A2 Mock - Evaluation of the Biological explanations Flashcards
Evidence of the biological explanations
Biological explanations of stress predict that exposure to frequent episodes of stress will cause various health problems due to elevated blood pressure and its effect on CHD, and increased cortisol reducing immune system functioning. Many studies provide support for these predictions. For example Friedmann and Rosenman found that a Type A personality who have a more reactive fight and flight reaction were twice as likely to suffer from CHD than Type B who do not react as much..
Evidence for Chronic response
Similarly Keicolt-Glaser et al found that the natural killer cell activity (an immune system cell) was lower in medical students during the exam period than a month before. If the immune system is low, we will be more open to diseases and illness, supporting the immune suppression hypothesis. These studies and others support the link between stress, CHD and other health problems. The implications are that we need to be aware of those who are vulnerable to stress related health problems because of stressful experiences, and maybe put interventions in place to help the person to cope and deal with stress better.
Cause and effect?
However, many of the studies supporting the relationship between stress and illness are natural experiments or correlational research and therefore we cannot assume that stress has caused the heart problems. It could be that when stressed our lifestyle becomes less healthy (drink and smoke more, eat poorer diet, exercise less), and these lifestyle changes could have caused the CHD and lower immune system activity not the stress response itself. This is supported by a study by Liu et al (2015) who found that poor health in women caused unhappiness (including stress) rather than unhappiness and stress causing poor health.
Low or high cortisol?
Similarly the role of Cortisol in causing stress-related illness may be more complicated than it appears. For example Heim (2000) found that low cortisol levels have also been linked to poor health. Therefore it seems that a sudden drop in cortisol can be an issue for health as well as high cortisol levels. This suggests that the relationship between cortisol and health/memory problems is not straight forward.
Gender difference?
One issue with a lot of the research into the acute stress response is that it tends to focus on males (e,g, Friedman and Rosenham study) and women may respond differently. This makes the research gender biased. Some evolutionary psychologists suggest that rather than fight and flight (acute stress response) in a stress situation, women may respond to stress in a ‘tend and befriend’ way, nurturing and building up social networks. This behaviour causes the hormone Oxytocin to be released which reduces fear response. Therefore women’s responses and hormones may mean they are protected from the long term effects of stress, and we cannot generalise findings from research on men to women.
