Stress is a state of psychological and physical tension
Stress is a state of psychological and physical tension produced, according to the transactional model. Stress is believed to account for high levels of anxiety and depression. Stress may be also defined as a physiological reaction that affects the autonomic nervous system (ANS), causing changes in arousal, hormone secretion and general physiological alertness. Perhaps the most important early contributor to attempt to explain stress related illness was Selye. He carried out research investigating the effects on animals of a range of stressors such as heat, cold, infections of organic substances and surgery. Selye (1950) defined stress as “the non-specific response of the body to any demand”. In other words stress is generalised reaction to a demand placed in the body. Interestingly, the term “stress” had not been used in relation to behaviour until Selye (1936) suggested using it to describe what happened when an organism was exposed to a noxious (unpleasant) stimulus.
By the 1980’s it was generally accepted that stress could have various effect on people, including making them more vulnerable to physical illness and psychological disorders. There is good evidence that stress can directly produce changes in the immune system, and there is also reasonable evidence that stress can directly increase the probability that individuals develop various physical illnesses. Kiecolt-Glaser (1984) studied human responses to stress and how the immune system can be affected to try to establish a link between conditions of high and low stress. They decided to use examinations as the high stress condition. They took blood samples from medical students. Samples were taken one month before their final examinations and again on the first day of their final examinations, after the students had completed two of their examinations.
A key finding was that natural killer cell activity declined between the two samples. This finding suggests that stress is associated with a reduced of the immune system. Cohen (1993) demonstrated that stress reduces efficiency of the immune system. To investigate the link between them he asked 394 healthy individuals to complete a questionnaire that indicated how stressed they perceived themselves to be. Each participant was given a stress index. The participants were then exposed to low doses of the common cold virus. One third of them developed a cold and infection was highly correlated with their index score; the higher the stress index, the more likely they were to develop a cold. This study suggests that high levels of stress reduce immune function and make a person more vulnerable to viral infection. As recently as the 1950s, there was little scientific evidence to suggest that physical illnesses such as heart disease might be influenced by psychological factors. Many people suspected that there was a link between stress and CHD. It was in this context that two cardiologists, Meyer Friedman and Ray Rosenman carried out their research to show that heart disease depends on individual differences in vulnerability to stress.
Friedman and Rosenman introduced a new “typology” to psychology in the 1950’s. They proposed that there were three personality types: type A are competitive, ambitious, impatient, restless, and pressured. Type B has lack these characteristics are is generally more relaxed. Types Cs are nice, industrious, conventional, sociable but tend to be repressed and react to stress or threat with a sense of helplessness. Early research findings showed a clear relationship between Type A behaviour and coronary heart disease. Strong evidence came from the Western Collaborative Group Study (WCGS) (Rosenman 1964), which was a prospective long-term study using the Structured Interview (SI) to assess Type A Behaviour (TAB) in more than 3,000 white middle-class males in non-manual occupations. When recruited into the study, none of the participants showed any signs of CHD. The participants were then followed up for eight and a half years during which time men who were classified as type ‘A’ were found to be twice as likely to develop CHD than those categorised as type ‘B’.
Other research has looked at a possible link between Type C and cancer. Morris (1981) proposed that the likelihood of developing cancer may be related to Type C behaviour, because such individuals tend to deal with stressful events by repressing their emotions. To study this, Morris interviewed 50 women being tasted to see if a breast lump was malignant (cancerous) or benign (non-cancerous). The patients were assessed to determine their typical patterns of emotional behaviour using questionnaires and interviews. Morris found that those found to have a malignant lump had reported that they both experienced and expressed far less anger than those with a benign tumour. This supports the idea of a link between cancer and the suppression of anger. Emotional suppression is associated with increased stress, lowered effectiveness of the immune system and illness. Supporting evidence was given in a study by Thomas and Duszynski (1974) who followed 1000 medical students over 15 years, finding that those who developed cancers also reported less family closeness. This may be due to stress, because people with poor social support system suffer greater stress.
According to Kobasa (Kobasa and Maddi), the concept of hardiness (or the hardy personality) is central of understanding why some people are vulnerable to stress and some resistant. Hardiness includes a range of personality factors that, if present, provide defences against negative effect of stress. These factors are: commitment- including people who are more involved in what they do and have a direction in life. Control is the belief that you have control over what happens in your life. Another factor is challenge, which tells that challenges should be overcome or seen as opportunities, rather than as threats and stressors. Kobasa has presented evidence that people who have high scores on scales measuring hardiness are significantly less likely to suffer stress-related physical and psychological disorders than those with low hardiness scores. In theory, their positive approach means that life events are not seen as stressful, but as challenges and opportunities that can be overcome.
There are evidences that women’s reaction on stress is different than men’s. Women’s responses are “tend and be friend”, because they are actively seeking social support from others. Men react with the “fight or flight” what makes them to be more likely harmed by stress. The gender difference could be also down to a hormone-oxytocin. Oxytocin is released during the stress response, making people feel less anxious and more sociable. Its effects are increased by oestrogen but decreased by male hormones Stone (1990) found that women shoed smaller increases in blood pressure than men when performing stressful tasks. In similar fashion, Frankenhaeuser (1976) found that boys showed a faster increase in stress hormones than did girls when taking an examination. In addition, the level of stress hormones returned to normal faster in girls than in boys. There are other important physiological differences between men and women. Another evidence for gender differences with coping with stress comes from Hastrup, Light and Obrist (1980) who tested women’s cardiovascular (heart) reactions. The women had lowered stress responses when their oestrogen levels were highest. These suggest that the hormone oestrogen may have helped them to cope. So far as life style is concerned, men used to much more likely than women to smoke and drink heavily (Ogden, 2000). For example, in the UK in 1992, nearly 30% of men were found to be heavy drinkers of alcohol compare to just over 10% of women. These responses to stress both have the effect of shortening life expectancy.