Genetic Analysis of Cognitive Failures (CFQ): A Study of Dutch Adolescent Twins and Their Parents

A substantial part of the inter-individual variation in everyday cognitive failures in memory, perception and motor control can be attributed to genetic factors. Cognitive failures were assessed with the Cognitive Failures Questionnaire (Broadbent, Cooper, FitzGerald and Parkes, 1982) in a large sample of Dutch adolescent twin pairs and their biological parents. The heritability for CFQ scores was around 50 per cent. There was no association between CFQ scores and age or educational level. Both in the parental generation (aged 46 years on average) and in the o€spring generation (aged 17.7 years on average) women had somewhat higher mean CFQ scores than men. There were no sex di€erences in heritabilities. The part of the variance that could not be attributed to genetic factors was best explained by environmental in ̄uences unique to the individual. There was no evidence for the in ̄uence of shared environment on CFQ scores. CFQ scores of husband and wife were correlated (r ˆ 0.22) and this association was modeled as phenotypic assortment. The correlations between parents and o€spring were somewhat lower than the correlations between dizygotic twins. Under a model with equal heritabilities in parents and o€spring, there was some evidence that the genetic factors that in ̄uence cognitive failures in the two generations are partly di€erent. # 1998 John Wiley & Sons, Ltd.