WJEC AS Psychology PY2 - Rahe et al (1970)

Definitions:

• stress: can be defined as the non-specific response of the body to any demand usually when perceived demands exceed perceived abilities to cope

Importance: Selye (1936) showed the importance of stress research in the body by demonstrating that there is a relationship between stress and ilness, creating the field of psychosomatic research

Previous Research:

• Holmes and Hawkins noticed that patients in their care being treated for TB were from poor backgrounds and that it wasn't the poor background itself that increased risk of TB but stress of poverty; Hawkins et al (1957) compared TB patients with non-TB workers in hospital (matched for age, sex, race and income) and found more disturbing life events in the previous 2 years in the TB than non-TB patients
• Holmes and Rahe (1964) suggested that stress could be measured by amount of life events a person experiences; life changes taken from case histories of 5000 patient records given a score by 400 people

Previous Research continued:

• this produced 43 critical life events, the score was given in terms of how much readjustment would be required by average person; average score for each event was known as 'life change unit' (LCU); this in turn produced 43 life events and LCUs for the 'Schedule of Recent Experiences' (SRE) and 'Social Readjustment Rating Scale' (SRRS) = these gave a quantifiable way of measuring stress, enabling relationship between stress caused by change and existing life changes and illness; however ethical constraints meant unfair to expose someone to stressors to see if illness developed; most research using SRRS and SRE were retrospective studies, assessed SRRS scores of ill people to SRRS scores of non-ill people; however retrospective studies do require recalling information, can be subject to memory distortions

Aims:

1) Rahe et al wanted to limit the methodological flaws in retrospective research; aimed to do a prospective study, correlating LCU measured over 2 years with the rate of illness during the 6 - 8 months following the completion of the SRE

• study involved 2664 men who were naval and marine personnel serving aboard 3 US Navy cruisers, of initial sample, 10% lost due to transfer off the ships
• mean age of pps = 22.3 years
• pps required to fill in a military version of the SRE which was a qs documenting significant life changes relating to personal, family, community, social, religious, economic, occupational, residential and health experiences
• each pps completing the SRE every 6 months over a period of 2 years prior to a 6 - 8 month tour of duty at sea
• SRE: each life change on SRE was assigned an LCU, this value reflects severity and readjustment needed for particular event, formulated by sample of US civilians; repeated with no. different samples, increases reliability
• health records: research physician reviewed all sailor's health records, even most minor health changes, enhancing reliability
• neither pps nor medical department were aware of research aims, didn't realise SRE qs results would be used to make a link with health records

Results from the Experiment:

• no significant correlation between 2 year period prior to cruise and cruise period illness
• significant positive correlation between 6 month period prior to cruise and cruise period illness at +.118
• relationship was strongest for cruisers 1 and 3
• although correlation is small, it did indicate a positive relationship between LCU and health
• crew members divided into 10 groups according to total LCU; group 1 contained lowest TLCU scores and group 10 the highest; LCU groups divided into 4 bands:
  - LCU group 1,2 - mean illness rate 1.405
  - LCU group 3,4,5 - mean illness rate 1.541
  - LCU group 6,7,8 - mean illness rate 1.676
  - LCU group 9,10 - mean illness rate 2.066
• shows clear correlation between higher the TLCU score, higher the mean illness
• TLCU differences most apparent in cruiser 1 and 3 in the married, enlisted men compared to young, single sailors

Conclusions from the Experiment:

• results from this prospective study support notion of linear relationship between TLCU and illness rate; important to note that illnesses were generally minor in degree and life changes few and low significance which in effect adds to strength of results found
• results for cruiser 2 not as strong, it had the most arduous deployment which suggests that in stressful situations the effect of previous life changes is overwhelmed by current environmental stresses

STRENGTHS

• SRE was an especially adapted scale appropriate for military personnel, including items such as being selected for promotion = increases reliability
• double blind collection of medical data = no demand characteristics or researcher bias
• qs = quick and effective, collect lots of data compared to eg interviews

WEAKNESSES

• androcentric and ethnocentric, hard to generalise findings to females/different cultures/countries = low pop. validity
• generally young age group, difficult to generalise = low pop. validity
• problem of cause-effect: just because 2 variables correlate doesn't mean 1 causes the other, cannot conclude that life event cause anxiety/stress and therefore illness, possible that existing natural level of anxiety/stress influences impact of life events and therefore illness
• SRE doesn't distinguish positive/negative interpretation of events, if viewed positively would illness occur? also individual differences like finance/social support could vary
• ethics: deception, unaware of study, therefore no informed consent or right to withdraw, lack of confidentiality due to health records access

1. Cohen et al (1993) SUPPORTS

• measured pps stress levels, lack of control and LCU using SRRS
• pps split into 2 groups: control group given non-infectious nasal drops and experimental group given drops containing common cold, both groups quarantined for 7 days
• found that pps with high LCU scores more likely to be infected

SUPPORTS as shows that there does seem to be a positive relationship between stress and LCU to illness, and that the higher the LCU score, more likely a person is to be ill

2. Kiecolt-Glaser (1991, 1984, 1987) SUPPORTS/DEVELOPS

• showed immune function is significantly reduced in highly stressed, groups such as carers for Alzheimer's patients, women divorcing and students sitting exams
• killer t-cell activity reduced and speed of puncture wound healing

SUPPORTS/DEVELOPS as suggests some illnesses might be indirectly linked to life changes, suggests that life changes affect immune functioning which makes humans more likely to be ill but only if stressed person exposed to harmful pathogens (bacteria, virus) too

3. Delongis et al (1988) CONTRADICTS

• used hassles and uplifts scale to assess minor sources of stress in 75 married couples (eg weight concerns, worry over health of family member)
• uplifts included as thought to reduce impact of daily hassles (eg completing a task, feeling healthy)
• found correlation of +.59 between hassles score and next day health problems (eg flu, sore throat) but no correlation between health and couples score on LCU scale or for uplifts

CONTRADICTS Rahe et al's findings as suggests that possibly, for most people, minor incidents have more daily impact than major incidents in the SRE/SRRS; if a life change is viewed positively (uplift) it is unlikely to be linked to illness whereas only negative changes (hassles) will be; major life events on the SRE are not frequent enough to apply to majority of people so lacks validity as measure of stress; HOWEVER, study still acknowledges that stress is linked to illness but disputes cause of stress