Emotion dysregulation is a core transdiagnostic risk factor for psychopathology and adolescence may be a sensitive period for the development of emotion regulation. Mothers may socialize emotion dysregulation by engaging in frequent interactions with their adolescents that involve mutual increases in arousal. This study examined mother-adolescent mutual arousal escalation in a conflict discussion task in adolescent girls. Further, we tested associations between mutual arousal escalation and adolescent emotion regulation. Participants comprised 84 adolescent girls (Mage=12.3[0.78]; 69% White) and their biological mothers. Dyads completed a 5m conflict discussion task, during which skin conductance level was collected as a measure of arousal. Adolescent emotion regulation outcomes included self-reported rumination and problem-solving, arousal habituation to a stressful speech task, and real-world use of positive and negative emotion regulation strategies. Multilevel models for distinguishable dyads indicated a significant random effect of time, with individual differences in arousal slope throughout the task for both adolescents and mothers. There were significant fixed and random effects of mother-to-adolescent cross-lagged arousal, indicating that mothers “transmitted” arousal to adolescents on average, and there was significant dyadic variability. Dyadic mutual arousal escalation predicted adolescent rumination, indicating that for dyads high in mutual arousal escalation and high in mutual arousal de-escalation, adolescents reported higher rumination. Mother arousal slope during the conflict task significantly predicted adolescent physiological regulation during the speech task; as mothers exhibited higher slopes on the speech task, adolescent slopes on the speech task were higher, reflecting less habituation. Higher mother-to-adolescent arousal transmission was associated with more use of positive and less use of negative emotion regulation strategies in the real world. Results suggest that mother-adolescent dyads vary in the degree to which they mutually escalate or de-escalate in arousal during stressful interactions, and in the degree to which mothers “transmit” arousal to adolescents. These differences in interaction style appear related to adolescents’ abilities to regulate their emotions. Adolescents in dyads who mutually escalate or de-escalate in arousal report more rumination, which may be indicative of a practiced dysregulatory response in stressful contexts (escalation) or a tendency toward cognitive processes that lead to withdrawal from aversive environments (de-escalation)
