a1 Department of Psychology, Bedford College and Department of Psychiatry, St Mary's Hospital, University of London
a2 Department of Physical Anthropology, University of Cambridge
The children in the cohort followed by the National Child Development Study were tested for cognitive ability at the age of eleven, and the influence of a number of biological and social variables was sought on the results of tests of reading, mathematics, verbal and non-verbal abilities. Reading relates strongly to social class, birth order and parental age, suggesting strong social influences upon it, but it is also related to height and acquired myopia, suggesting biological influences. Mathematics ability relates to social class and parental age, but not to birth order, but its relationship with height, birthweight and maternal smoking suggests biological effects. Verbal ability and non-verbal ability have relatively few correlates apart from sex and region. It appears that different cognitive abilities show different relationships to social, biological and personal variables.
(Received June 14 1982)