SEGREGATION ANALYSIS OF FAMILY DATA FOR 15 TESTS OF COGNITIVE-ABILITY

Segregation analysis of 15 tests of cognitive ability administered to 894 families of European ancestry and 366 families of Japanese ancestry gave evidence for a major gene contributing to performance on three tests of spatial ability in both ethnic groups. There was no evidence of major genes segregating in three other tests of spatial ability, or in tests measuring verbal ability, perceptual speed, or memory. The results supported the hypothesis that superior performance on ETS Hidden Patterns (HP) and Raven's Progressive Matrices (PM) is due in part to an autosomal dominant gene that accounts for 32% of the phenotypic variation in HP and 37% of the variation in PM. Evidence for a sex-limited autosomal dominant gene was found for a modification of the Shepard-Metzler Mental Rotations (MR) test, and 48% of the phenotypic variation in MR could be accounted for by this gene. © 1979 Plenum Publishing Corporation.