Outline and evaluate psychological research into stress and the immune system (12 marks)
Stress causes the release of ACTH from the pituitary gland which signals the adrenal glands to release anti-inflammatory hormones. This weakens the immune system leaving the body vulnerable to infection and illness. Raised levels of cortisol suppresses the TH1 immune response.
Kiecolt-Glaser et al conducted a natural experiment into acute stress, the aim was to see if the stress of exams had an effect on the immune system. Blood samples were taken from medical students before and during the exam period, T-Cell activity was measured in the blood samples. The findings showed that T-Cell activity was significantly higher before exams which suggests that acute stress caused reduced immune system functioning. Showing that stress is linked to a weakening of the body’s immune system.
A weakness of this study is that it lacks population validity, as it was carried out on medical students. This means that the findings may not be replicated in of individuals and caution should be taken when generalising the findings to the whole population because medical students might not be representative of everyone.
Cohen carried out a study into chronic stress, looking at whether conflict in interpersonal relationships reduced immune system functioning. It was found that couples whose interactions are negative and hostile for longer than a month were at risk of developing illness when exposed to an infection as they had less adaptive immunological responses after these infections. They concluded that chronic stress caused a suppression of the immune systems functioning.
A weakness of this study is it has methodological issues, for example the results were measured using self-report methods from the participants. This means that the answers may not be valid due to social desirability bias. This