Maternal expressive suppression moderates the relations between maternal and child hair cortisol.

Self-reports and physiological indicators of stress such as cortisol levels are correlated in maternal and child samples. This relationship is likely to be influenced by maternal emotion regulation. Herein, we investigate the moderating role of maternal regulation strategies on the association between maternal and child hair cortisol levels. Mother-child dyads (N = 63, child mean age = 49.74 months) participated in the study. Hair samples were collected from mother and child, and cortisol was assayed. Mothers reported on their own emotion regulation strategies, namely expressive suppression and cognitive reappraisal. As expected, mother and child hair cortisol levels were significantly correlated. Interestingly, the relation between maternal and child hair cortisol was moderated by maternal suppression of emotion. Mother and child hair cortisol levels were related at low levels of maternal suppression, but not at higher levels of suppression. Maternal cognitive reappraisal of emotion was not associated with cortisol levels.