Health Psychology : a Textbook

takes into account physical activity levels (as this produces a similar response to the

stressor); and when the laboratory task involves active coping such as a video game

rather than a passive coping task such as the cold pressor task (i.e. placing the hand in

icy water). In addition, they argued that appraisal is central to the congruence between

laboratory and naturalistic measures and that higher congruence is particularly appar-

ent when the stressors selected are appraised as stressful by the individual rather than

identified as stressful by the researcher. This indicates that laboratory assessments may

be artificial but do bear some resemblance to real life stress.

Physiological versus self-report measures

Stress is considered to reflect both the experience of ‘I feel stress’ and the underlying

physiological changes in factors such as heart rate and cortisol levels. But do these two

sets of measures relate to each other? This question is central not only to stress research

but also to an understanding of mind/body interactions. Research has addressed this

association and has consistently found no or only poor relationships between physio-

logical and perceived measures of stress (see Focus on research 10.1, page 246). This

is surprising given the central place that perception is given in the stress response. It is

possible, however, that this lack of congruence between these two types of measures

reflects of role for other mediating variables. For example, it might be that physiological

measures only reflect self-report measures when the stressor is controllable by the indi-

vidual, when it is considered a threat rather than a challenge or when the individual

draws upon particular coping strategies.

THE INTERACTION BETWEEN PSYCHOLOGICAL AND

PHYSIOLOGICAL ASPECTS OF STRESS

Stress is generally considered to illustrate the interaction between psychological and

physiological factors. The psychological appraisal of a stressor is central to the stress

response and without appraisal physiological changes are absent or minimal. Further,

the degree of appraisal also influences the extent of the physiological response. However,

there is little research illustrating a link between how stressed people say they are feeling

(perceived stress) and how their body is reacting (physiological stress). It is likely that

the mind–body interactions illustrated by stress are dynamic and ongoing. Therefore,

rather than appraisal causing a change in physiology which constitutes the response,

appraisal probably triggers a change in physiology which is then detected and appraised

causing a further response and so on. In addition, psychological factors such as

control, personality, coping and social support will impact upon this ongoing process.

This psychophysiological model of the stress response is described in Figure 10.4.

TO CONCLUDE

This chapter has examined the different models of stress, the psychological and physio-

logical responses to stress and the way in which stress has been measured. Early models

248 HEALTH PSYCHOLOGY