Measurement of Type A behavior in preschoolers.

The purpose of this study was to investigate the psychometric properties of the Matthews Youth Test of Health (MYTH) and its subscales of Hostility, Competitiveness, Impatience, and Leadership when used with preschoolers. The MYTH was completed by 13 teachers on 155 preschool children in a cross-sectional study and on sub-samples of this original group who were followed during a 2-year longitudinal study. These results were used to investigate internal consistency and test-retest reliability of the MYTH. Construct validity was evaluated by factor analysis as well as by examining the relationship of the MYTH scale and its subscales to cardiovascular reactivity, self-esteem, and locus of control. Construct validity was further assessed by testing for a predicted difference between boys and girls on the MYTH.