Parent–child relationship quality buffers the association between mothers' adverse childhood experiences and physiological synchrony

Family environment plays a critical role in shaping stress response systems. Concordance between mothers' and children's physiological states, specifically their Respiratory Sinus Arrhythmia (RSA), reflects dyadic co-regulation. Negative or weakened RSA synchrony during interactions is linked to various psychosocial risks, but existing research has focused on risks in the mother or child as opposed to the dyad. This study examined the association between maternal-child RSA synchrony and maternal ACEs, given documented associations with offspring RSA, as well as more proximal documented risks, including maternal psychopathology and children's early adversity and psychopathology. Given that sensitive parent-child relationships are a powerful source of resilience, we tested whether parent-child relationship quality buffered associations between maternal ACEs and RSA synchrony.