The idea that “parents don’t matter”—shorthand for the view that how parents treat their children has no effect on the kids’ behavior, values, achievements and other outcomes—just won’t go away. I can hardly believe it’s been more than 10 years since I wrote about the controversial claim that only genes and peers shape children; once parents contribute an egg or sperm, asserted the book The Nurture Assumption (now out in a revised paperback edition), they have no effect on how their kids turn out.

So I was struck by what’s being called “the largest meta-analysis ever conducted on the association between parenting styles and delinquency.” The meta-analysis, in the Journal of Abnormal Child Psychology, looked at 161 published and unpublished studies on the question, and found that how well parents monitored their children, whether they expressed rejection or hostility, and a number of other factors indeed had an effect.

What’s particularly interesting is the size of the effect. An association can be statistically significant (unlikely to be due to chance) without being practically significant; that is, there can be true cause-and-effect, but a tiny effect. Not so in this case. Rewarding kids for good behavior had an effect size of .11, for instance; not huge, but not tiny (it means that 11% of the difference between kids’ levels of delinquency is due to whether their parents rewarded them for good behavior, something that reduces delinquency). Being authoritative also reduced delinquency, again with an effect size of .11, while being authoritarian increased delinquency, with an effect size of .12. Put the two together and being authoritarian (dictatorial, controlling) as opposed to authoritative (firm, consistent, setting limits, but with love and kindness) accounts for a swing of .23. Physical punishment and verbal aggression also were associated with more delinquency.

The “parents don’t matter” school might argue that little delinquents-to-be bring out the worst in parents, who turn authoritarian. It is the kids’ innate tendencies that cause later delinquency, according to this argument, not how parents behave. The problem with this claim is the many studies showing that whether you are an authoritarian or an authoritative parent “is most often determined before your first kid is even born, and is highly dependent upon your own experience of discipline . . . and your general political/personality orientation,” as clinical psychologist Nestor Lopez-Duran wrote.

In the last 10 years scientists have made significant progress in understanding the interaction between parenting style and the innate, genetic predispositions of children. As I wrote last August, the interaction between genes and environment means that some children will not respond to particular parenting behaviors the way the textbooks say. (My favorite examples were breast feeding and learning from mistakes.) But to extrapolate from that and claim that parents have no effect on how their kids turn out is simply bizarre.