The Pituitary-Adrenal System
- Brain senses a stressful situation. Instructs Hypothalamus to release corticotropin releasing factor (CRF) to the Pituitary Gland.
- The Pituitary Gland releases hormones into the bloodstream.
- ACTH travels to the Adrenal Cortex and stimulates the release of hormones called corticosteroids into the bloodstream.
- They have a range of effects on the body.
The Sympathomedullary Pathway
- The hypothalamus activates the adrenal medulla. The adrenal medulla is part of the autonomic nervous system (ANS).
- The adrenal medulla secretes the hormone adrenaline. This hormone gets the body ready for a fight or flight response. Physiological reaction includes increased heart rate.
Adrenaline creates changes in the body such as decreases (in digestion) and increases (sweating, increased pulse and blood pressure).
Effects of Stress on the Immune System
- Infection and diseases - Stress causes physiological changes that often weaken the immune system. As a result infections and illness occur more frequently.
- Indirect effects - Stress causes the release of ACTH from the pituitary gland in the brain, which signals the adrenal glands to release anti-inflammatory hormones. These inhibit immune cell functioning.
- Psoriasis and eczema - Symptoms of inflammatory skin disorders worsen in stress. Stress interferes with the immune system's ability to deal with the inflammation.
- YOU MUST CONSIDER OTHER FACTORS WHICH COULD CONTRIBUTE TO A PERSON'S POOR IMMUNE SYSTEM.
e.g. smoking, drinking excessive alcohol, drug abuse, poor diet and lack of exercise.
Age and gender differences in the effects of stres
A telephone survey of over 1000 adult Americans found that:
- women were significantly more likely to report problems and being stressed than men (84% vs 76%).
- people under the age of 65 were more likely to report problems and being stressed than older people (82% vs 70%).
However this survey does not tell us how these individuals are dealing with stress and how this stress impacts the immune system.
The Social Readjustment Rating Scale (SRRS)
The major way to measure the relationship between life changes and wellbeing is the SRRS. To create this scale Holmes and Rahe compiled a list of major life events then asked hundreds of men and women, of varying ages and backgrounds, to rate the events in terms of the amount of readjustment they would require. The death of a spouse came to and was given a 'Life Change Unit' (LCU) of100 and lower ratings such as a holiday gaining 13 LCU.
Once the scale was created participants were asked to mark off any of the 43 life events they had experienced in a period of time (often previous 2 years).
These scores were added together to work out the stress in a person's life. Holmes and Rahe proposed that a score of 150 or more increased the chances of stress related heath breakdown by 30%. I score of over 300 increased the odds by 50%.
Evaluating Life Changes
Individual Differences - The values on the scale will vary from person to person. some people may dislike Christmas and holidays so they would be higher on their list of stressors. Others may find separation from a partner as a relief and would have it lower in their scale of stressors.
Causality - The relationship between SRRS and health is completely correlational and tells us nothing of causality. Depression or chronic illness may lead to to life problems rather than be caused by them.
Positive life events - Some life events are positive. People getting married probably see it as a positive life change where 'change in financial state' could be taken as positive or negative. The SRRS does not distinguish between positive and negative stressors.
Self-report - Self reports are often affected by Social Desirability Bias making them very unreliable.
Dated and androcentric - Although it generated a huge amount of research in the 30 years after its publication, SRRS is now outdated and androcentric (focused on men e.g. 'wife stops or starts work').
Daily hassles are minor events that will arise in the course of a normal day. For example, daily commute to college, concerns with work, missing the bus. Some of these things may be fairly routine occurrences while others may be fairly unexpected. The hassle and its associated emotional effects often disappear after a short period of time.
Gervais, found that daily uplifts - positive daily experiences - began to balance the stress that accompanied the daily hassles.
Why are daily hassles so stressful?
- Minor daily stressors affect wellbeing by accumulating over a series of days to create persistent irritations, frustrations and overloads which result in more serious stress reactions, such as anxiety and depression. Many researchers say that the frequency and type of daily hassles experienced by individuals provide a better explanation of physical and psychological health than rare major life events.
- Often daily hassles arise from pre-existing chronic stressors and so amplify the effects of that existing stressor.
Evaluating Daily Hassles
- Causality - Most of the data on daily hassles is correlational, this means we cannot draw causal conclusions about the relationship between daily hassles and stress-related problems. However, these correlations do indicate that the daily stress in our lives can potentially have adverse effects on our health and feelings of wellbeing.
- Cultural differences - Social support is an important protective factor against stress, and there are clear cultural variations in how it is used. Researchers have looked into the way in which different ethnic groups use social support as protection against stressors, including daily hassles. Kim and McKenry (1998) looked at social support networks in a range of ethnic groups in a range of cultural groups living in America. They found that African-Americans, Asian-American and Hispanics all used the social support offered by significant others (e.g. parents and friends) more than White Americans did.
