Glee in threes: Positive affect synchrony in parent-infant triads is moderated by maternal hair cortisol and parenting stress.

BACKGROUND: Positive affect synchrony, or the reciprocal exchange of positive affect during free play, can scaffold infants' socioemotional development. However, parental stress may compromise the expression and exchange of positive affect within families. The current study assesses whether parenting stress and hair cortisol are associated with positive affect synchrony during a triadic play interaction. METHOD: Within 70 different-sex dyads consisting of first-time parents and their six-month-old infants who participated in a four-minute laboratory-based free-play task, facial affect of each member of the triad was observationally microcoded at the second-by-second level. Hair samples were collected from mothers and fathers for cortisol assay, and parents completed a self-report measure of parenting stress. RESULTS: Using dynamic structural equation modeling (DSEM), we found positive between-level and within-level affect synchrony across all family members, with one exception: infants' affect did not predict fathers' affect at the following timepoint. Mother-to-infant affect synchrony was greater in mothers with higher hair cortisol. Similarly, mothers with higher parenting stress tended to have greater infant-to-mother affect synchrony, and had infants that displayed less overall positive affect across the interaction. CONCLUSION: We found evidence for bidirectional, time-lagged synchrony in the momentary positive affect of mothers, fathers, and infants. Maternal hair cortisol concentration and parenting stress seem to increase affect synchrony between mothers and infants- suggesting that parental stress may correlate with greater affective attunement, but less overall positive affect in infants.

Physical touch during father-infant interactions is associated with paternal oxytocin levels.

INTRODUCTION: Physical connection, particularly parent-to-infant touch, is critical for the well-being of infants and may support the development of the parent-infant bond. Physical touch has also been found to stimulate oxytocin levels. This study tested whether fathers' micro-coded touch behaviors during parent-child interaction predicted their subsequent oxytocin levels. We also compared two widely-used methods of oxytocin immunoassay that have been found to yield discrepant results in past studies. METHODS: Among 45 fathers and their six-month-old infants, we micro-coded paternal physical touch at 1/10 s intervals during a laboratory-based free-play interaction. Paternal oxytocin was measured via blood plasma and was processed both with and without the extraction step prior to immunoassay so that results from the two methods could be compared. RESULTS: Unextracted and extracted oxytocin were moderately correlated within our sample. Fathers who engaged in more playful proprioceptive touch showed higher levels of both unextracted and extracted oxytocin. Gentle affectionate touch and functional proprioceptive touch predicted higher unextracted but not extracted oxytocin levels. Fathers who did not engage in physical touch showed lower levels of both unextracted and extracted oxytocin. CONCLUSION: Results are consistent with previous work showing that physical touch, particularly playful proprioceptive touch, is associated with higher oxytocin levels in fathers. These results replicate previous research using unextracted oxytocin measurement, and extend this work, showing that many but not all associations hold when using the more rigorous method of extraction when measuring oxytocin.