<P> The two cardiologists who developed this theory came to believe that Type A personalities had a greater chance of developing coronary heart disease . Following the results of further studies and considerable controversy about the role of the tobacco industry funding of early research in this area, some reject, either partially or completely, the link between Type A personality and coronary disease . Nevertheless, this research had a significant effect on the development of the health psychology field, in which psychologists look at how an individual's mental state affects physical health . </P> <P> 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 . 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 . 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?" 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 . </P> <P> The hypothesis describes Type A individuals as outgoing, ambitious, rigidly organized, highly status - conscious, sensitive, impatient, anxious, proactive, and concerned with time management . People with Type A personalities are often high - achieving "workaholics". They push themselves with deadlines, and hate both delays and ambivalence . People with Type A personalities experience more job - related stress and less job satisfaction . </P> <P> In his 1996 book dealing with extreme Type A behavior, Type A Behavior: Its Diagnosis and Treatment, Friedman suggests that dangerous Type A behavior is expressed through three major symptoms: (1) free - floating hostility, which can be triggered by even minor incidents; (2) time urgency and impatience, which causes irritation and exasperation usually described as being "short - fused"; and (3) a competitive drive, which causes stress and an achievement - driven mentality . The first of these symptoms is believed to be covert and therefore less observable, while the other two are more overt . </P>

Which type of personality is more prone to stress