who came up with type a and b personality
Type A and Type B personality theory Type A personality behavior was first described as a potential risk factor for heart disease in the 1950s by cardiologists Meyer Friedman and Ray Rosenman. They discovered that their patients were wearing out the arms and upholstery on the chairs in the waiting room [3] After an eight-and-a-half-year-long study of healthy men between the ages of 35 and 59, Friedman and Rosenman estimated that Type A behavior doubles the risk of coronary heart disease in otherwise healthy individuals.[4] The individuals enrolled in this study were followed well beyond the original time frame of the study. Participants were asked to fill out a questionnaire, that asked questions like "Do you feel guilty if you use spare time to relax?" and "Do you generally move, walk, and eat rapidly?"[5] Subsequent analysis indicated that although Type A personality is associated with the incidence of coronary heart disease, it does not seem to be a risk factor for mortality.[6]