However, this is not always the case. Sim (2000) found that Korean early adolescents reported having more daily hassles that contributed to maladjustment than they had social support from significant others. There appears to be cross-cultural research supporting the claim that daily hassles contribute to health and social problems.
Sources of stress in the workplace
- Physical environment - Space, temperature, lighting etc. can all affect the individual. Physical stressors make work more difficult, and more energy has to be expended to overcome them. The increase in arousal can also lead to frustration, and many studies have shown that increased temperature and exposure to intense noise can lead to stress and aggression.
- Work overload - Overload is frequently reported as one of THE most stressful aspects of the workplace, and a key element in this is the impact long hours have on the family life (the home-work interface).
- Role ambiguity - This occurs when the requirements of a particular work role are unclear or poorly defined, and is a major factor contributing to work-related stress. This sometimes results either from having no clear guidelines separating one role from another, or ones that are contradictory.
Evaluating Workplace Stress
- Extraneous variables - Despite the apparent link between lack of job control and stress-related illness found in many studies, it is possible that important variables, such as personality, were not controlled for. It could be that people with Type A personality are attracted to stressful jobs and this is what causes their health problems rather than lack of job control.
- Job control - Having higher levels of job control can be stressful for some people. Schaubroeck et al. (2001) found that employees who had control over their job responsibilities but didn't have confidence in their ability to handle the demands of the role or who blamed themselves for negative outcomes were more likely to experience stress.
- Individual differences - Reasearch has shown that as other cultures take on the working practices of the West, a similar relationship between lack of control and stress-related illness is becoming evident. However, not all workers with low-control and high-demand jobs become ill.
Personality factors: Type A
The Type A behaviour pattern is often linked with Coronary Heart Disease (CHD), a stress related illness. It is often characterised by constant time pressure, doing several things at once, being intensely competative in work and social situations, and easily being frustrated by the efforts of others.
Williams et al. (2003) found that individuals who exhibited Type A personality were unhealthier than others, with hostility and impatience putting individuals at increased risk of developing high blood pressure - a major precursor th heart attacks, strokes and other symptoms of CHD.
A study over 300 German managers (Kirkaldy et al. 2002) compared managers with Type A behaviour who also had an external locus of control (likely to believe in bad luck and fate) with managers who had Type B behaviour and an internal locus of control (likely to believe they are in control of their own destiny. They found that those with a Type A behaviour and external locus had higher percieved levels of stress, lower job satisfaction and poorer physical and mental health than those with Type B behaviour and internal locus.
Explaining and Evaluating Type A and CHD
Type A's react to stressful situations quicker and stronger, causing increased heart rate and blood pressure. As a result the cardiovascular system is under a lot more wear and tear making them more susceptible to heart disease. Evaluation of Type A behaviour:
- Lack of consistent research support - Retrospective studies (looking at the previous behaviour of patients with CHD) and some prospective (measuring Type A behaviour using questionnaires and following the participants' health over the next months/years). Significant correlations have been found, but these are never very high, and many negative findings have been reported. Even the Type A concept has been questioned.
- The role of hostility - When high levels of hostility are combined with other high levels of Type A behaviour, correlations with CHD are significantly increased.
- Type A and hardiness - Many individuals with Type A behaviour survive quite happily with their pressured and competitive lives. Key factors in managing stress are a strong sense of commitment, control and challenge which creates a 'hardy personality'. A hardy personality is believed to play an important role in resistance against the damaging effects of stress.
- Protective factors - Along with factors which make them vulnerable, such as haste, time pressure, multi-tasking and hostility, a person with Type A behaviour may also possess many protective factors, such as control and commitment. there are also less specific elements that have been shown to protect against stress, such as physical exercise and social support. These may also help the Type A person to avoid the negative effects of stress.
The 'hardy personality'
Kobasa and Maddi 1977 - the concept of 'hardiness' is central to understanding why some people are vulnerable to stress and some are vulnerable. Hardiness includes a range of personality factors that defend against the negative effects of stress:
- Control - The belief that you can influence what happens in your life, rather than attributing control to outside influences. This is similar to an Internal Locus of Control.
- Commitment - The sense of purpose and involvement in the world around you. The world is seen as something you feel you can engage in rather than to stand apart from. Committed people tend to resist giving up in times of stress.
- Challenge - Life changes are percieved as challenges to overcome rather than threats or stressors. People who possess this factor do not seek comfort and security as their main goals, but rather look for growth and change.
Kobasa also identified that physical excersize and social support also protect against stress-related illness.
- Participants - Most of Kobasa's work was carried out on male, white-collar workers, and so the findings may not be generalizable to other groups. For example, stressors and coping responses differ between men and women.
- Components of personality - control, commitment and challenge have never been very clearly defined, so control, for instance, may be an important part of commitment and challenge rather than being seperate from them.