Type A behavior in preschool children: construct validation evidence for the MYTH.

This study examined the construct validity of 1 measure of Type A behavior, the Matthews Youth Test for Health (MYTH), with preschool-age children. Convergent and discriminant validity evidence was obtained based on teacher ratings, intelligence test scores, and reaction time in a visual discrimination task. As predicted, Type A behavior was related to ratings of aggression and impatience, but not to intelligence. An experimental analysis was conducted of the conjoint effect of 2 situational variables, time constraint and incentive, on reaction time. Children classified as Type A or Type B on the basis of the MYTH participated in a visual discrimination task either with or without the presence of a time constraint and an incentive. As predicted, the reaction times of Type B children who worked without a time limit and an incentive were significantly longer than both groups of Type A children and the Type B children who worked with a time limit and an incentive. In summary, support was obtained for the construct validity of the MYTH when used with preschool-age children.