Assortative mating for IQ: a multivariate approach

Abstract

SummaryThis paper examines the similarity between husbands and wives at the IQ subtest level, using seven tests from the Wechsler Adult Intelligence Scale. There was some evidence for sex differences; husbands scored higher than their wives on three of the subtests. After logarithmic transformation of some subtests the data were shown to be consistent with multivariate normality. A simplified covariance matrix was produced. Principal component analysis revealed an underlying general ability factor but there was no simple division into verbal and into performance components as would be expected from the IQ test structure. Canonical correlation analysis indicated that there were highly variable contributions to spousal associations. The major contributors were, in decreasing order of importance, due to similarities, vocabulary, digit symbol and block design tests. One subtest, comprehension, made no overt contribution.