Citation

Brant AM, Munakata Y, Boomsma DI, Defries JC, Haworth CM, Keller MC, Martin NG, McGue MK, Petrill SA, Plomin R, Wadsworth SJ, Wright MJ, Hewitt JK. Psychol. Sci. 2013; 24(8): 1487-1495.

Affiliation

1Department of Psychology, The Pennsylvania State University.

Copyright

(Copyright © 2013, Association for Psychological Science, Publisher John Wiley and Sons)

DOI

10.1177/0956797612473119

PMID

23818653

Abstract

: IQ predicts many measures of life success, as well as trajectories of brain development. Prolonged cortical thickening observed in individuals with high IQ might reflect an extended period of synaptogenesis and high environmental sensitivity or plasticity. We tested this hypothesis by examining the timing of changes in the magnitude of genetic and environmental influences on IQ as a function of IQ score. We found that individuals with high IQ show high environmental influence on IQ into adolescence (resembling younger children), whereas individuals with low IQ show high heritability of IQ in adolescence (resembling adults), a pattern consistent with an extended sensitive period for intellectual development in more-intelligent individuals. The pattern held across a cross-sectional sample of almost 11,000 twin pairs and a longitudinal sample of twins, biological siblings, and adoptive siblings.

Language: en