The father-infant co-regulation and infant social proficiency with a stranger.

A growing body of knowledge is available on the father's instrumental role in the development of the child, but there is less data on the role he fulfills in preparing the child for challenging social encounters. The present study was designed to investigate the predictive value of the toddler's co-regulation with the father and the capacities the infant shows during a later encounter with a stranger, beyond the effect of the co-regulation of the toddler with the mother. Thirty-one toddlers were engaged in three interactions: with the mother, father, and a stranger. The order of the first two interactions was randomized, while the session with the stranger, which involved a game of peek-a-boo with an object, was always last. The sessions were videotaped and coded according the Early Interaction Scale (EIS) off-line by trained coders. The results indicate that the extent of the infant's proficiency in interacting with the stranger was predicted by his or her social proficiency and his or her co-regulation with the father, beyond the contribution of his or her proficiency and co-regulation with the mother.