You are all probably feeling a little stressed right now with all the revision but I've tried to make this
as simple and easy to understand as poss.
Selye's definition = stressor -> stress response
Transactional definition = stressor + cognitions -> stress response
Parts of the body involved in the Stress Response!
- CNS (central nervous system) made up of the BRAIN and SPINAL CORD. The hypothalamus at the base of
the brain is important!
- ANS (autonomic nervous system) network of nerve pathways (brain to organs, bloodstream
+ glands). MAINTAINS BODILY FUNCTIONS. 2 Subdivisions : Sympathetic Branch [arouses body] and Parasympathetic Branch [Calms
+ relaxes body].
- Endocrine System endorcrine glands secrete hormones into blood stream. The Pituitary
Gland and Adrenal Glands (adrenal cortex and adrenal medulla) used in stress response.
Two pathways (need to know these VERY well for a 6 mark question so memorise them!)
* higher brain tells hypothalamus to begin pathway * hypothalamus connected to pituitary gland by infindibulum
* hypothalamus releases corticotrophic-releasing hormone (CRH) that stimulates pituitary gland to produce adrenocorticotrophic
hormone (ACTH) * travels to adrenal cortex and stimulates release of corticosteroids into bloodstream * corticosteroids
mobilise energy reserves and sustain blood flow and heart rate *
At the same time the 2nd pathway is working...
* when info of stressor is known, the hypothalamus activates the sympathetic branch of the ANS,
which stimulates adrenal medulla to release adrenaline and noradrenaline into bloodstream * the 2 hormones reinforce
the activation of the sympathetic ANS - stimulate heart rate, raise blood pressure, mobilise energy reserves
Stage 1 - ALARM : stressor perceived (internal or external)... activation of two pathways... body prepared
for energy expenditure...
Stage 2 - RESISTANCE : stress response fully activated and coping... outside - back to normal... inside
- body's resources not being replaced quickly enough...
Stage 3 - EXHAUSTION : is stressor is long-lasting hormone reserves could become depleted... as systems
become exhausted, stress-related conditions would appear (eg high blood pressure)...
Evaluation of GAS
+ first systematic attempt to describe stress response.
- difficult to generalise animals to humans as humans are physically different. humans also tend to respond
mostly to psychological stressors.
- it ignores individual differences (eg gender). research shows the view that we all respond the same is limited.
STRESS AND PHYSICAL ILLNESS
STRESS AND CARDIOVASCULAR DISORDERS
How could stress contribute to these disorders???
(1) Direct Mechanical Effects = stress response increases blood pressure by contrictions of blood vessels
and increased heart rate... can wear away lining of blood vessels...
(2) Energy Mobilisation = two pathways lead to energy reserves being mobilised in for of fatty acids
and glucose... if these are not burnt up the body will attempt to reabsorb them into storage cells... is stressor is long-term
the body can't manage this... high levels of fatty acids and glucose remain in bloodstream...
Theorell & Emlund -> looked at effects of negative life events over one year.. these events were accompanied
by high blood pressure and production of fatty acids.
Evans -> found a link between low-status jobs and high blood pressure + cholesterol levels..
Cobb & Rose -> found that hypertension rates were several times higher in air traffic controllers..
KEY STUDY : The Western Collaborative Group Study
Aim to investigate links between the Typa A behaviour pattern and heart disease.
Proc interviews... 3200 california men (aged 39-59) were categorised (type A, X or B)... large sample
followed up for 8 and a half years to assess their life style + health outcomes.
Find 257 men had developed heart disease (70% were type A)... independent of lifestyle factors such
as smoking and obesity...
Conc type A increases vulnerability to heart disease... behaviour modification programmes to reduce
type A behaviour should reduce risk of heart disease...
Crit other variables could have affected vulnerability (eg hardiness)... not an experimental study
- cause + effect cannot be assumed... other studies failed to show a relationship between type A and heart disease...
Contribution of other factors!!!
Inherited : heart disease + high blood pressure may be partially genetic... family history studies
show pattern of high blood pressure in relatives...
Lifestyle : (1) smoking (2) poor diet (3) lack of exercise (4) obesity. HOWEVER, these lifestyle choice
are often the result of stressors.
Protective : (1) exercise (2) good genes (3) high level of control (4) good relationships/support
CONCLUSION TO STRESS + CARDIOVASCULAR DISORDERS = the evidence for a link between stress and cardiovascular
disorders is not simple + clear cut.... some studies have not been supported by other research evidence.... may be due to
difficulty of measuring vague concepts (stressors and personality types).... weight of evidence does suggest a link!!....
stress is one factor that interacts with others to cause heart disease..
