The self-administered, 14-item Bortner questionnaire was used to characterize the Type A behaviour of the members of a group of families selected from 3 general practice registers. The questionnaire was found to be easy to complete and showed no systematic variation on repeat administration. The rank order of the 14 items was similar in the men, women and children of the study (and in a sample of Belgian men where the Bortner questionnaire had been validated against other measures of Type A behaviour). There was a social class gradient among the men but not among the women or children, and there was no correlation of this behaviour characteristic between parents and their children. This simple questionnaire may thus be an acceptable way of characterizing Type A behaviour which, it is suggested, might develop during adult life in response to occupational experiences.