In relation to two measures of the mobility involved in the migration histories of individuals now resident in the Otmoor villages of Oxfordshire, selectivity for components of the Wechsler Adult Intelligence Scale is clearly demonstrated. However, this selectivity is reconsidered in the light of other covariates of mobility, where these also relate to IQ, for example, some measures of temporal and socioeconomic variation. When correction is made for these, the frequency of highly significant correlations is greatly reduced, suggesting that much of the selectivity operates within the associations between mobility, IQ, and the confounding temporal and socioeconomic variables. There remains, even after removal of the effects of age, class and occupation-type, a pattern of significant association between some components of verbal IQ and the measures of mobility.