STRESS AND THE IMMUNE SYSTEM
The immune system is our main defence against infection.
Non-Specific Immunity = PHAGOCYTES surround and eat foreign particles.
Cell-Based Immunity = LYMPHOCYTES called T cells seek out and destory foreign or infected cells (NK
cells do a similar job).
Antibody-Based Immunity = another type of LYMPHOCYTE - B cells seek out invading agents while they
are still in bloodstream. They produce antibodies which attach to foreign cell and slow it down so it can be destroyed by
other immune cells.
NOSE DROPS study
Aim investigate link between stressful life evenst and vulnerbility
to common cold.
Proc 394 healthy people asked to assess own stress level using questionnaire...
given stress index on the basis of this... they were exposed to one of five comon cold viruses in form of nasal drops.
Find 82% of the p's became infected with the cold virus... this highly
correlated with their stress index (high stress index = more symptoms of infection).
Conc strongly suggest that high levels of stress suppress immune
function and leave a person more vulnerable to viral infection.
Crit + nice sized sample... + well-controlled study... - correlation
only (cause and effect uncertain).
KEY STUDY - NK KILLER CELL
Aim investigate whether stress of important exams has an effect on
the function of immune system.
Proc 75 med students... natural experiment... blood samples taken
(a) 1 month before exams (b) during exams... immune function assessed (NK cell activity)... questionnaire to assess psych
Find NK cell activity reduced in 2nd sample... NK cell activity most
reduced in p's who also reported high levels of life events and loneliness.
Conc exam stress reduces immune function leaving individual vulnerable
to infection... immune function also affected by psych variables.
Crit - correlational study. strong conc of cause and effect
cannot be drawn... + natural experiment. reasonable ecological validity. generalisation to be made with caution though...
CONCLUSION OF STRESS AND IMMUNE SYSTEM
the evidence for a link is not simple and clear cut... weight of evidence
does suggest a link between stress and immune system... other factors (eg life events) can affect whether or not we get sick...
also, whether the stressor is short-lived or not... at most stress is just one contributing factor to illness.
SOURCES OF STRESS
Life Changes - 1. Life Events
Holmes & Rahe observed in their patients that stress and poor health
seemed to be associated with certain life events.
The life events could involve change from a steady state (divorce).
Even positive events (marriage) seemed to be associated with stress.
Changed associated with life events absorb PSYCHIC ENERGY, leaving
less available to fight illness.
Social Readjustment Rating Scale (SRRS) with 43 life events.. each with
a value of how stressful it is (life change units). If you have 150+ points on the scale = STRESSED!
Evidence for life events
KEY STUDY - Rahe et al (american soldier study)
Aim investigate whether SRRS scores were correlated wih subsequent
onset of illness.
Proc 2500 male american soldiers... total SRRS score recorded...
next 6 months, detailed records kept of health... LCU's (life change units) were correlated with illness scores.
Find positive correlation of +0.118 between life changes and
illness... though small does indicate correlation... as LCU's increased, so did illness frequency.
Conc As LCU's were positively correlated with illness scores, experiencing
life events increased the chanceof stress-related health breakdown... As correlation not perfect, other factors must be contributing.
Crit - study doesnt take into account individual differences in reaction
to stress... - a correlation doesnt show cause and effect... - sample restricted to us navy personnel (ethnocentric and androcentric).
this reduces validity and makes it difficult to generalise to other populations.
Evaluation of SRRS scale
+ simple, straightforward. quick and easy to administer and score.
+ significant correlations between LCU and ill health (good predictor).
- not a strong correlation. weak link between stress and illness.
- causality. the link is correlational onlu.
- positive life events. the srrs does not distinguish between positive and
negative stressors. this theory assumes ANY life change is stressful and there is no evidence for this.
Life Changes - 2. Daily Hassles
Kanner et al said it is the less dramatic and everyday events that are most
stressful (stuck in traffic). He called these 'hassles'. There was another concept of 'uplifts' that make you feel good (good
Evidence for Hassles
Delongis et al gave a questionnaire to test whether life evnts or hassles
are a better indicator of ill health... also considered uplifts... stronger correlation between hassles and ill health than
there was between life events and ill health... no relationship between uplifts and health... concluded it is more the daily
hassles in life that cause stress rather than major life events.
Criticisms of Hassles
- research correlational.
- no account of individual differences.
Conclusion to life changes
enough evidence to conclude that life changes do cause us stress... however
we do need to keep in mind that research in this field is correlational and that individuals may respond differently
to life changes.
1. Lack of Control : when workload patterns are set by others this
can lead to a sense of helplessness... there are individual differences, though, with some people preferring to leave decision
making to others.
