1. Psychology Stress Studies

2. Kiecolt-Glaser et al. (1984) – Exam-related stress and the immune system Method: natural experiment with 75 students where a measure of how well the participants’ immune system was functioning (achieved by taking blood samples from the medical student and measuring activity of natural killer cells) was taken a month before, and then during, the exam period. The stress was also measures using the Social Readjustment Rating Scale (SRRS), used to divide the student into a ‘high stress’ and ‘low stress’ group. They also completed a loneliness scale so they could be divided into a ‘high loneliness’ and ‘low loneliness’ group. Findings: found that NK cell activity was significantly reduced in the second blood sample (immunosuppression). The high stress group had lower NK cell activity than the low stress group, as did the high loneliness group. This may be due to the lack of social support. Limitations because it is a natural experiment, we can only conclude that there is a relationship between stress and the immune system, but cannot claim that stress caused the changes another limitation is that the sample for this experiment was volunteers and may not behave the same way as other people, but it was concluded that the sample was representative in addition to this, the experiment only considered a small part of the immune system so it is possible that other aspects of the immune system were not effected

3. Kiecolt-Glaser et al. (1995) – Stress and wound healing Method: natural experiment of 26 women separated into a high stress group (who cared for an elderly relative) and low stress (control) group, where the effect of stress was measured in two ways: participants were give a ‘wound’ using a punch biopsy and the time taken for the 3.5mm hole to heal was measured; and the cytokine, a component of the immune system, levels were measured. The participants stress levels were assessed using a ‘perceives stress scale’. Findings: in the stress group, wound healing took around 9 days longer and they had much lower cytokine levels. The carers also had a higher perceived stress score. Strengths: has real-world applications: in hospitals patients may be stressed due to loneliness which could hinder their recovery lots of supporting research Limitations: only a very small sample was used so it would have to be repeated with a bigger sample in order to be representative

4. Evans et al. (1994) – Shorter-term stress and the immune system Method: measured a component of the immune system in saliva (slgA) in 18 students, repeatedly before the stress event to establish a baseline and then once after the stress event (a public verbal presentation which would contribute to their final degree classification). The levels of cortisol in saliva were also assessed to confirm stress. Findings: immune system activity increased with greater stress; the levels of slgA were higher after the presentation. This suggests that a short-lived stressor may have an ‘upregulation’ effect on the immune system. Levels of cortisol also increased in the before and after samples (higher stress). Strengths: results of this study are supported by other research: for example, Zeier et al. (1996) assessed levels of slgA in air-traffic controllers before and after work sessions. Found an increase in both slgA and cortisol at the end of their work session Limitations: may be extraneous variables: it is possible that stress of delivering a speech reduced the amount of saliva in the mouth so the concentration of slgA was higher researchers found that reduced saliva cannot explain the results

5. Holmes and Rahe (1970) – The SRRS Method: analysed 5000 patient records and produced a list of 43 fairly major life events, which were then rated for the amount of readjustment required – is relation to marriage as a baseline with 500. The scores were averaged to create the life change units (LCU) for each event. Findings: the list of life event included both positive as well as negative life events, which shows that any life change has psychological cost and is deemed stressful. The scores for all events experience in the past year are added up and those with a score >300 were at greater risk of becoming ill. Limitations: overlooks smaller, everyday events such as every day hassles people may not have experience any life events but may still be stressed Strengths: SRRS has widespread application and has been valuable in many studies and has been used as a basis for developing a number of similar scales

6. Rahe (1970) – Life changes in navy personnel Method: study of 2664 men serving on three US Navy cruisers, with an average age f 22.4 years. Stress was assessed using the SRE (similar to SRRS but more relevant to military personnel) for previous 2 years. Illness assessed using sickroom record over a period of 6 months, excluding and that seemed to be motivated by the desire to get out of work. Findings: small but significant correlation of +1.18 between LCU score and illness. Data was also analysed by dividing the sailors into 10 groups according to their LCU scores. The low LCU group had an illness rate of 1.4; the high LCU group had a mean illness rate of 2.1. Limitations: both the LCU scores and the level of illness were relatively low, which made it more surprising that a positive correlation was found retrospective recall of life event may be unreliable and life events may have occurred that where then not recalled this may affect the validity of the results

7. Cohen et al. (1993) – Life changes and the common cold Method: recruited 394 healthy participants (aged 18-54) to consider the relationship between stress levels and the likelihood of becoming ill. Stress levels were assessed using an adaptation of the SRRS – 41 items related to themselves and 26 to close others. They were all asked to indicate whether the events had a positive or negative impact on their life. All participants were exposed to the common cold virus and assessed in quarantine for the developing illness – nose secretions, immune activity, body temperature, weighing mucus produced. Findings: those with LCU were much less likely to develop a cold (44% compares to 32%). The number of negative events was positively correlated with severity of symptoms. The severity of symptoms was somewhat related to life stressors (affecting temperature but not mucus). Strengths: study was well controlled: personality and health related behaviours were taken into account this enhances the validity of the findings Limitations: may be extraneous variables: it is possible that stress of delivering a speech reduced the amount of saliva in the mouth so the concentration of slgA was higher researchers found that reduced saliva cannot explain the results

