Infant affective responses to mother's still face at 6 months differentially predict externalizing and internalizing behaviors at 18 months

This study investigated (a) stability and change in infant affective respon ses to the still-face interaction, (b) whether maternal depression affected infant responses, and (c) whether responses to the still-face interaction predicted toddler problem behaviors. Infants (63 girls and 66 boys) of Euro pean American mothers (67 depressed and 62 nondepressed) were observed in t he still-face interaction at 2, 4, and 6 months. Affect and gaze were coded on a 1-s time base. There were stable individual differences in gazing awa y and in rates of negative affect. Developmental change occurred only for g azing away, which increased. At 18 months, infants who failed to smile at 6 months in the still-face interaction showed more externalizing-type behavi ors than did other toddlers. Infants who failed to cry at 6 months showed f ewer internalizing-type behaviors. Mothers' current depressive symptoms and infants' earlier responses to the still-face interaction made independent, comparable contributions to problem behaviors at 18 months.