To find out the stress levels Johansson recorded levels of stress hormones on work days and rest days, he found that the high risk group of finishers secreted more stress related hormones on work days than on rest days and higher levels than that of those in the control group of cleaners, the finishers also showed more signs of stress related symptoms e.g. Headaches and a higher case of absenteeism than that of the cleaners.
(c) Discuss research into the relationship between stress and cardiovascular disorders.
(18 marks)
There have been many studies undertaking research into the correlation between cardiovascular disorders and stress.
Friedman and Rosenman undertook a study into coronary heart disease (CHD) in 1959, their hypothesis was that patients who displayed type A behaviour; who fitted into the group that had a pattern of impatience, competitiveness and hostility where more likely to get CHD than those who fitted into the type B group; these displayed a pattern of being laid back and relaxed.
Friedman and Rosenman took a sample of 3000 males from California, USA aged between 39 and 59, who were healthy at the start of the study, they established which personality group the sample fitted into through a series of questions put forward in an interview.
Friedman and Rosenman found that after eight and a half years 257 men in the sample were diagnosed with CHD and that of this group 70% had been previously classed as a type “A” personality. They also found hat type “A”s had a higher level of cholesterol and that twice as many men in the type “A” group had died compared to the type “B” group.
Friedman and Rosenman concluded that Type “A” personality is more likely to be associated with CHD. Because type “A” is also linked to other factors that cause CHD, such as smoking (which we now know can cause CHD), it is not certain if type “A” is a direct or indirect cause of CHD.
Cirtisms of this study include that it is an extremely biased sample, with the sample being all males from California; this means it lacks population validity.
It is also critised due to the fact that it is not know whether CHD is brought on souly from the type of personality you are as Friedman and Rosenman concluded there were a series of extraneous variables that could not be controlled in this study i.e. smoking.
It is classed as over simplistic with the sample being classed as one or the other as there are only two choices.
Positive critisms of this study include that it has a large sample at 3000 males and that it was a longditudinal study running for 8 ½ years.
Other studies that back up friedman and Rosenman into stress and the effect on the cardiovascular system are that of Williams who conducted a study on 13000 people, he got the sample to fill in a questionnaire which consisted of 10 questions and placed them on an anger scale. He found that six years later of the 13000 sampled he found 256 had experienced a heart attack and that those who scored most highly on the anger scale were nearly three times more likely to experience one. This study has good time validity as it was carried out in 2000.
