Outline and evaluate research into personality types and stress related illness. (12 marks)
Friedman and Rosenman identified two types of personality that relate to individual responses to stress these were type A and type B. Type A personalities are said to be impatient, competitive, ambitious, aggressive, find it hard to relax. In contrast, type B personalities are the opposite, being less driven, more easy going, patient and able to relax.
Friedman and Rosenman conducted a longitudinal study in which 3000 middle aged men in california were examined for signs of CHD, while there personalities were also assessed using a structured interview. The findings showed after 81/2 years, twice as many type A participants had died of cardiovascular problems. while over 12% of type A participants had experiencedd a heart attack compared to just 6% of type B participants. Friedman and Rosenman concluded that Type A behaviour signifcantly increased the risk of coronary heart disease, and that personality types can contributre to stress related illness.
A strenght of this study is its sample size as there is a increase in population validity. This is because 3000 participants were used which therefore provides a more representative set of results. However on the other hand a criticism of this study is it also lack external validity as all the participants were male therefore it cant be generalised to other cultures.
Furthermore a study which is against Friedman and Rosenman is Myrtek who carried out a meta-analysis of 35 studies and found an assoication between CHD and a component of type A personality which was hostility, however other than this, there was no evidence of an association between type A personality and CHD.
An advantage of using a meta analysis is it is more reliable as the results can be generalised while as it is a correlation it can show the cause and