Family alliance and infants’ vagal tone: The mediating role of infants’ reactions to unadjusted parental behaviors

We investigated the influence of family alliance on infants’ vagal tone. Physiological studies have shown that the quality of mother–infant interactions can influence infants’ vagal tone, which is an important indicator of emotion regulation. Although research has shown that family‐level relationships have a unique impact on child development, little is known about the association between the quality of mother–father–infant interactions and infants’ physiological regulation during a family interaction task. We hypothesized that infants in families with a greater family alliance, that is, degree of coordination reached by parents when completing a task, will have higher vagal tone than will infants in families with a lower family alliance. We also hypothesized that this association would be mediated by the amount of intrusive and withdrawn parental behaviors and by the impact of these behaviors on the infant during mother–father–infant interactions. This study included 82 parents with their 3‐month‐old infants. Results showed that family alliance was associated with infants’ vagal tone during triadic interactions and that the impact of intrusive/withdrawn parental behaviors on the interaction partially mediated this association.