Morning-to-afternoon increases in cortisol concentrations for infants and toddlers at child care: age differences and behavioral correlates

Child Dev. 2003 Jul-Aug;74(4):1006-20. doi: 10.1111/1467-8624.00583.


This study examined salivary cortisol, a stress-sensitive hypothalamic-pituitary-adrenocortical (HPA) axis hormone in 20 infants (12 females; M age = 10.8 months) and 35 toddlers (20 females; M age = 29.7 months) in full-day, center-based child care. Samples were taken at approximately 10:00 a.m. and 4:00 p.m. at child care and at home. At child care, 35% of infants and 71% of toddlers showed a rise in cortisol across the day; at home, 71% of infants and 64% of toddlers showed decreases. Toddlers who played more with peers exhibited lower cortisol. Controlling age, teacher-reported social fearfulness predicted higher afternoon cortisol and larger cortisol increases across the day at child care. This phenomenon may indicate context-specific activation of the HPA axis early in life.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Child Behavior / physiology*
  • Child Day Care Centers*
  • Child, Preschool
  • Circadian Rhythm*
  • Female
  • Humans
  • Hydrocortisone / analysis*
  • Hypothalamo-Hypophyseal System / physiology
  • Infant
  • Infant Behavior / physiology*
  • Male
  • Pituitary-Adrenal System / physiology
  • Saliva / chemistry
  • Stress, Psychological / metabolism
  • Temperament


  • Hydrocortisone