Assessing type a behavior in 8-year-olds: exploring the overlap between the constructs of type a behavior and hyperactivity.

This study attempted to examine, by using behavioral observations, the overlap found between Type A behavior, as measured by the Matthews Youth Test for Health (MYTH) questionnaire, and measures of hyperactivity in children. The sample consisted of 91 children (46 boys and 45 girls) between the ages of 8 and 9 who were part of a longitudinal study in Uppsala, Sweden. Behavioral observations of Type A behavior and various questionnaire data were used. The behaviorally observed Type A behavior correlated significantly with MYTH Type A behavior, whereas only the MYTH Type A behavior correlated with hyperactivity measured by questionnaires. The results indicated that behavioral observations make it possible to measure Type A behavior as distinct from hyperactivity, implying that the MYTH is too indiscriminate a measure of Type A behavior. This has implications for future measurement and perhaps conceptualization of Type A behavior in children, and thereby also for studying the developmental aspects of Type A behavior.