AS Module 2: Physiological Psychology and Individual

Differences

Topic 2: Sources of StressBy Dr George Varvatsoulias

The relationship between stress and cardiovascular disorders (Krantz et al.,

1991) (1)

AimsThis study investigated whether mental stress increases

myocardial ischemia. Also, it was investigated whether individuals with coronary artery disease (CAD) react differently from those with no cardiovascular problems

Procedures39 patients and 12 controls through three mental tasks:

an arithmetic task, a stroop task, and simulation of public speaking. Measurements included recording participants’ blood pressure, and the contraction (muscle compression) of the blood vessels around the heart

The relationship between stress and cardiovascular disorders (Krantz et al., 1991) (2)

FindingsPatients with greater myocardial ischemia during mental

tasks showed increases in blood pressure. Controls were showing lowest levels of myocardial ischemia and blood pressure during mental tasks. None or moderate indication of all the above was exhibited in some patients

ConclusionThere is a direct link between a stressful cognitive task

and physiological activity in relation to cardiovascular system. However, individual differences play an important role in responsiveness of tasks

The relationship between stress and cardiovascular disorders (Krantz et al., 1991) (3)

CriticismsEthical Issues: Mild stress for the purpose of study is

not acceptable here since participants were facing greater stress (being in the condition of a cardiovascular disorder)

Validity of the conclusion: The behaviour of the cardiovascular patients was also examined in relation to those without (controls); however, no comparison was tested in stress/no stress condition; in other words, stress performance might not be the cause for cardiovascular ischemia to those patients

Further research on stress and cardiovascular disorders (1)

Cardiovascular disorder and anger (an example of acute stress)

Williams et al. (2000) conducted a study on the relationship between anger and heart disease. 13000 people took part with no incidents of heart disease. Six years later, their health was checked: 256 had experienced heart attacks; those who scored higher on the anger scale were 2.70 more likely to have a heart attack, than those with lower anger ratings

Further research on stress and cardiovascular disorders (2)

Cardiovascular disorder and work-related stress (an example of chronic stress)

Russek & Zohman (1958) looked at heart disease in medical professionals. Two groups of high-stress and low-stress subjects. It was found that stress is linked to heart disease whether directly or indirectly

Further research on stress and cardiovascular disorders (3)

Cardiovascular diseases and individual differences

Rozanski et al. (1999) have found that the sympathetic branch in some individuals is more reactive than in others. Those described as hyperresponsive indicate that they respond to stress with greater increases in blood pressure and heart rate than others

The relationship between stress and the immune system (Kiecolt-Glaser et al, 1995) (1)

AimsInvestigating the direct effects of stress on the immune

system. There were sought participants with ‘natural’ levels of chronic stress, like caring for people with special needs

Procedures13 women in experimental group, 13 women in control

group. All participants were given a ‘wound’ which was treated the same to all of them. A second measure of immune response was taken. Levels of cytokines were assessed. Finally, participants were given a 10-item perceived stress scale to check how stressed they actually were

The relationship between stress and the immune system (Kiecolt-Glaser et al, 1995) (2)

FindingsParticipants who were carers needed less time

for their wound to heal than controls. Cytokine levels were lower in carers than controls. On the perceived stress scale, carers responded as feeling more stressed than controls

ConclusionChronic stress decreases the functioning of

immune system; the same was shown in cytokine levels

What are we going to learn today

Sources of stress in terms of life changes and workplace factors

Questions on sources of stress won’t include direct aspects, such as the work of Holmes & Rahe, or what is ‘workplace stressors’

Stress can affect everyone, but not in the same way. What is being asked is to know how the effects of stress might be modified by personality differences [e.g. Type A/Non-Type A/ Type T (‘thrills’, including both positive and constructive forces of creativity, as well as all negative and destructive choices in one’s life (Farley, 1990)]

Positive and negative stressors

All we understand about stressors are negative life events; however, positive life events, such as leaving home, starting a new job, going to University, or getting married, may also have a stressful impact in one’s life, because of...

Not fully understanding the perceived demands of involving ourselves in sources of stress, leading to...

Physical, mental, and emotional exhaustions, known as burnout/examples from professions include teachers, nurses, police officers, etc.

