the effect of daily hassles on salivary cortisol levels, it was observed that cortisol
levels were not significantly related to hassles earlier in time, even those reported to
have occurred within 2 h of the cortisol measurement; however, cortisol was signif-
icantly elevated during current or anticipated hassles (Smyth et al. 1998 ). In studies on
occupational groups in Hawaii (school teachers and hotel workers), Brown and col-
leagues found low, or even negative, correlations between biological markers of stress
and self-reports, as shown in Tables7.1and7.2(Brown unpublished data). The
biological markers consisted of urinary levels of epinephrine and norepinephrine
measured during work hours, and the variance in ambulatory blood pressure values
(systolic and diastolic blood pressure, respectively) taken at 20 min intervals during
work hours, while the self-reports consisted of the“psychological demand”portion of
the job content questionnaire (Karasek and Theorell 1990 ), and the score on a life
satisfaction survey which records a person’s desire to make changes in their life
(James et al. 1987 ).Therewerenosignificant correlations between the ambulatory
blood pressure and urinary catecholamine measures. Among the school teachers, there
were significant correlations between job content questionnaire scores and the life
satisfaction survey, as well as between ambulatory blood pressure variability and
scores on the job content questionnaire.
For the same two studies in Hawaii, there were much stronger relations between
the ambulatory blood pressure readings and diary reports of negative moods
(anxiety, anger, or sadness). In the study of hotel workers, both systolic and
diastolic blood pressure were significantly elevated at times when people reported
negative moods in their diaries; e.g., at work, an individuals’Z-scores of systolic
(two tailedttest,t= 6.2,p< .001) and diastolic BP (t= 3.7,p< .001) were sig-
nificantly higher at times when a negative mood was reported (Brown unpublished
data). Similar results were found in the school teacher study; e.g., at work,Z-scores
for systolic (t= 4.9,p< .001) and diastolic (t= 4.0,p< .001) blood pressure were
elevated at times of negative mood reports (Brown et al. 2003 ).
The poor correlation among many stress measures is due in part to the complex
nature of stress, and the time course of the responses being measured. Table7.3
shows an approximate time line for stress measures including time to response as
well as whether the response is stable or variable over the time course of extended
exposure to stress. The table makes clear why correlations between stress measures
are often quite low: the measures are evaluating conditions at different times or
durations during aprocessof response to a stress. The biological response to stress
changes over time, with different aspects of the response changing in different ways.
In simple terms, a major difference is in whether one is measuring an acute stress
response—and thus the alarm reaction, or a chronic stress response—and therefore
the stage of resistance in Selye’s model. This also brings the problem of under-
standing just what the experience of stress means. If someone exhibits a biological
response indicative of stress but does not report feeling stressed, is she actually
experiencing stress? If someone reports feeling stressed but does not exhibit a
biological stress response, is she under stress? There are no simple answers to these
questions, which need to be addressed within the specific circumstances of a given
study.
124 D.E. Brown