8. DeLongis et al. (1982) – Daily hassles scale Method: they believed that daily hassles may have a greater potential for causing increased stress than life events. Uplifts also need to be taken into account as they have potential to increase stress. Investigated 100 adults aged 45-64 and completed a daily hassles (once a month), daily uplifts (once a month), life events (2.5 years preceding) and a health status questionnaire over a 9-month period Findings: there was a negative correlations between daily hassles and health status, and a much weaker negative correlation between uplifts and health status. There was found to be almost no correlation between life events and health status. Limitations: The sample was of older people; younger people may not be as affected by daily hassles Correlational data – cause and effect cannot be established Does not tell how/why hassles and uplifts have this effect

9. Twisk et al. (1999) – Hassles and CHD Method: a longitudinal study with 166 young adults tested at 27 and then 29. ‘Everyday Problem Checklist’ was used to assess daily hassles experience over the previous 2 months. The ‘Life Events List’ was used to assess 89 possible life events and participants selected those experienced over the previous year. Risk of CHD was assessed through biological and lifestyle factors. Findings: a positive correlation was found between: daily hassles and lipoprotein levels (not blood pressure or body fat); increase in daily hassles and smoking; and daily hassles and physical activity. Strengths: Longitudinal study: the changes in daily hassles could be considered. The score used was only related to whether a person had got increasingly stressed (how daily hassles may affect health). Limitations: Correlations in both negative and positive behaviours could be due to the fact that people handle stress in different ways, with some people doing both This means that no single generalisation can be made

10. Kuper and Marmot (1997) – Workplace stress in civil servants Method: a longitudinal study of workplace stress on 10,000 civil servants working in London. They gained self-report measures of job control, workload and social support. 11 years later CHD risk was assessed (either the participant had died as a result of CHD, or the participant had significant chest pain or a non-fatal heart attack). Findings (workload): participants in the higher grades did report higher workload, and more job control (combination of high workload/low job control is called to job strain model). Participants who reported high workload were at greater risk for CHD than those reporting low workload. Findings (job control): low job control (lowest grade of employment) and high workload were at the greater risk for CHD (more significant in younger workers and unaffected by social support) than low job control/low workload. Lack of job control was less important than higher workload. Limitations: Sample of white collar workers from an urban population but did include a range of socio- economic groups (must be generalised cautiously) Other factors (low pay, job insecurity, working conditions) would contribute to the workplace stress. Individual differences can also have effects.

11. Johansson et al. (1978) – workplace stress in a Swedish sawmill Method: conducted a natural experiment of 14 ‘high risk’ individuals (sawyers, edgers and graders) comparing them to a control group (stickers, repair men and maintenance workers). Measured: levels of adrenaline on work and rest days; self-report of job content; and stress- related illness. Findings (workload): high-risk group reported heavier responsibility and also had more ill- health. Controls group worked in smaller teams, felt lower demands for precision and less demands for continuous attention. Findings (job control): the high-risk group reported that their jobs were repetitive and constrained and since the tasks were pre planned there was less possibility of individual design of work routines and self-control of work pace (low job control). The high-risk group had higher adrenaline levels especially on work days. Limitations: Self-report is not necessarily accurate (answers may be influenced by social desirability bias), challenging the validity of the findings. Work underload was overlooked and may be just as much of a problem.

12. Friedman and Rosenman (1974) –Type A and B behaviour Method: sent out questionnaire to 200 executives and doctors asking for their opinion and found that most people believed persistent stress was due to a cluster of personality characteristics: intense ambition, competitiveness, preoccupation with deadlines and a sense of time urgency. This was describes as type A behaviour. Type B behaviour was more relaxed and easy-going. A sample was selected of 3,154 men aged 39-59 from San Francisco, California. Individuals were classes as Type A or Type B using a structured interview (both the answers to questions and observations of behaviour in interviews). Deaths due to CHD were recorded over a period of 8 ½ years. Findings: half were classes as Type A, with other risk factors recorded like smoking habits, exercise, blood pressure etc. At the end of the study, the death rate per 1000 person-years was 2.92 for Type A and 1.32 for Type B (type A with higher blood pressure, cholesterol and lipoproteins). Strengths: Has real world applications Limitations: Follow-up research found less effect of Type A behaviour on CHD

13. Kobasa (1979) – Hardy Executives Method: a ‘hardy personality’ is a personality characteristic, which provides a defence against the negative effects of stress. Two questionnaires were sent out to 837 executives in a large company in America, assessing both life events over the previous 3 years (SRRS) and illness. Two sample were then selected. 86 hardy individuals (high stress, low illness) and 75 non- hardy individuals (high stress, high illness). Locus of control, commitment and challenge was measured using self-report questionnaires. Findings: a strong, positive correlation between SRRS score and illness and the scores for control, commitment and challenge were higher in the hardy group. This suggests that a hardy personality enables an individual to cope with more stressful life events. Limitations: All-male sample: later research found less of an effect with women Finding are correlational: the study assumes that hardiness enabled the group of executives to cope with high stress and that’s why they experiences less illness but it could be that those who experience high illness found this reduced their hardiness. This suggests that a cause and effect relationship cannot be established