Adrenocortical interdependence in father-infant and mother-infant dyads: Attunement or something more?

Father‐infant and mother‐infant (one‐year‐olds) adrenocortical attunement was explored during the Strange Situation Procedure (SSP) among 125 father‐infant and 141 mother‐infant dyads. Cortisol was assessed at baseline (T1), 20 (T2), and 40 minutes (T3) after the first parent‐infant separation. Initial correlations indicated significant associations between father‐infant and mother‐infant cortisol at each time. Cortisol interdependence was further explored using Actor‐Partner Interdependence Models. There was no evidence supporting cortisol interdependence based on within‐time residual correlations between parent‐infant cortisol, once stability and cross‐lagged paths were controlled. Infant cortisol at T2 predicted T3 cortisol for fathers and mothers resulting in a series of follow‐up exploratory analyses to examine mediating processes which revealed that infant distress during the SSP predicted infant T2 cortisol, which, in turn, predicted infant negativity during the 15‐min mother‐infant teaching task that followed the SSP. Among father‐infant dyads, infant T2 cortisol predicted infant negativity during father‐infant interaction, with infants expressing more negativity having less sensitive fathers. Findings provide little support of parent‐infant adrenocortical attunement across either father‐infant or mother‐infant dyads during the SSP, but preliminary evidence indicates infant distress as a potential mediator. Future research may want to focus on affective and behavioral processes that underlie the concept of parent‐infant adrenocortical attunement.