refers to
the sociobiological argument that men are less likely to abuse their
biological children, not the behavioral genetic point that your
biological children will resemble you in many ways whether or not you
ever meet them.