Living in ghettos can also be a measure of stress for illnesses, such as hypertension

Things we need to know before discussing sources of stress

Stress as a cognitive appraisal (how a stressful situation can be understood) for the life of individuals. How a stressful life event is examined before even has started (prior to become an ‘accomplished fact’)

The relationship between stress and stressor is not particularly clear. Personality, culture, and gender influence how stress is perceived. The hormone oestrogen helps pre-menstrual women not to develop cardiovascular diseases, whilst those who had their ovaries removed may be in greater risk. Are women less likely to develop a Type A personality compared to men?

Women and stress

Although women seem to live more years than men, the lifestyle they follow many times is similar to that of men. The numbers in men and women suffering from cardiovascular diseases is somehow similar, and this because women have also developed a Type A personality: smoking, drinking, entering the workforce, being simultaneously a wage earner and a mother does double the risk-chances of stress-related diseases

What do we mean by ‘life changes’

Life changes refer to events of different life states than those individuals used to know. Because the impact of those changes brings upon a considerable amount of cognitive and emotional involvement as how one adapts to them, they are stress-related

Life changes lead to stress: Holmes & Rahe (1967) observed that major life events precipitate physical illness. Every life event needs a ‘psychic energy’ to be expended, which means that individuals need to ‘release’ more effort from their body and mind expenditure reservoirs so to deal with it

The Social Readjustment Rating Scale (SRRS) as a measure of stress (1)

100       death of a spouse  73       divorce  65       marital separation  63       detention in jail or other institution  63       death of a close family member  53       major personal injury or illness  50       marriage  47       fired from work  45       marital reconciliation  45       retirement  44       change in health or behavior of family member  40       pregnancy  40       sex difficulties  39       gain of new family member through birth, adoption, or marriage  39       major business readjustment  38       change in financial state  37       death of close friend  36       change to a different line of work  35       change in number of arguments with partner  31       taking on a new mortgage  30       foreclosure on a mortgage or loan

29       change in responsibilities  29       son/daughter leaves home  29       trouble with in-laws  28       outstanding personal achievement  26       partner begins/stops work  26       starting or finishing school  25       change in living conditions  24       revision of personal habits  23       trouble with boss  20       change in working hours or conditions  20       change in residence  20       change in schools  19       change in recreational habits  19       change in church activities  18       change in social activities  17       major purchase such as a new car  16       change in sleeping habits  15       change in number of family gatherings  15       change in eating habits  13       vacation  12       Christmas or holiday observance  11       minor violation of the law

The Social Readjustment Rating Scale (SRRS) as a measure of stress (2)

Holmes & Rahe enlisted 400 participants, and asked them to score each event in terms of their perceived readjustment. The more readjustment would need the more it would receive a larger score (baseline figure was 50)

Scores then were totalled and averaged to produce Life Change Units (LCUs) for each life event

Life changes as a source of stress (Rahe et al., 1970) (1)

Aim- Rahe et al. employed SRRS to test Holmes et Rahe’s hypothesis that the

number of life events a person experiences would positively correlate to illness. Participants were coming from ‘normal population’, i.e. they hadn’t been registered as ill in hospitals

Procedures- The SRRS was given to US Navy Cruisers (2700 subjects). It was an

opportunity sample; they completed the questionnaire in around 7 months, noting all life events they experienced in the previous 6 months

Findings- A LCU score and an illness score were calculated for each man. The

positive correlation was supported – in other words, an increased relationship. Although the figure was .118 and not strong, because of the number of participants it was significant

Conclusions- The findings supported the hypothesis. Possible the link between the two is

stress; life changes cause stress, which means they refer to the overall psychic energy needed to deal with an event that results to stress

Life changes as a source of stress (Rahe et al., 1970) (2)

CriticismsUnreliable data: Recalling life changes may prove

inaccurate. Negative events are sometimes inhibited because individuals don’t want to remember them, or they may remember them not exactly

Is the SRRS a valid measure?: The major criticism about SRRS is that it is focused on acute life events rather than ongoing (chronic) ones. Desirable and undesirable events, or social resources are not taken into account. These are probably the reasons for the weak correlation found in the study

Research methods: Correlation coefficients

Research methods: Significant result and ‘null hypothesis’

- A ‘significant result’ means we have a real association/correlation or difference in our findings, and that our hypothesis is accepted or can be refuted