KEY STUDY - Marmot et al
Aim to investigate the association between workplace stress and stress-related
illness in male and female civil servants... focused on positive correlation between job control and stress-related illness.
Proc 10308 civil servants age 35-55 (67% men, 33% women)... longitudinal
study (3 years)... job control measured by self-repot survery and independent assessments (2 times)... records kept for stress-related
illness... correlated analysis - test association with job control.
Find low job control = 4 times more likely to die of a heart attack.
Conc illness increases as job control decreases.
Crit - investigator effects. observations made by managers could
be biased because they expect correlation... - cause and effect not known. no connection between lack of control and illness.
2. Environmental Factors : noise, temp, pollution, overcrowding.
Calhorn established a population of rats in an enclosure... plenty of food,
no predators, little disease... within 2 years the population had reached a steady 150 adults... reason = stress... poor maternal
behaviour + high infant mortality rate because of social interactions... male rats became more aggressive and attacked
+ killed baby rats.
careful in generalising results to humans.
3. Workload : occurs when there it too much to do meaning people
spend longer at work, or the work is too difficult... worker's perception important... work underload occurs when there is
not enough to do or the work is boring/simple.
johansson et al studied workers who fed timer into cutting machiens... work
= repetitive + monotonous + workers felt they could do little to change things... high blood pressure, high rate of stomach
disorders + headaches... study lacks control... cause + effect???... study doesnt isolate which factor is causing stress.
Conclusion to workplace stressors
difficult to pinpoint specific sources of stress and separate them from
other factors that might cause stress.
Friedman and Rosenman - 2 personality types :
Type A - hostile, competitive, sense of time urgency.
Type B - relxed, less ambitious, focus on quality of life.
Type C - hard working, conventional, sociable, avoid conflict.
KEY STUDY - The Western Collaborative Study (see heart disease section)!!
Evaluation of personality types
- difficult to categorise people into three types.
- correlations in research is never strong.
- Type A can be happy people.
- Type A combined with hostility may lead to heart disease and not Type
A on its own.
Kobasa argued that people differ considerably in their ability to cope with
Hardy people have following;
1. commitment - more involved in what they do and have direction in life.
find meaning in work and relationships.
2. challenge - view potentionally stressful situations as a challenge and
3. control - stronger sense of personal control. able to influence events
in their lives.
Criticised as hardiness is difficult to assess...control, commitment + challenge
never defined... participants in studies have been middle class white men... difficult to generalise.
No evidence that one gender has more external stressors than the other.
KEY STUDY - Frankenhaeuser et al
Aim to test different reactions of males and females in response
to an external stressor.
Proc urine samples taken for male and female students prior to them
sitting an exam and at intervals after the exam... adrenaline measured... natural experiment.
Find female students showed small increase in adrenaline levels with
their adrenaline level returning to normal quickyl after exam... males were opposite... performance in examination roughly
Conc women showed less psysiological arousal than men and this is
why women live longer and suffer less stress-related illness such as heart disease.
Crit - other variables might have affected stress levels (environment)...
- limited sample. students only. cant generalise.
Reasons for gender differences
Evolutionary : men evolved to fight and hunt for food which means
they are stressed and aggressive...women evolved to care for children making them calm and caring... explanation non-falsifiable
(cannot be disproved)... should look at today not past.
Biological : Hastrup et al found that oestrogen helps to lower the
stress response... in men testosterone may act to increase their stress response... studies of pre-pubescent boys and girls
have still found differences... stress reaction not explained purely in terms of sex hormones.
Lifestyle : males have less social support and more unhealthy habits...
but the gender gap is narrowing with more women smoking and drinking and men are starting to discuss emotions
Socialisation : women = emphasis on caring... men = competitive...women
less likely to be Type A and be hostile... supported by evidence - women with male jobs had a more 'male' stress response.
Physiological approaches to stress management focus on reducing the stress response using things
like drugs and biofeedback.
Psychological approaches to stress management focus on changing the way people think and improve
their coping skills, using things like stress-inoculation training and hardiness.
Two most commonly prescribed = benzodiazephines (anti-anxiety) and beta-blockers (reduce blood
Benzodiazephines, such as Valium, can be very effective in reducing stress and anxiety... they
appear to reduce the activity of the brain neurotransmitter *serotonin* and reduce brain arousal.
Beta-blockers, such as Inderal, directly reduce the activity in the sympathetic branch of the
ANS... they can therefore be very helpful against symptoms such as raised blood pressure and heart rate... the have been used
by musicians and snooker players.
Evaluation of Drugs
+ drugs are quick and effective.
+ drugs are readily available and there is a wide range.
- longterm use can lead to dependency... withdrawal symptoms can occur (headaches etc)... drugs should only
be used for a short time.
