Twenty-three persons participated in a study examining the relationship between daily stressors and daily fluctuations in cortisol. For 21 days, the participants completed the Assessment of Daily Experience scale, which yielded frequency and intensity stress scores and gave an indication of the subjects' perceptions of their control over the daily stressors. Nightly urines were collected and assayed for cortisol. The prospective design of the research allowed the authors to examine individual differences in cortisol over time as well as the often-studied pooled differences. Results from pooled and individual data showed that the intensity of the worst daily stressor was a significant but modest predictor of daily cortisol. The authors concluded that the relationship between cortisol and psychological events for pooled data is small because of the wide variability in individual responses.
Adolescent Adult