- A ‘non-significant result’ means there is not enough correlation/difference, therefore we accept the ‘null hypothesis’/the variables under examination are not related

Correlation coefficients of illness score (1), and LCUs (2)

+0.91 & +0.63 mean that co-variables are closely correlated (1.0)

In the study by Rahe et al (1970) there was found 0.118 correlation/not so strong one; however since the sample was enormous (2700 respondents), the correlation is significant

In other words, the greater the sample the greater the significance even if coefficients are small. E.g. in a sample of 20 to 30 participants the greater the correlation (close to 1), the greater the significance. Whereas a large sample may have a significant correlation even with distance from 1.0

Ways in which life changes cause stress

Bereavement: meaning the loss of something valued, such as death, breaking up, loss of a job etc.

Post-traumatic stress disorder (PTSD): implying the cognitive and behavioural arousal involved in an exposure after a traumatic event took place, such as accident, violence, war. Subjects may relive that in the form of flashbacks, nightmares, etc.

Other ways in measuring life changes

Daily hassles: DeLongis et al. (1982) suggested that chronic stress may be also an everyday reality in terms of money, job, friends, sex, weather, etc.

Perceived importance: Moos & Swindle (1990) produced the Life Stressors and Social Resources Inventory (LISRES) for areas of ongoing stressors, such as health, home, finance, work, partner, child, extended family, friends

Other research on life changes as a source of stress

Life changes are related to physical health: Jacobs & Charles (1980) investigated life events and cancer in children. It was found that family stress was associated with child cancer more than in children who were treated in diseases other than cancer

Life changes are not related to physical health: DeLongis et al. (1988) studied 75 married couples. They found a significant positive correlation between hassles and next-day health problems, such as flu, sore throats etc., but no relationship between life events and health

Designing questionnaires

Clarity: Respondents should understand what is being asked without ambiguity

Bias: Avoiding question to the likeness of the experimenter; questions that are socially desirable and not reflecting the truth

Analysis: Questions should be easy to be analysed: open/close questions

A pilot study is preferable to a small number of participants so to be tested the validity of particular questions

Workplace stressors

Employees and employers are both affected by workplace stressors

Examples include: physical stressors (noise, length of working day, dangers at work), psychological stressors (relations with colleagues, role undertaken, issues of organisation)

A study of workplace stressors by Marmot et al., (1997)

(1)

Aims: Stress and illness in workplace come together because of high demands and low control in jobs. Employees with greater experience face higher demands in their jobs, whereas low-experienced ones face low job control

Procedures: 7372 people answered a questionnaire and checked for signs of cardiovascular disease. After 5 years each participant was reassessed for signs of cardiac disorder

A study of workplace stressors by Marmot et al., (1997)

(2)

Findings: Participants in the highest rank of their job experienced less cardiovascular problems; participants in the lowest rank have had weaker sense of job control. Cardiovascular diseases were developed in people who were under risky factors, such as smokers, being overweight

Conclusions: Higher stress is linked to low job control, whereas high job demand does not relate to stress and illness

A study of workplace stressors by Marmot et al., (1997)

(3)

Criticisms- Can the findings be explained in terms of

socio-economic status? People who have low socio-economic status are more likely to be found under risky factors. However, although the amount of stress in low control jobs is small, it can be an important factor in the workplace

- Biased sample: Not all individuals in all jobs are affected the same by workplace stressors

Factors in the workplace that act as stressors

Work overload- Repetitive tasks in high demand jobs can exert high-risk

influence to the workforce Lack of control- Perceived demands from the environment and the ability one to

cope with are interlinked when demands exceed perceived ability of coping

Role conflict and role ambiguity- Demands at work give rise to conflicts, whereas lack of knowing

job responsibility leads to frustration Environmental factors- Environmental factors at work increase aggression, and stress

(noise, hear, poor lighting, etc.) Galvanic skin response (GSR) and detection of stress

Individual differences and the role of personality

People are influenced or affected by stress in different ways. Individual differences in stress and stressors help us to understand in a more general view the human behaviour

Characteristic behaviours, attitudes, and general temperament distinguish one individual from another. As to that, we speak of personality traits that sometimes we share and some others we don’t

Research on the role of personality in modifying the effects of stressors (1)

