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]
Gray's biopsychological theory of personality The biopsychological theory of personality is similar to another one of Gray's theories, reinforcement sensitivity theory. The Biopsychological Theory of Personality was created after Gray disagreed with Hans Eysenck's arousal theory that dealt with biological personality traits.[5] Eysenck looked at the ascending reticular activating system (ARAS) for answering questions about personality. The ARAS is part of the brain structure and has been proposed to deal with cortical arousal, hence the term arousal theory. Eysenck compared levels of arousal to a scale of introversion versus extraversion. The comparison of these two scales was then used to describe individual personalities and their corresponding behavioral patterns.[6] Gray disagreed with Eysenck's theory because Gray believed that things such as personality traits could not be explained by just classical conditioning.[7] Instead, Gray developed his theory which is based more heavily on physiological responses than Eysenck's theory.