3.2 Measuring stress

1. 3.2 Measuring stress

2. Learning outcomes Understand these three studies related to measuring stress: • Physiological measures (Geer, J. and Maisel, E. (1972) ‘Evaluating the effects of the prediction-control confound’, Journal of Personality and Social Psychology 23 (3), 314–19); • Self-report (Holmes, T. H. and Rahe, R. H. (1967) ‘The social readjustment rating scale’, Journal of Psychosomatic Research 11, 13–18); • Combined approach (Johansson et al. (1978) ‘Social psychological and neuroendocrine stress reactions in highly mechanised work’, Ergonomics 21 (8), 583–99).

3. Physiological measures Key study: Geer and Maisel (1972) Aim • To see if perceived control or actual control can reduce stress reactions to aversive stimuli (photos of crash victims). Method • Laboratory experiment.

4. Participants • 60 psychology undergraduates from New York University. Design • Independent design as participants were randomly assigned to one of three conditions.

5. Procedure • Each participant was seated in a sound-shielded room and wired up to galvanic skin response (GSR) and heart-rate monitors. • Group 1 were given actual control over how long they saw each photograph for. • Group 2 were yoked to the actual control group, warned how long the photos would be shown for and that a noise would precede them. • Group 3 were also yoked to actual control group, but were told that that from time to time they would see photographs and hear tones.

6. Procedure (cont.) • A Beckman Model RB polygraph was used to collect psycho-physiological data. • The data was converted from a voltmeter to a printout. • Each recording was performed in a sound and electrically-shielded room to ensure no audio or visual input from the projector would interfere with the data collection.

7. Procedure (cont. 2) • The heart monitors were attached in standard positions, and the GSR electrodes were placed between the palm and forearm of the participants’ non-preferred arm e.g. left arm for right-handed people.

8. Findings • The predictability group (Group 2) were most stressed by the tone as they knew what was coming, but did not have control over the photograph. • The control group (Group 1) were less stressed by the photograph than the predictability group and no-control group (Groups 1 and 2) as they had control.

9. Conclusions • It is likely that having the control to terminate aversive stimuli reduces the stressful impact of those stimuli.

10. Self reportKey study: Holmes and Rahe (1967) Aim • Creating a method that estimates the extent to which life events are stressors.

11. Method • A questionnaire designed to ascertain how much each life event was considered a stressor. Participants • 394 subjects.

12. Procedure • Each participant was asked to rate a series of 43 life events. • Marriage was given an arbitrary rating of 500 and each event was to be judged as requiring more or less readjustment. • It could be based on personal experience and perceptions of other people. • The final Social Readjustment Rating Scale was completed based on the mean scores.

13. Findings • Correlations between groups were tested and found to be high in all but one group. • Males and females agreed. • Participants of different ages, religions, educational level agreed. • There was less correlation between white and black participants.

14. Conclusions • The degree of similarity between different groups is impressive and shows agreement in general about what constitutes life events and how much they cause stress (or readjustment).

15. Combined approach Key study: Johansson et al. (1978) Aim • To measure the psychological and physiological stress response in two categories of employees. Method • A quasi-experiment where workers were defined as being at high risk (of stress) or in a control group.

16. Participants • 24 workers at a Swedish sawmill. • The high-risk group was 14 workers who had to work at a set pace. Their job was complex and they were responsible for their own and their team’s wages. • The control group was 10 workers who were cleaners, or maintenance men.

17. Design • An independent design with participants already working in one of the two categories, so no manipulation of the independent variable.

18. Procedure • Each participant was asked to give a daily urine sample when they arrived at work and at four other times during the day. They also gave self-reports of mood and alertness plus caffeine and nicotine consumption. • The baseline measurements were taken at the same time on a day when the workers were at home.

19. Procedure (cont.) • Each participant gave a urine sample four times during the day, so that their adrenaline levels could be measured. Their body temperature was also measured at the same time. These physiological measurements gave an indication of how alert the participants were. • Self-rating scales of words such as ‘sleepiness’, ‘wellbeing’, ‘irritation’ and ‘efficiency’ were made on scales from none to maximal (the highest level the person had ever experienced). • Caffeine and nicotine consumption were noted.

20. Findings • The high-risk group had adrenaline levels twice as high as their baseline and these continued to increase throughout the day. The control group had a peak level of 1 ½ times baseline level in the morning and this then declined during the rest of their shift. • In the self-report, the high-risk group felt more rushed and irritated than the control group. They also rated their wellbeing lower than the control group.

21. Conclusions • The repetitive, machine-paced work, which was demanding in attention to detail and was highly mechanised, contributed to the higher stress levels in the high-risk group.