Type A: Individuals are aggressive, ambitious and have an acute sense of time urgency (Friedman & Rosenman, 1959). 3000 men were examined in California for signs of CHD; in a way, provocative to the respondent, the interviewer spoke hesitantly and slowly, so to elicit participants to interrupt. After 8.5 years many Type A participants had died of cardiovascular problems (Type B/Non-Type A individuals lack the above characteristics)

Research on the role of personality in modifying the effects of stressors (2)

Type C: Those individuals suppress emotions, particularly negative ones; they are unassertive, and rarely get into trouble. Temoshok (1987) suggests that such individuals ignore their needs in order to please others, and that has negative consequences to them. Such behaviours attack the immune system and may be associated with the onset of cancer

Research on the role of personality in modifying the effects of stressors (3)

Type D: People who are gloomy, socially inept and worried may also be at risk of heart attacks, because they behave in a depressed or distressed manner. Denollet et al., (1996) first identified Type D having looked at 300 men and women who suffered heart attacks. The subjects proved to be socially alienated and associated with depressive feelings

Research on the role of personality in modifying the effects of stressors (4)

The hardy personality type: Kobasa (1979) proposed that some people are more psychologically hardy than others. Hardiness could be taught as a stress management technique comprised of:

1. Control: they control themselves rather than controlled by external factors

2. Commitment: they have strong sense of purpose; they take part; they don’t flee

3. Challenge: Life changes for them are challenges for the better; they enjoy new experiences looking at them as opportunities for further development

Effects of personality on stress

Are the effects of personality a cause or an effect? Greer et al. (1979) found that women with cancer had a fighting spirit and recovered from the condition quicker; in other words, personality characteristics may be a positive cause in fighting an illness

Are the effects of personality direct or indirect? A cause or a correlation? Nemeroff & Musselman (2000) found that there is a direct link between personality and illness. Some subjects because of suffering from sticky platelets (thrombocytes) were provided with ‘prozac’ and others with ‘placebo’ (being told it was Prozac). Although both groups were healed, it wasn’t for Prozac to be, but the mood itself as influencing subjects’ bodily systems

The role of gender in stress

Biological explanations: Less impact on stress is experienced by women whom levels of oxytocin (the anti-stress hormone) are higher than men (Taylor et al., 2000). Hastrup et al. (1980) found also that levels of oestrogen protect women more than men

Social explanations: Males have less social support, more unhealthy habits, and more stressful situations. Women engage in fewer unhealthy behaviours than men. However, since women entered the workforce they become as much stressed as men.

Cognitive explanations: Different cognitive appraisals between men and women irrespective of the effect of sex hormones. Vögele et al (1997) suggest that females learn to suppress anger and so show low reactivity, whereas males by suppressing anger it leads to raised blood pressure

Do females in fact react more than males?: Stone et al. (1990) had shown that higher reactivity to stressors (a video game and cigarette smoking) was observed more in women than men

Research methods: Interviews

Structured interviews: Questions are predetermined, and it is difficult for he interviewer to stick to its own script (foreseeing the answers without taking into account what his/her interviewees actually said)

Unstructured interviews: questions lack predetermination (in many cases), because they result from responses of the actual interview of his/her participant

Summary

Life changes influence the onset of stress and the emergence of illnesses

Workplace factors reveal a positive correlation between the experience of stressors and various cardiovascular diseases

Individual differences and personality characteristics play an important role in moderating life stressors

Gender differences affect the way both sexes consider stress socially

Essay questions

‘All employees suffer from some degree of stress as a result of their work’. Assess the relationship between stress and the workplace (12 marks)

‘Some personality types are more vulnerable than others to the effects of stressors’: To what extent is stress modified by personality type? (12 marks)

Describe two research studies into the effects of life changes as sources of stress (6+6 marks)

Few References

Greer, A., Morris, T., Pettingdale, K. W. (1979): Psychological response to breast cancer: Effect on outcome. The Lancet, 13, pp. 785-787

Holmes, T. H., Rahe, R. H. (1967): The social readjustment rating scale. Journal of Psychosomatic Research, 11, pp. 213-218

Kiecolt-Glazer, J. K., Marusha, P. T., Malarkey, W. B., Mercado, A. M., Glaser, R. (1995): Slowing of wound healing by psychological stress. The Lancet, 346, pp. 1194-1196