Saturday, June 21, 2008

Holding back for no reason

Casual observation suggests that many parents are holding their children back a grade to improve their academic performance later on. The theory is that for some kids, not being behind in the pack can help them stay with the pack and assist learning. The problem is that studies of whether this actually helps or not are plagued by the likely fact that parents who choose to hold kids back might be doing so for reasons beyond simple learning; e.g., for other socialisation or maturity factors that confound later measurement of performance.

A new study looks at a Norwegian 'experiment' that takes parental choice out of the equation. In Norway, children start school based on the year they turn 7. So if you are born on December 31 you are a year ahead of a child born the next day. Effectively the same age but the New Year's Baby has been randomly red-shirted. The authors then look at the measured IQ of children entering the military at age 18 (apparently most people) and relate it to these date issues.

It turns out the age you start school matters little for the IQ test score at age 18. But those who start school late have reduced earnings up until about age 30.

The upshot of this is that there are no reasons to hold kids back or time births for some age advantage in class. It is not clear whether it goes the other way -- that is, we don't know if accelerating kids might help. My guess is that more caution in terms of moving around school entry away from standard practice should be the rule for parents rather than erring on the side of having your child be the oldest in the class.