Physiological
One way to assess arousal is to use
electrical/mechanical equipment to take measurements of blood pressure, heart
rate, respiration rate, or galvanic skin response (G. S. R.). The Polygraph
measures all of these simultaneously. Miniature Polygraphs can be carried
around. Researchers using a miniature Polygraph were able to find that ambulance
workers had higher blood pressure whilst at work compared with when they were
at home (Goldstein et al. 1992).
However, being wired to a polygraph could increase stress.
Blood or urine samples can be assessed for
the level of hormones that the adrenal glands secrete. There are two main
classes of hormones: corticosteroids (for example cortisol) and catecholamines
(for example, adrenaline and noradrenaline. Measurements need to be analysed by
a chemist using special procedures and equipment. However, having blood taken
could cause stress.
There are several advantages to using
measures of physiological arousal to assess stress. Physiological measures are
reasonably direct and objective, quite reliable, and easily quantified. The
disadvantages are that the techniques are expensive, the technique is stressful
for some people and the measures are affected by factors such as gender,
weight, activity prior to measurement and such substances as caffeine. Psychological stress does not always produce
physiological arousal.
Psychological
The most widely used scale of life events has
been the 'social readjustment rating scale (SRRS.)' developed by Holmes and
Rahe (1967). The scale was made by constructing a list of events that were
derived from clinical experience. Hundreds of men and women of various ages and
backgrounds rated the amount of readjustment needed by people experiencing each
of the stressful events. They were asked to give the average degree of
readjustment.
To measure the amount of stress people have
experienced subjects check off each life event they have experienced during the
past 24 months. The values of the check items are then totalled to give the
stress score.
A survey of nearly two thousand eight hundred
adults who filled in a version of the SRRS found that 15% experienced none of
the events during the prior year, and 18% reported five or more. The three most
frequent events were "took a vacation" (43%), "the death of a
loved one or other important person" (22%), and "illness or
injury" (21%). The older the person the fewer life events reported and the
more educated the person more life events were reported. Single, separated, and
divorced people reported a larger number of events compared with married and
widowed individuals (Goldberg & Comstock, 1980).
Strengths and weaknesses of the SRRS.
Problems with the scale
High correlation between men and women, Catholics and Protestants. Not so high for Black Vs White.
The SRRS has face validity because many of
the events listed are easily recognisable as stressful events. The values
Allocated to each stress event have been carefully calculated from data
provided by the opinions of many people. The survey form can be filled out
easily and quickly.
Other life events scales
The life experiences survey (LES)
This is an improvement. It consists of 57
items that are stated relatively precisely, for example, "major change in
financial status (a lot better off or a lot worse off)." It uses a
seven-point scale, ranging from extremely negative (-3) to extremely positive
(plus three) (Sarason et al, 1978).
The PERI life events scale
Again this is an improvement. It contains 102
items describing a gain, a loss, or an ambiguous outcome. The items are stated
clearly and organised into 11 topic areas, including work, finances, family,
and health (Dohrenwend et al, 1978).
The unpleasant events schedule (UES)
Again this is an improvement, although it
will take a lot longer (usually one hour) to complete. It consists of three
hundred and 20 items (although a shorter, 53-item form is also available).
There are a number of categories, such as sexual/marital/friendship and
achievement/academic/job. The items are stated relatively precisely and are
rated on a three point scale twice, first for frequency and then for
adversiveness. The two ratings are multiplied, and a total score is summed (Lewinsohn
et al, 1985).
The above is designed to measure stress in
adults. The most widely used scale for children is the life events record which
is similar to the SRRS (Coddington, 1972). The items are relevant to children,
covering topics such as "divorce of parents" and "change to a
different school". The values assigned to the items are dependent upon the
child's age. Parents are able to fill in the Questionnaire for younger
children.
Daily hassles
Kanner et al (1981) - minor stressors and pleasures of everyday life might have a more significant effect on health than the big events. - Takes account of the cumulative nature of stress.
Richard Lazarus and his associates designed
this scale. It concentrates on recent stressors, the annoying things that
happened to everybody everyday. The hassles are rated as having been
"somewhat," "moderately," or "extremely" severe.
100 middle-aged adults were tested monthly
over a nine-month period. The 10 most frequent hassles reported were:
In addition to the hassles scale there is
another instrument, the uplifts scale, which measures the good events in life.
It is reasonable to assume that experiencing events that bring peace,
satisfaction, or joy would allow people to endure the hassles of daily life.
Uplifts experienced in the past month are recorded on a three-point scale. The
uplifts are rated as having been "somewhat," "moderately,"
or "extremely" strong. The 10 most frequent uplifts reported were:
One study tested middle-aged adults, using 4
instruments:
There is a weak correlation between hassles
scores and health status, as well as between life event scores and health status.
Hassles were more strongly associated with health than life events. There was
no association found between uplifts scores and health status for men, but
there was for women.
Self-report measures of life events are
unreliable. A study had subjects fill out a scale regarding life events they
experienced during the prior year. The subjects then filled out the same
Questionnaire every month for a year. Towards the end of the year the reports
were quite different from the ones made at the beginning of the year (Raphael,
et al. 1991).
Above methods only provide a snapshot.
Stress varies from day to day.
Gulian et al (1990) - study of British drivers. Completed psychometric tests (e.g. Rotter's Internal - External Locus of Control Scale).
Also filled in a diary of their feelings while driving over 5 days.
More stress in the evening and midweek.
Stress varied with age and experience, health condition, sleep quality, driving conditions, driver's perception of driving as stressful.
Douglas et al (1988) used diary and physiological measures
100 fire fighters from 12 stations.
Heart rate recorded for minimum of 48 hours (used portable electrocardiogram)
Results yielded a 'Ventricular cardiac strain score'.
High scores were found to correspond with number of call-outs, level of seniority, and stressful events recorded in diaries.
Notes
from Canberra University
Stress
Theories
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