IN THE late 1990s the US Department of Education undertook a monumental project called the Early Childhood Longitudinal Study (ECLS). This sought to measure the academic progress of more than 20,000 children from kindergarten through to the fifth grade (ages 5 to 11). The subjects were chosen from across the country to represent an accurate cross-section of American schoolchildren.

The ECLS measured the students’ academic performance and gathered typical survey information about each child: its race, gender, family structure, socioeconomic status, the level of its parents’ education, and so on. But the study went well beyond these basics. It also included interviews with the students’ parents (and teachers and school administrators), posing a long list of questions more intimate than those in the typical government interview: whether the parents spanked their children, and how often; whether they took them to libraries or museums; how much television the children watched.

The result is an incredibly rich set of data — which, if the right questions are asked of it, tells some surprising stories.

So according to these data, does parenting have a clear impact on a child’s academic progress. Did all those Baby Mozart tapes pay off? What about those marathon readings of Goodnight Moon? Was the move to the suburbs worthwhile? Do the kids with PTA [the national Parent Teacher Association] parents do better than the kids whose parents have never heard of the PTA?

The wide-ranging ECLS data offer a number of compelling correlations between a child’s personal circumstances and its school performance. For instance, once all other factors are controlled for, it is clear that students from rural areas tend to do worse than average. Suburban children, meanwhile, are in the middle of the curve, while urban children tend to score higher than average. (It may be that cities attract a more educated workforce and, therefore, parents with smarter children.)

On average, girls show results higher than boys, Asians show results higher than whites, and blacks show results similarly to whites from comparable backgrounds and in comparable schools.

Consider the following list of 16 factors. According to the ECLS data, eight of the factors show a strong correlation — positive or negative — with test scores. The other eight don’t seem to matter. Feel free to guess which are which.

1. The child has highly educated parents.

2. The child’s family is intact.

3. The child’s parents have high socioeconomic status.

4. The child’s parents recently moved into a better neighbourhood.

5. The child’s mother was thirty or older at the time of her first child’s birth.

6. The child’s mother didn’t work between birth and kindergarten.

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