Peer-reviewed article
Change in toddlers’ cortisol activity during a year in childcare. Associations with childcare quality, child temperament, well-being and maternal education
Kathrin Nystad, May Britt Drugli, Stian Lydersen, Ratib Lekhal, Elisabet Solheim Buøen ·
Summary
Written by AI, not yet AICS's view · claude-haiku-4-5-20251001This study followed 156 toddlers in Norwegian childcare over a year, measuring cortisol (a stress hormone) at three time points to understand how childcare affects their stress levels. Children showed rising evening cortisol levels throughout the year, suggesting accumulating stress, though stress levels remained higher in childcare than at home. Toddlers with higher well-being in childcare had lower overall cortisol and less stress increase over time, and less active children seemed to accumulate more stress during childcare days.
Key points
- Evening cortisol levels increased through the year in childcare, suggesting accumulating stress
- Afternoon cortisol levels in childcare remained above morning levels, but this pattern reversed at home
- Higher well-being in childcare was associated with lower overall cortisol levels and less increase in evening cortisol through the year
- Less active (less temperamentally active) toddlers showed higher evening cortisol levels, indicating stress accumulation during the childcare day
- Findings indicate childcare is demanding for toddlers even after extended attendance
Limitations
The study is observational and measures cortisol as a proxy for stress without directly assessing whether elevated levels are harmful or represent normal adaptation. The findings are specific to one country (Norway) and may not generalise to childcare systems with different structures, quality standards, or cultural practices.
Abstract
Elevated levels of the stress hormone cortisol have been found in toddlers in childcare. Measuring cortisol may provide an indication of children's experiences in childcare and help to adjust practices better to their needs. To the best of our knowledge, toddlers' cortisol levels in childcare have not yet been investigated longitudinally. Furthermore, it is unclear which child and childcare factors contribute to cortisol elevation in toddlers. Using linear mixed model analyses, we investigated the full-day cortisol activity (10.00 h, 15.00 h, 18.00 h) of 156 toddlers (81 female, 56 male) during a year in childcare (September, January, June). We also investigated child cortisol levels at home in January. In addition, we tested the relation between cortisol activity and changes in cortisol activity across the year and childcare quality, temperament, well-being in childcare, and maternal education. We found increasing evening cortisol levels through the year while controlling for age. Afternoon cortisol levels were stable, but above morning cortisol levels in September and January and only slightly below morning cortisol levels in June. At home in January, afternoon levels were significantly below morning levels. Higher well-being in childcare was associated with lower overall cortisol levels and less increase in evening cortisol levels through the year in childcare. Further, less active toddlers seemed to accumulate some stress during the childcare day, indicated by higher evening cortisol levels. Rising evening cortisol levels may indicate accumulating stress across the year. Results point toward childcare being demanding for toddlers and their need for consideration from caregivers and parents, also after a longer period of childcare attendance. The findings underline the importance of observing, promoting, and further researching children's well-being in childcare.