A collection of traits consisting of competitiveness, urgency, high achievement, and irritability.

In the 1970s, psychologists started investigating possible links between personality and health. Initial research seemed to indicate that persons with a type A Personality were at higher risk for coronary heart disease—a medical condition that consists of a narrowing of the blood vessels that supply blood to the heart. Type A people are achievement oriented, irritable, impatient with delays, and seem to be always in a hurry. The association between heart disease and type A behaviors was evident, even when other risk factors such as smoking, obesity, or family history were ruled out. In...