The “nurture assumption” is basically the idea that parents really, really, matter in affecting variation in individual outcomes in their children. Judith Rich Harris famously wrote a book length critique, The Nurture Assumption: Why Children Turn Out the Way They Do, which was published in 1999. I’ve argued that the Steven Pinker’s The Blank Slate is important in large part because it introduced a broader audience to Harris’ conclusions. Though the pattern that she observes, that most variation in outcomes for individuals does not seem to be accounted for by shared environment, that component that is under parental control, is a robust behavior genetic finding it runs against deep human intuitions. This is one domain where political Left and Right share the same sympathies, though the details differ. Many cultural conservatives in the United States impute to parents an almost alchemical power to shape the nature of their children through inculcation. Similarly, cultural liberals attribute the same sort of power to society broadly construed.
If you’ve been reading me for 13+ years you know all this. As a parent these last four years I’ve had to struggle with the nurture assumption myself. For psychological and social reasons the impulse is strong within us. Recently Brian Boutwell has been doing the Lord’s work, so to speak, in Quillette, reintroducing these ideas to a general audience. Now he and I have co-authored the latest installment, Heritability and why Parents (but not Parenting) Matter. I invite you to check it out!