In short, bigger is better throughout the normal range of birth weight. This remained true even when low birth-weight babies were removed from the analysis. It looks as if birth weight puts you on a trajectory by age 8, and you stay there until at least early adulthood. There's no sense that birth weight gives you an increasing advantage over age. By age 43, in fact, the relationship between bulky birth weight and test scores breaks down.
Bigger babies are no longer smarter adults.
The research adds to the evidence on the lasting benefits of good fetal development. Richards says David Barker, at the University of Southampton, found an association between low birth weight and a range of medical problems in adults, including diabetes and cardiovascular illness. In other words, it's good cocktail conversation, but he wouldn't recommend buying stock in a company that promises to market growth factors to over-eager parents. Since women are already encouraged to have big babes, the practical implications of the study may be limited. Let's put it in context.