In the early 1970s, studies were conducted to investigate the behavioral patterns of individuals with coronary artery disease, resulting in the identification of two distinct personality types associated with such conditions. These personality types were characterized by specific behavioral traits.
During that period, it was postulated that a specific behavioral pattern, referred to as Type A, exhibited a heightened susceptibility to stress-related ailments, including hypertension (high blood pressure). Type A personalities were described as individuals who constantly felt pressured to multitask, possessed a competitive nature, and displayed self-critical tendencies. Moreover, they were characterized by impatience and a tendency to become easily irritated by others. In contrast, individuals with Type B personalities were noted to be more composed and relaxed in their demeanor.