The purpose of this study was to investigate the degree of stability and change in abilities and personality in individuals and sub-groups. To examine the effects of sex and social class differences on development trends of these cognitive abilities and personality growth. (Questionnaires were also administered when children were aged 7 and 8, but these data are not currently deposited in the Archive.) Attitudinal/Behavioural Questions Aged five (interview with mother) Effects on the child and his/her general behaviour in the following circumstances: change in the family; away with family; child-minded; school. Health of mother, difficulties with child - feeding, sleeping, toilet training. Child: habits; fears; play; emotional characteristics; independence; interest/response to e.g. nakedness, God, death. Background Variables Age, sex, health, school.