Of six studies designed to link scores on the Cook and Medley Ho scale with health, three have reported positive results and three negative. Some of the inconsistencies in the findings are explained by differences among Type A assessment devices and the populations studied. The Ho scale, on which "Type A" designates a high score, measures anger-proneness, resentment, mistrust of others, and cynical hostility. According to the correlational model, Type A negative expectations and antagonistic behavior, reinforced by high conflict and low support interpersonal relations, translates physiologically into chronic anger, vigilance, stress, and thus CHD. Future research should identify situational characteristics that may elicit physiological differences between high and low scores on the Ho scale and reassess the Ho scale itself, recognizing the possibility that not all Ho scale components are related to health. 1 figure, 57 references.