Biological aspects of a high socio-economic group II. IQ Components and Social Mobility

Abstract

Data are presented on the verbal and performance (non-verbal) IQs of a sample of university scientists, their surviving fathers and male sibs. Although mean IQs differ between scientific disciplines the disciplines do not differentially attract scientists from particular socio-economic classes. The verbal IQs of both the scientists and their fathers are positively correlated with socio-economic class but only in the fathers' sample is the performance IQ/class correlation significant. The variance of both verbal and performance IQs increases from Class I to Class IIIM. The overall estimate of heritability for the verbal IQ is higher than that for the performance IQ. Verbal and performance IQs are related to the distance the scientists have moved on the socio-economic scale. The effects of social mobility on the genetic and environmental components of the verbal and performance IQ phenotypic variances are discussed.