Stress and the immune system
It is suggested that stress can result in immunosuppression which can lead to stress-related illnesses such as Coronary Heart Disease and high blood pressure.
Kiecolt and Glaser conducted an experiment to see the effects of stress on the immune system. This was achieved by taking blood samples of 75 medical students one month before and during their examination period. They then compared the two blood samples and found decreased leucocyte activity in the sample taken during high levels of ...view middle of the document...
The experiment was a field experiment so there was no manipulating of the independant variable to deliberately cause stress to the participants which makes it ethical. It also means the research has ecological validity and can be applied to the wider world. However, a field experiment may have extraneous variables which impact the results. For example, the student lifestyle of having little sleep and poor accomidation may have been an alternative source of stress. Another disadvantage is that there was a biased sample used of students. It may not be possible to generalise students’ response to stress compared to the general population.
Riley also did a study using rats on a rotating turntable for five hours. He found that over time, their white blood cell activity dramatically decreased and when injected with carcinogens they developed tumours more rapidly than a control group of rats. This showed that stress can make us reduce our immune system’s activity which can cause diseases to worsen or progress more rapidly. However, as the research was conducted on rats it can be argued that it can’t be applied to humans as out stress response may differ.