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Published on: July 10, 2017
Correlations between cortisol level and internalizing disposition of young children are increased by selecting
Ishien Li1, Hua-Huei Chiou, Pao-Sheng Shen
1Department of Child Care and Education, Hungkuang University, Taichung 43302, Taiwan. ishien@sunrise.hk.edu.tw
Insights
Optimal testing for personality and cortisol in children requires careful timing and multiple samples. Mid-afternoon cortisol measurements and aggregated data best reveal associations between personality traits and stress hormone levels.
Area of Science:
- Psychoneuroendocrinology
- Developmental Psychology
Background:
- Cortisol levels fluctuate throughout the day and across days.
- Understanding these fluctuations is crucial for accurately assessing the relationship between personality traits and stress in children.
Purpose of the Study:
- To identify the optimal sampling time and number of days for reliable cortisol measurements in preschoolers.
- To examine the association between personality traits and salivary cortisol levels in young children.
Main Methods:
- Ambulatory salivary cortisol sampling was conducted on 39 preschoolers.
- Sampling occurred at four different times daily for 10 consecutive school days.
- Repeated-measures ANOVA was used to analyze the data.
Main Results:
- Significant effects of day, time, and their interaction on cortisol levels were found.
- Cortisol levels differed significantly in early morning, early afternoon, and late afternoon, but not late morning.
- Mid-afternoon cortisol showed the strongest day effect and highest correlation with internalizing disposition.
- Increased data aggregation enhanced the probability of finding significant cortisol-personality correlations.
Conclusions:
- Mid-afternoon is a critical time for assessing cortisol-personality associations in preschoolers.
- Multiple sampling days and data aggregation are essential for reliable results.
- Careful selection of sampling time and sufficient data aggregation are vital to avoid underestimating cortisol-personality relationships.
Abstract:
To determine the optimal time for testing the association between personality traits and cortisol levels, and the number of sampling days needed for reliable results to be obtained for preschool-aged children, ambulatory salivary sampling for cortisol was performed on 39 preschoolers at four different times for 10 consecutive school days. A repeated-measure ANOVA revealed a significant day effect, time effect, and day by time interaction. Further tests of day effect revealed that within-subject cortisol levels differed significantly in the early morning, early afternoon, and late afternoon cortisol data, but not in the late morning; group average levels of cortisol assessed in the early mornings are significantly different among the days, so are the ones measured in early and late afternoon. Mid-afternoon cortisol levels showed the most significant day effect and the highest correlation with internalizing disposition. In addition, the probability of finding significant correlations between cortisol levels and internalizing disposition increased with a greater number of aggregated cortisol measures. The tentative conclusion is that to avoid under-representation of the correlations between cortisol levels and personality variables, both sampling time selection and data aggregation are important.
