Children's cortisol response to the transition from preschool to formal schooling: A review.

This review examines the current state of knowledge regarding children's biological stress response during the transition from preschool to compulsory formal schooling, focusing on longitudinal studies that include repeated measures of cortisol concentrations in saliva or scalp hair. In all, eight independent studies (ten publications) were found and their results support the hypothesis that the transition from preschool to formal schooling coincides with an increase in cortisol concentration in both saliva and hair. Evidence of recovery (i.e. decrease in stress response over time) is more limited and suggests that it could take as many as 3-6 months before kindergarten children's cortisol concentration returns to baseline levels. However, important individual differences are observed. Potential predictors that have received some empirical support include child temperament (fearfulness/inhibition or surgency/extroversion) and prenatal maternal stress or anxiety. Very few studies, however, have examined whether there are actual functional consequences of individual differences in children's cortisol response associated with this transition. Finally, current methodological limitations and avenues for future studies are discussed.