Some factors are well-known, e.g., socio-economic status of the parents, and so you’d statistically remove those “usual suspects” first.
In 2007 Duncan and colleagues introduced a new method of analyzing this type of data, and they applied it to six sizable international data sets that followed kids from as early as birth to 3rd grade, focusing especially on reading and math achievement. They concluded that early measures of math and reading, and measures of attention were significant predictors of later math and reading skills, but early social skills were not. Curiously, early math scores predicted later reading scores as well as early reading scores did.
Their conclusions, while not startling, attracted a lot of attention because the new method was deemed quite useful, and because it was applied meticulously to several large-scale datasets.
In 2010, another article was published using the same methodology, but with a startling result.
David Grissmer and his colleagues noted that three of the data sets had early measures of fine motor skills. They found that, after they statistically accounted for all of the factors that Duncan et al had examined, fine motor skills was and additional, strong predictor of student achievement.
I have to note that what the tests called “fine motor skills” strikes me as a bit odd. Cognitive psychologists think of that as being tasks like buttoning a button, or picking something up with tweezers—i.e., requiring precise movements, usually of the fingers. But in these data sets it was tested with tasks like copying simple designs, or drawing a human figure. These are not solely motor tasks.
The fuzziness of exactly what the tasks mean may cloud the interpretation, but it doesn’t cloud the size of the effect—these tasks are a robust predictor of later math and reading achievement.
There’s plenty of speculation as to why this effect might work. Perhaps the measure of “fine motor skills” is really another way of measuring some aspect of attention. Perhaps it’s another way of measuring how well kids can understand and use space. Or the effect may be more direct; it’s commonly thought that the motor and cognitive domains are intertwined, and so practicing motor tasks may aid cognition.
The big question: does this mean that practice of fine motor skills will boost academic achievement? Those studies are ongoing, and I hope to report on the results here before long.
Duncan, G. J., Dowsett, C. J., Claessens, A., Magnuson, K., Huston, A. C.,Klebanov, P., . . . Japel, C. (2007). School readiness and later achievement. Developmental Psychology, 43, 1428–1446.
Grissmer, D., Grimm, K., J., Aiyer, S. M., Murrah, W. M., & Steele, J. S. (2010). Fine Motor Skills and Attention: Primary Developmental Predictors of Later Achievement. Developmental Psychology, 46, 1008-1017.