This study investigates the caregiver–child relationship as a proximal risk factor in the transactional development of youth personality pathology. 129 girls (aged 11–13 years), two-thirds of whom were oversampled for shy and fearful temperament, and their primary caregiver, participated in laboratory-based conflictual interactions. Trained observers rated positive and negative escalation, mutuality, relationship quality, and satisfaction. Concurrently and two years later, girls’ maladaptive traits were assessed via self- and caregiver-reports based on the DSM-5 Alternative Model for Personality Disorders (AMPD) domains (negative affect, detachment, antagonism, disinhibition, and psychoticism). Using a series of path models, we assessed whether dyadic interactions predicted changes in maladaptive traits. In dyads exhibiting reduced positive interaction patterns, specifically a lack of mutuality and relationship satisfaction, we observed increases in girls’ negative affect, detachment, disinhibition, and psychoticism. These patterns were more pronounced in girls’ self-reports. Negative escalation predicted girl- and caregiver-rated increases in antagonism. The study illustrates the importance of the caregiver–child relationship in the etiology of developmental personality pathology by establishing a link between observed caregiver–adolescent interactions and prospective changes in key domains of maladaptive traits. It expands the literature on dyadic interaction and developmental personality pathology to the dimensional framework of the AMPD.

Although ample research links social factors and suicidality, there remains a gap in understanding how distinct processes within social communication relate to suicidality. We demonstrate how reciprocity of eye-gaze and facial expressions of happiness differ during parent-adolescent conflict based on adolescents’ future suicidal ideation (SI). Facial affect analyses were based on 103 girls (ages 11–13; M = 12.28; 75% White) and their parents. Eye-gaze analyses were conducted in subset of these dyads (N = 70). Participants completed a conflict discussion during which gaze to their partners’ eyes was assessed using mobile eye-tracking glasses and facial affect was coded using FaceReader Observer XT. Adolescents’ SI was assessed 12-months later. Actor-partner interdependence models tested whether participants’ gaze and affect predicted their own and their partners’ gaze and affect one second later and if these intra and interpersonal dynamics differed based on adolescents’ future levels of SI. Girls from dyads with less parental reciprocity of eye-gaze and happiness reported higher levels of SI 12-months later. During early adolescence, girls whose parents reciprocate their eye-contact or positive affect less during conflict may be at heightened risk for SI. If replicated, social communication could provide a promising intervention target to reduce suicidality prospectively.