WHAT IS STRESS?
The term ‘stress’ means many things to many different people. A layperson may define
stress in terms of pressure, tension, unpleasant external forces or an emotional response.
Psychologists have defined stress in a variety of different ways. Contemporary definitions
of stress regard the external environmental stress as a stressor (e.g. problems at work),
the response to the stressor as stress or distress (e.g. the feeling of tension), and the
concept of stress as something that involves biochemical, physiological, behavioural
and psychological changes. Researchers have also differentiated between stress that is
harmful and damaging (distress) and stress that is positive and beneficial (eustress). In
addition, researchers differentiate between acute stress such as an exam or having to
give a public talk and chronic stress such as job stress and poverty. The most commonly
used definition of stress was developed by Lazarus and Launier (1978), who regarded
stress as a transaction between people and the environment and described stress in terms
of ‘person environment fit’. If a person is faced with a potentially difficult stressor such as
an exam or having to give a public talk the degree of stress they experience is determined
first by their appraisal of the event (‘is it stressful?’) and second by their appraisal of their
own personal resources (‘will I cope?). A good person environment fit results in no or low
stress and a poor fit results in higher stress.THE DEVELOPMENT OF STRESS MODELS
Over the past few decades, models of stress have varied in terms of their definition of
stress, their differing emphasis on physiological and psychological factors, and their
description of the relationship between individuals and their environment.Cannon’s fight or flight model
One of the earliest models of stress was developed by Cannon (1932). This was called the
fight or flight model of stress, which suggested that external threats elicited the fight or
flight response involving an increased activity rate and increased arousal. He suggested
that these physiological changes enabled the individual to either escape from the source
of stress or fight. Within Cannon’s model, stress was defined as a response to external
stressors, which was predominantly seen as physiological. Cannon considered stress to be
an adaptive response as it enabled the individual to manage a stressful event. However,
he also recognized that prolonged stress could result in medical problems.Selye’s general adaptation syndrome
Selye’s general adaptation syndrome (GAS) was developed in 1956 and described three
stages in the stress process (Selye 1956). The initial stage was called the ‘alarm’ stage,
which described an increase in activity, and occurred immediately the individual was
exposed to a stressful situation. The second stage was called ‘resistance’, which involved
coping and attempts to reverse the effects of the alarm stage. The third stage was called234 HEALTH PSYCHOLOGY