PSYA2 - Type A behaviour and disease - Friedman and Rosenman
Conclusion:
The stress response inhibits digestion, which leads to a higher level of cholesterol in the blood, and this places Type A's at risk of CHD.
Aim:
Aimed to test the hypothesis that the type A individuals were more likely to develop coronary heart disease than Type B's
Criticism #2
It has proved fairly difficult to repeat the findings of Friedman and Rosenman (1959, 1974). Indeed, there are several later studies in which the correlation between personality type and CHD was non-signigicant. These later findings cast doubt on the notion that CHD depends in part on the Type A personality.
Participants:
Self selected sample of 3200 Californian men aged between 39 and 59 years old.
Friedman and Rosenman: What years?
1959, 1974
Findings:
257 participants developed CHD during the 8 & 1/2 years, 70% of whom had been classified as Type A. This was nearly twice as many as were Type B, even when other factors known to be associated with heart disease were taken in to account. Type A's were found to have higher levels of cholesterol, adrenaline and noradrenaline than Type B's. A significant correlation was found between personality type and CHD
Procedure:
This was a longitudinal study where all the participants were healthy when it started in 1960 and were assessed over a period of 8 and 1/2 years. The first part of the study included a structured interview and observation, which assessed personality type and current health status. The participants were then given a classification type. Part two was followed up 8 years later when incidence of CHD was recorded. A correlational analysis was carried out to test the association between type A/B behaviour pattern and CHD.
Criticism #1
Type A behaviour pattern consists of a number of characteristics and so the variable type A lacks precision. It is too broad to be useful, because it is not clear which aspect of Type A is most strongly associated with CHD. Consequentially, the research lacked validity as it did not precisely measure what it set out to.