The Relationship between Stress and the Immune System

Question 1

Which gland to corticosteroids shrink?

Answer 1

The thymus gland.

Question 2

The shrinkage of the thymus gland prevents the production of what?

Answer 2

T-cells.

Question 3

What is the function of the cells produced by the thymus gland?

Answer 3

T-cells seek and destroy cells that are infected with bacteria and viruses.

Question 4

Why does the immune system not function as effectively during stress?

Answer 4

Because so many other systems are needed for the fight or flight response, systems that are not immediately required, such as the immune system, are suppressed to conserve energy.

Question 5

What was the aim of Kiecolt-Glaser’s study?

Answer 5

To find out if people who were more stressed would take longer to recover from a wound that people who were not so stressed, showing if the functioning of the immune system is affected by stress or not.

Question 6

What were the two groups of participants in Kiecolt-Glaser’s study?

Answer 6

Condition 1: Females who had been carers of relatives with Alzheimer’s for an average of 8 years.

Condition 2: A matched control group for age and income who had not been carers of Alzheimer’s sufferers.

Question 7

What was the wound that the researchers in the Kiecolt-Glaser study made called?

Answer 7

A punch biopsy.

Question 8

What substance did the researchers in the Kiecolt-Glaser study measure for?

Answer 8

Interleukin-1B.

Question 9

What was the key finding in the Kiecolt-Glaser study?

Answer 9

Those in the more stressful situations took longer to recover than those in less stressful situations.

Question 10

What were the average healing times in the Kiecolt-Glaser study?

Answer 10

Condition 1 (Carers): 48.7 days.

Condition 2 (Non-carers): 39.3 days.

Question 11

What two things, other than the average healing times being longer, did the researchers notice about the participants in condition 1 in the Kiecolt-Glaser study?

Answer 11

The stressed group had a larger wound size
and
the stressed group produced less interleukin-1B.

Question 12

What do the results of the Kiecolt-Glaser study show?

Answer 12

High levels of psychological stress can damage the immune system and slow recovery.

Question 13

What are the practical applications of the Kiecolt-Glaser study?

Answer 13

The study has practical applications for people recovering from illness and surgery, and may lead to immune system boosting drugs for those that are stressed.

Question 14

How many participants were in each condition in the Kiecolt-Glaser study?

Answer 14

13 participants were in each condition.

Question 15

Are the findings in the Kiecolt-Glaser study generalisable? Why/why not?

Answer 15

No. Only women were used.

Question 16

Why can you not establish cause and effect in the Kiecolt-Glaser study?

Answer 16

The study used a naturally occurring independent variable, so there is a lack of control over extraneous variables. For example, those caring for Alzheimer’s sufferers were more likely to be on medication than the control group- this may have affected their immune system.

Question 17

How many people did Cohen et al study?

Answer 17

394.

Question 18

How did Cohen et al assess their participants’ stress?

Answer 18

On a scale from 3 (lowest amount of stress) to 12 (highest amount of stress, using the life event stress scale and participants’ own perception of their stress and depression levels.

Question 19

What were participants in Cohen et al’s study injected with?

Answer 19

A cold virus.

Question 20

What were the results of Cohen et al’s study?

Answer 20

47% of participants with stress ratings of 11-12 caught a cold,
whereas only 27% of those with a stress rating of 3-4 caught a cold.

Question 21

What extraneous variables did Cohen et al’s study control?

Answer 21

Gender
Education
Diet
Previous exposure to the cold virus

Question 22

What did Cohen et al’s study show?

Answer 22

There is a link between stress and a lowered immune system.

Question 23

Were Cohen et al’s results representative? Why/why not?

Answer 23

Yes. A relatively large sample size was used.

Question 24

What are the weaknesses of Cohen et al’s study?

Answer 24

• The research only shows that there is a relationship between stress and illness, as you cannot control all variables such as how effective an individual’s immune system is or how well they cope with stress. Only 20% more people in the high stress group caught a cold than people in the low stress group. This suggests that stress levels are not the only factor involved.
• The stress levels were only determined through questionnaires. People may exaggerate or underestimate their level of stress. They may also be affected by a social desirability bias, wherein they give answers that they believe are more socially acceptable.