The degree of cognitive complexity exhibited in the decision making of Type A individuals was assessed. Cognitive complexity/simplicity was characterized as a heterogeneous construct rather than a unitary trait. Tendencies to perceive ambiguity as threatening, to be imperceptive of subtle differences among stimuli, and to underutilize available information in decision making were considered manifestations of cognitive simplicity. Subjects completed the Jenkins Activity Survey along with three measures of cognitive complexity. As opposed to their Type B counterparts, Type A subjects exhibited cognitive simplicity by making decisons unidimensionally, focusing upon a single stimulus feature while giving relatively little weight to the remaining stimulus dimensions. This style may enhance Type A individuals' sense of control over mastery-threatening situations, but it may also hinder their ability to recognize and then avoid pathogenic situations and behaviors that contribute to risk of heart disease.