Self-disclosure is associated with adrenocortical attunement between new acquaintances.

Adrenocortical attunement-similarity in hypothalamic-pituitary-adrenal (HPA) axis activity-has been well-documented in close relationships (e.g., between romantic partners, parents and children, and close friends). However, little is known about adrenocortical attunement during early relationship formation. In the current study, we examine dyadic adrenocortical attunement during a guided conversation in which two new acquaintances (N = 140 people, 70 dyads), who were university students or adults in the community, answered questions about themselves. Dyads were randomly assigned to answer questions designed to elicit dyad members to reveal a high or low amount of personal information (i.e., to self-disclose at high or low levels). We collected saliva samples (assayed for cortisol) before and after the conversation, and we coded behavioral self-disclosure-the extent to which people revealed their thoughts, feelings, and facts about themselves-during the conversation. As expected, dyads who were assigned to ask and answer high self-disclosure questions disclosed more than those assigned to ask and answer low self-disclosure questions. In addition, greater self-disclosure during the conversation was associated with greater similarity in cortisol change-that is, dyad members who revealed more about themselves experienced more similar cortisol changes in response to their conversation. This work reveals one social process through which adrenocortical attunement occurs during early relationship formation, and, in doing so, describes how our physiological functioning is linked to those around us-even people we have just met.

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.

Adrenocortical attunement, reactivity, and potential genetic correlates among parent-daughter dyads from low-income families.

Examining the multitude of influences on the development of adolescent stress responses, especially among low-income families, is a critical and understudied topic in the field. The current study examined cortisol attunement between adolescent girls and parents (mostly mothers) from predominantly low-income, single parent, ethnic minority families before and after an in-laboratory disagreement discussion task. The sample consisted of 118 adolescents (Mage  = 13.79 years, 76.3% ethnic minorities, 23.7% European Americans) and primary caregivers (Mage  = 40.62 years; Mdn yearly income = $24,000; 43.2% single parents; 50% living below poverty line). We investigated oxytocin receptor (OXTR rs53576) gene variations as a potential contributor to attunement within the dyad. Results showed that parents and adolescents showed stress system attunement across the disagreement task, but that parent and adolescent oxytocin receptor genotype did not impact attunement. Future studies should detail biological factors that contribute to the calibration of stress response systems of adolescents across a variety of samples, particularly those experiencing a combination of stressors.

The effect of a maternal history of childhood abuse on adrenocortical attunement in mothers and their toddlers.

We investigated circadian mother-child adrenocortical attunement in the context of a maternal history of childhood abuse (HoA). Mothers were screened after birth using the Childhood Trauma Questionnaire. Women reporting moderate or severe abuse formed the HoA group (n = 37; HoAG) and were compared with a non-maltreated comparison group (n = 45; CG). Three years later, cortisol awakening response (CAR) and diurnal slope (DSL) were assessed. Mother-child interaction was coded using the Emotional Availability Scales at 12 months of age. For the CAR, we found adrenocortical attunement only in the HoAG (2-way interaction: p = .004), particularly if mothers scored low on structuring (3-way interaction: p = .042) and children scored low on responsiveness (3-way interaction: p = .044). DSL-attunement was dependent on maternal sensitivity (3-way interaction: p = .012) and child involvement (3-way interaction: p = .012). In the context of a maternal HoA, it seems possible for mother-child-dyads to show less optimal interactional quality but be stronger attuned to each other biologically.

Neural correlates of parent-child HPA axis coregulation.

Parents and children have been found to show coordination or coregulation of the hypothalamic-pituitary-adrenal (HPA) axis. This coordination may be reflected in adolescents' neural activation to parent stimuli, particularly in regions of the brain associated with social information processing. This study reports on 22 adolescents (13 males, mean age 17years), recruited from a longitudinal study to participate in a functional MRI (fMRI) scanning protocol. Approximately 1.5years before the scan, these same adolescents participated in a family conflict discussion in the lab with both parents, and all three family members provided samples of salivary cortisol five times, before and after the discussion. Multilevel models found positive cross-sectional and time-lagged associations between parents' and youth cortisol. Empirical Bayes (EB) coefficients, extracted from these models to reflect the strength of the relationship between parent and adolescent cortisol, were tested in conjunction with adolescents' neural activation to video clips of their parents taken from the conflict discussion. For both mothers and fathers, youth who showed stronger cortisol coregulation with each parent (both in cross-sectional and time-lagged analyses) showed more activation to that same parent in posteromedial regions (precuneus, posterior cingulate, and retrosplenial cortex) that have been linked with social cognition, e.g. mentalizing about others' emotions. Youths' adrenocortical coregulation with their parents may be reflected in their neural processing of stimuli featuring those same parents.