STRESS MODELS
Throughout the twentieth century, stress models have varied in terms of their definition of ‘stress’, their emphasis on physiological and psychological factors, and their description of the relationship between the individual and their environment. Cannon’s ‘fight or flight’ model One of the earliest models of stress was developed by Cannon (1932). The ‘fight or flight’ model suggested that external threats elicit the ‘fight or flight’ response, increasing activity rate and arousal. These physiological changes enable the individual either to escape from the source of stress or fight. Cannon defined ‘stress’ as a response to external stressors that is predominantly seen as physiological . Selye’s general adaptation syndrome Developed in 1956, Selye’s general adaptation syndrome describes three stages in the stress process: ‘alarm’, which describes an increase in activity and occurs immediately the individual is exposed to a stressful situation; ‘resistance’, which involves coping and attempts to reverse the effects of the alarm stage; and ‘exhaustion’, which is reached when the individual has been repeatedly exposed to the stressful situation and is incapable of showing further resistance. Life events theory In an attempt to depart from models that emphasize physiological changes, the life events theory examines stress and stressrelated changes as a response to life change. Research has shown links between life events and health status, in terms of both the onset of illness and its progression (Yoshiuchi et al., 1998). These results were obtained using Holmes and Rahe’s (1967) ‘Schedule of Recent Experiences’ (SRE) – an extensive list of possible life changes or life events. These range in supposed objective severity from serious events, such as ‘death of a close family member’ and ‘jail term’, through more moderate events, such as ‘son or daughter leaving home’ and ‘pregnancy’, to minor events, such as ‘vacation’ and ‘change in eating habits’. Each event has a predetermined point score to reflect its impact, with the combined score reflecting the adjudged stress rating of the assessed individual. For example, ‘death of spouse’ would result in more changes to an individual’s life schedule than ‘trouble with boss’, and is therefore allocated a higher pointscore. The difficulty with this significance weighting is that it was
devised by psychologists, not the research participants. For example, whilst a divorce may be very stressful for one person, it might be liberating for another. The model of appraisal and transaction Both Cannon’s and Selye’s early models of stress presented it as an automatic response to an external stressor – a perspective that is also reflected in life events theory, with its use of expert rather than individual rating schemes. By contrast, more recent models allow for active interaction between the individual and external stressors, rather than passive response. This approach provides a role for psychological state. It is epitomized by Lazarus’s transactional model of stress and his theory of appraisal.
In the 1970s, Lazarus introduced the psychological dimension into our understanding of the stress response (1975; Lazarus & Cohen, 1973, 1977). He argued that stress involves a transaction between an individual and his or her external world, and that a stress response is elicited if the individual appraises an event as stressful. Lazarus defined two forms of appraisal:
1. Primary appraisal: the individual initially appraises the event in three ways – as (a) irrelevant, (b) benign and positive or (c) harmful and negative.
2. Secondary appraisal – the individual evaluates the pros and cons of his or her different coping strategies. So primary appraisal is essentially an appraisal of the outside world and secondary appraisal is an appraisal by the individual of himself
Throughout the twentieth century, stress models have varied in terms of their definition of ‘stress’, their emphasis on physiological and psychological factors, and their description of the relationship between the individual and their environment. Cannon’s ‘fight or flight’ model One of the earliest models of stress was developed by Cannon (1932). The ‘fight or flight’ model suggested that external threats elicit the ‘fight or flight’ response, increasing activity rate and arousal. These physiological changes enable the individual either to escape from the source of stress or fight. Cannon defined ‘stress’ as a response to external stressors that is predominantly seen as physiological . Selye’s general adaptation syndrome Developed in 1956, Selye’s general adaptation syndrome describes three stages in the stress process: ‘alarm’, which describes an increase in activity and occurs immediately the individual is exposed to a stressful situation; ‘resistance’, which involves coping and attempts to reverse the effects of the alarm stage; and ‘exhaustion’, which is reached when the individual has been repeatedly exposed to the stressful situation and is incapable of showing further resistance. Life events theory In an attempt to depart from models that emphasize physiological changes, the life events theory examines stress and stressrelated changes as a response to life change. Research has shown links between life events and health status, in terms of both the onset of illness and its progression (Yoshiuchi et al., 1998). These results were obtained using Holmes and Rahe’s (1967) ‘Schedule of Recent Experiences’ (SRE) – an extensive list of possible life changes or life events. These range in supposed objective severity from serious events, such as ‘death of a close family member’ and ‘jail term’, through more moderate events, such as ‘son or daughter leaving home’ and ‘pregnancy’, to minor events, such as ‘vacation’ and ‘change in eating habits’. Each event has a predetermined point score to reflect its impact, with the combined score reflecting the adjudged stress rating of the assessed individual. For example, ‘death of spouse’ would result in more changes to an individual’s life schedule than ‘trouble with boss’, and is therefore allocated a higher pointscore. The difficulty with this significance weighting is that it was
devised by psychologists, not the research participants. For example, whilst a divorce may be very stressful for one person, it might be liberating for another. The model of appraisal and transaction Both Cannon’s and Selye’s early models of stress presented it as an automatic response to an external stressor – a perspective that is also reflected in life events theory, with its use of expert rather than individual rating schemes. By contrast, more recent models allow for active interaction between the individual and external stressors, rather than passive response. This approach provides a role for psychological state. It is epitomized by Lazarus’s transactional model of stress and his theory of appraisal.
In the 1970s, Lazarus introduced the psychological dimension into our understanding of the stress response (1975; Lazarus & Cohen, 1973, 1977). He argued that stress involves a transaction between an individual and his or her external world, and that a stress response is elicited if the individual appraises an event as stressful. Lazarus defined two forms of appraisal:
1. Primary appraisal: the individual initially appraises the event in three ways – as (a) irrelevant, (b) benign and positive or (c) harmful and negative.
2. Secondary appraisal – the individual evaluates the pros and cons of his or her different coping strategies. So primary appraisal is essentially an appraisal of the outside world and secondary appraisal is an appraisal by the individual of himself
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