Published online by Cambridge University Press: 31 July 2008
Examination of 150 husband–wife pairs from the Otmoor villages of Oxfordshire for levels of similarity in their performance of seven subtests of the WAIS IQ test showed significant positive correlation in five subtests but not in digit span or digit symbol. In no test was there any relation between level of spouse similarity and length of marriage. Scores were varyingly associated with several factors known to be related to total IQ, such as social class and nature of education. When the effects of these factors on IQ variation were removed statistically most of the spouse similarity disappeared. However there remained a significant residual similarity in vocabulary performance and some suggestion of one in similarities and block design.