Stability of type A behavior during adolescence, young adulthood, and adulthood.

The stability of Type A behavior was studied in 1737 randomly selected adolescents and young adults. The method used was the AFMS questionnaire, which is based on the Matthews Youth Test for Health and a Swedish version of the Jenkins Activity Survey. Results showed that in males Type A behavior remained at the same degree of stability during adolescence, later adolescence, young adulthood, and adulthood. In girls, Type A behavior showed no stability during adolescence, a high stability during young adulthood, and a slightly lower degree of stability in adulthood.