Stable asynchrony? Association between borderline personality traits and interpersonal asynchrony

Interpersonal coordination processes facilitate interpersonal synchrony through a continuous mutual adaption and corepresentation of self and others’ actions. Such a process has been found to enhance prosocial behaviors, affiliation, and trust. While research has investigated the general underlying cognitive and social mechanisms that facilitate interpersonal synchrony, much less is known about how interpersonal impairments influence it in various psychopathological conditions—such as borderline personality disorder (BPD). In this study, we investigated the role of the social cognitive processes of individuals with high BPD traits during a synchronized interaction task. Participants (N = 206) were recruited from the general population. BPD traits were assessed, and interpersonal synchrony was measured with a finger-tapping task. Participants were instructed to interact with a virtual partner (VP) that varied its adaptivity level in response to their taps across different conditions of adaptivity (α), ranging from nonadaptive to overly adaptive. After each interaction, the perception of synchrony and affect were assessed. Results showed an overall main significant effect of the adaptivity of the VP on interpersonal synchrony and the interaction experience, such that when VP adaptivity increased, asynchrony and perceived synchrony decreased. High levels of BPD traits were associated with higher asynchrony and variability, depending on the level of VP adaptivity, and an overall more negative perception of synchrony and affect. These findings show that high BPD traits are associated with reduced interpersonal synchrony during interaction. Consistent with these findings, interventions might consider the potential role of interpersonal synchrony in building the therapeutic relationship.