To examine trends to upward social mobility among a specially selected group of people with above average intelligence. Attitudinal/Behavioural Questions Reasons for joining Mensa, whether membership of Mensa raised occupational ambitions, job preference. Questionnaires were also completed by respondent's immediately older and immediately younger sibling. Background Variables Age, sex, marital status, number of children, whether father still alive (if dead: respondent's age at death), position in family, size of family. Occupation (respondent, parents and siblings-mother's occupation before marriage), years of part-time education, highest qualification, word score, gross income.