- drugs have side effects... Bz can cause drowsiness and affect memory.
- drugs only target the symptoms and not the real cause of the problem.
drugs are useful for short term crisis management... they have serious drawbacks... do not address source
of problem or teach people to cope.
uses recordings of the body's physiologica activity, such as heart rate... measured by electrodes on the skin
and monitored by a hand held device... patient encouraged to lower the physiological activity by various strategies, such
as relaxation... this approach seeks to make the patient able to control the stress response.
** Physiological signals recorded ->>> signals amplified and displayed back via a screen or headphones
->>> patient uses relaxing imagery etc to reduce signals. watching and listening to signals reduces tension **
Evaluation of Drugs
+ Brady = reported a study in which college students suffering tension headaches were given seven 50
min sessions of biofeedback, resulting in significant reductions in headaches.
+ Attanasio = found that it works well with children who see it as a game and are much more optimistic
of the results than adults.
+ Budzynski = found that regular biofeedback sessions helped people suffering from chronic muscle contraction
headaches, even three months later they had siginificantly reduced muscle tension and had fewer headaches than a control group.
- Masters at al = found that it was no more effective than muscles relaxation alone, this suggests that relaxation
training is essential, feedback may not be.
- It may be the sense of control that patients get rather than biofeedback which is beneficial.
- Holroyd and others have shown that simply believing that muscle tension is relaxed can lead to
a reduction in tension headaches.
difficult to say how effective biofeedback is, as it is hard to interpret results...
Davidson and Neale said, "there is only limited evidence that biofeedback has any specific effects other than
distraction, relaxation and instilling a beneficial sense of control."
progressive muscles relaxation and meditation.
learning about your bodily state and retraining your muscles to relax. meditation also involves a mantro that
focuses the person's attention inwards.
Cognitive-behavioural approaches aim to reduce the experience of stress by;
* helping people to perceive the situation accurately.
* improving coping skills by training and practice.
Meichenbaum's Stress-Inoculation Training
1. conceptualisation : clients encouraged to relive and analyse stressful situations... discussions
(individual or group) sharing experience can help achieve a greater understanding of the nature of stress and the client's
2. skills training and practice : clients can be taught specific and non-specific strategies of coping...
relaxation techniques help them to cope with the initial arousal effects... training helps reduce speciic demands... general
relaxation helps to limit stress-induced arousal.
3. real-life application : go out into the real world and put training to the test... contact with
therapist continued and follow up sessions provided if necessary.
Evaluation of Stress-Inoculation Training
+ targets symptoms and causes... clients using technique should get a clearer understanding of their own strengths
and weaknesses, by reviewing how they have coped in the past... more confidence to cope in future.
+ effective... meichenbaum has produced evidence to support this claim - in 1977 he compared the relative
benefits of stress inoculation training with desensitisation... patients who had both a phobia of rats and snakes were given
treatment for one of these phobias, with either training or desensitisation... both techniques were successful... however
training greatly reduced the non-treated phobia too... suggests that self-instruction easily generalises.
- very few controlled studies of this kind carried out... little emperical evidence.
- takes time, commitment and money... less useful for highly stressed people... also individuals differ
in how easy they cope.
- the way we cope reflects our personality traits... innate or learned... changing habits and behaviour may
be too difficult for some.
range of personal factors that protect people against negative effects of stress;
CHALLENGE, COMMITMENT, CONTROL (3 C's)
3 aspects of procedure to reduce stress;
1. FOCUSING : trained to spot signs of stress response (eg muscle tension).. allows them to identify stressful
2. RELIVING STRESSFUL ENCOUNTERS : clients analyse recent stressful situations and evaluate how well they
turned out... allows them to understand how they do cope at the moment.
3. SELF-IMPROVEMENT : clients encourages to take on challenges that they can manage before moving on to more
difficult problems... gives them sense of control and mastery, develop belief they can cope with life's challenges.
Evaluation of Increasing Hardiness
+ research evidence... KOBASA rated participants on the presence or absence of three factors; hardiness,
social support and regular exercise... when followed up and assessed the p's with no protective factors had more physical
and psychological illness... all 3 factors seemed important, but hardiness the most... SARAFINO reports that people who have
followed the programme do score higher on hardiness and report feeling less stress and have lower blood pressure.
- theoretical issues... difficult to separate the effects of 3 C's... some evidence for role of challenge
and commitment in reducing stress response... most evidence is for control.
- generalisability... supporting studies tend to use middle class businessmen... impossible to generalise
to a wider population.
- effectiveness and practicality... few supporting studies of its effectiveness... takes a long time, involves
huge commitment and motivation, and tries to change fundamental persnality traits.