BIOLOGICAL - Studies Flashcards
List 2 studies looking at stress and the immune system
Cohen
Kiecolt-Glaser
Cohen: Method
Ppts had their stress index measured using a questionnaire that also took into account their ability to cope and their feelings about their stress. They were then given nasal drops that infected them with cold viruses.
Cohen: Results
When tested by doctors there was a direct correlation between their stress index and the probability that they developed a cold.
Cohen: Conclusion
The higher the individuals stress index the more likely they were to develop the cold
Cohen: Evaluation
Does not prove causality as it does not consider extraneous variables e.g. poor diet may increase chance of illness
Kiecolt-Glaser: Method
Looked at number of NK cells of 75 medical students a month before their exams and then during exams
Also completed a questionnaire to assess their psychiatric state, their level of loneliness and number of life events.
Kiecolt-Glaser: Results
On the day of their finals, they had significantly fewer natural killer cells.
Loneliness, lots of life events and problems such as depression were all associated with a weak immune response.
Kiecolt-Glaser: Conclusion
Stress and life events have a negative impact on the immune system
Kiecolt-Glaser: Evaluation
Lacks population validity
It is a natural experiment since it took advantage of a naturally occurring event; examinations.
The independent variable (IV) was exam stress, a long-term form of stress. Most studies have concentrated on short-term stress.
Could not control variables
Which study showed short term stress can benefit the immune system?
Segerstrom and Miller
What did Segerstrom and Miller find?
using a meta-analysis of other studies and concluded short term stress boosts immunity whereas long term, chronic stress suppresses immunity.
The longer the stress continues the weaker the immune therefore we are more prone to infection
What are 4 methodological issues concerned with using life events to measure stress?
Individual differences
Causality & correlation
Positive life events
Self-report
