A survey of a Cambridge suburb: familial resemblances and IQ components.

Abstract

SummaryThis study presents parent–offspring and sibling resemblances for verbal and visuospatial IQ components and total IQ scores in both non-manual and manual social groups. Offspring on mid parent regression coefficients provided upper limits to phenotypic IQ similarity. There were no significant differences in regressions between social groups.The sex linked hypothesis for spatial ability was examined but neither parent–offspring nor sibling correlations were in the order predicted by the hypothesis.