Saturday, September 17, 2005

Genetics and mathematics (Gq) - Intelligence "in press" article

"In press" articles for the next issue of Intelligence have again been posted. I will try to post FYI posts as I skim the articles.

The following article presents interesting data regarding the "generalist genes" hypothesis of human cognitive abilities/disabilities.

Kovas, Y., Harlaar, N., Petrill, S. A., & Plomin, R. (2005). 'Generalist genes' and mathematics in 7-year-old twins. Intelligence, 33(5), 473-489.

Abstract

  • Mathematics performance at 7 years as assessed by teachers using UK national curriculum criteria has been found to be highly heritable. For almost 3000 pairs of 7-year-old same-sex twins, we used multivariate genetic analysis to investigate the extent to which these genetic effects on mathematics performance overlap with genetic effects on reading and general intelligence (g) as predicted by the 'generalist genes' hypothesis. We found substantial genetic overlap between mathematics and reading (genetic correlation = 0.74) and between mathematics and g (0.67). These findings support the 'generalist genes' hypothesis that most of the genes that contribute to individual differences in mathematics are the same genes that affect reading and g. Nonetheless, the genetic correlations are less than unity and about a third of the genetic variance on mathematics is independent of reading and g, suggesting that there are also some genes whose effects are specific to mathematics..

As stated in the article:
  • A “generalist genes” theory of learning abilities and disabilities has recently been proposed which predicts that most genetic effects for scholastic achievement and cognitive abilities are general rather than specific (Plomin & Kovas, in press). That is, the genes that affect one area of learning, such as mathematics performance, are largely the same genes that affect other abilities, although there are some genetic effects that are specific to each ability.