Four Cracks in the Nurture Edifice
Why sociocultural explanations for sex differences fall short
This is the eleventh excerpt from my forthcoming book, A Billion Years of Sex Differences. You can access the full collection here.
In this installment, I begin tackling the big question: Why are men and women different? If you ask most psychologists, they’ll give you some version of the same answer: Society made them that way. Rigid gender roles. Stereotypes. Differential treatment by parents, teachers, and peers. It’s a tidy story - and a compelling one.
The only problem is that the evidence doesn’t seem to want to play ball. At least four common flaws plague sociocultural explanations for sex differences:
Phantom Causes. Sociocultural explanations often posit causes that don’t exist or that go in the opposite direction to what’s claimed.
Mistaking Chickens for Eggs. Are boys and girls different because they’re treated differently - or are they treated differently because they’re different?
The Second Law of Behaviour Genetics. Twin and adoption studies show that the family home has surprisingly little long-term impact.
The Gender-Equality Paradox. Many sex differences are larger, rather than smaller, in wealthier, more gender-equal nations - the exact opposite of what sociocultural theories predict.
A quick reminder before we dive in: Waterstones UK are offering a 25% pre-order discount on the book. Just use the promo code FEB26 at checkout. The deal ends February 20.
Four Cracks in the Nurture Edifice
I don’t think any reasonable person could deny that the environment helps shape sex differences. That doesn’t necessarily mean, however, that our current crop of sociocultural theories does a good job of explaining how. Certainly, the theories seem plausible. But so do lots of ideas that turn out to be false. Sure enough, when we start digging into the details, we find that many sociocultural explanations suffer one of four main defects.
1. Phantom Causes
In some cases, sociocultural explanations point to causal factors that don’t exist, or that are the reverse of what the explanations claim. For example, contrary to the idea that parental socialization is a major contributor to sex differences, several large meta-analyses – that is, studies that aggregate the results of other studies – suggest that, in important ways, modern Western parents don’t treat their daughters and sons particularly differently. Among other things, parents are just as likely to encourage independence and achievement in daughters as sons, and are no more restrictive of daughters.
Moreover, when parents and others do treat boys and girls differently, it’s often in the opposite direction to that presupposed by the sociocultural theories. Rather than discouraging aggression in girls more than boys, for instance, parents spend more time discouraging it in boys. Why? Because boys engage in more of it!
2. On Chickens and Eggs
Sometimes, the sociocultural theories get their facts straight, but face a chicken-and-egg problem in explaining them. Are boys and girls different because people treat them differently, or do people treat them differently because they’re different? Do women cry more than men because they’ve seen more movies in which women cry, or do movies feature more women who cry because most movies are set in this universe, and in this universe, women tend to cry more? Do stereotypes of the sexes cause sex differences, or do sex differences cause stereotypes of the sexes? Alternatively, does the causal arrow point in both directions in each of these cases?
These are all legitimate possibilities. Most of the time, however, psychologists assume a single direction of causation, and put all their eggs in that one basket. For some reason, almost invariably, they seem to choose the least plausible or least important direction to focus on. To give one example, psychologists often attribute huge causal power to stereotypes, when the best available evidence suggests that, although stereotypes can function as self-fulfilling prophecies, the effects are generally modest, and stereotypes reflect reality more than they shape it. It’s hard to dodge the conclusion that psychology often describes the world the way psychologists would like it to be, rather than the way it is.