Type A behavior and cardiovascular responsivity in preschoolers.

Type A behavior was investigated in preschool children in relation to cardiovascular reactivity. One hundred forty-four children from 3 1/2 to 6 1/2 years of age were categorized by their teachers according to the Matthews Youth Test for Health as Type A, Mixed, or Type B. The children's pulse, pulse rate variability, and blood pressure were then measured at rest and during a challenging situation. Analysis of covariance indicated that Type A children showed a significantly greater systolic rise to challenge than did Type B children, a finding similar to that of Type A adults, college students, and adolescents.