Developmental change in infants' responses to stress

Child Dev. 1995 Jun;66(3):657-70. doi: 10.1111/j.1467-8624.1995.tb00896.x.


Infant stress responses to a well-baby physical examination and inoculation were observed longitudinally at 2, 4, and 6 months of age. In general, there were cortisol increases over base to the procedures. Cortisol level and cortisol response decreased with age. These data indicate a developmental shift in adrenocortical functioning between 2 and 6 months of age. Further evidence for this shift was seen in the stability of individual responses between 4 and 6 months of age. Individual differences in both cortisol and behavioral responses showed the most stability between these 2 ages. Moreover, diurnal variation in baseline cortisol level was present only at 6 months of age. While a sizable minority of infants showed stress-related cortisol decreases to the procedures at a given age, there was no evidence for cross-age consistency in individual infants showing these cortisol decreases.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Age Factors
  • Child Development*
  • Circadian Rhythm
  • Cross-Sectional Studies
  • Female
  • Humans
  • Hydrocortisone / analysis
  • Infant
  • Infant Behavior*
  • Longitudinal Studies
  • Male
  • Saliva / chemistry
  • Stress, Psychological / psychology*


  • Hydrocortisone