Except, it turns out that a lot of the things that get attention in these “optimize your baby” strategies do not actually seem to boost child outcomes. I’ve done a lot of research on this recently, and the overwhelming sense you get is that much of these investments do not matter.

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Take the Teach Your Baby to Read system, which promises that you can do just that, starting around 3 months. It uses an expensive system of flash cards and DVDs to (ostensibly) teach very young children (under 2) to read.

This system relies heavily on video. But studies show that babies do not learn well from video in general. Given this, it is perhaps not surprising that randomized evaluation showed that the system did not confer reading abilities on babies age 9 months to 18 months. The researchers noted that this poor result was measured despite claims by parents that the system was very successful, suggesting that it is easy to trick yourself into thinking your child can read.

We see, similarly, no evidence that Baby Einstein-style videos can teach children to have a larger vocabulary. Playing Mozart in the womb doesn’t confer any benefits either. And when it comes to the age-old (by which I mean, decade-old) upper-middle-class debate over preschool philosophies? There is no evidence that Montessori is better than play-based, or vice versa.

How do we understand these contrasts — where, on the one hand, the first few years are the crucible of success and, on the other, the kind of investments that many of us obsess about do not seem to matter much?

The answer is that we tend to ignore the big picture. The differences we see by demographic groups in the United States — the inequality of outcomes for children from poor and rich backgrounds — are driven by a combination of vast differences in experiences.