Exploring cardiac physiological synchrony and its implications for stress and anxiety

When two individuals share a common experience, their heartbeats can become synchronized in a phenomenon known as cardiac physiological synchrony (CPS). This interpersonal coupling of heart rate and heart rate variability is considered a component of social behavior and may facilitate close emotional, physical, and prosocial interactions. However, the exact mechanisms underlying CPS are unknown, including its potential differential roles in various types of empathy. Notably, CPS is distinct from the direct electrical coupling that occurs between cardiomyocytes. We therefore review the current literature on CPS and the hypothesized mechanisms driving heartbeat synchronization. The consequences of either reduced or increased CPS during social interaction are not well studied. Existing evidence suggests that CPS may tune social interaction, potentially promoting prosociality or alleviating stress and anxiety depending on context. We hypothesize that variations in CPS may correspond to different types of empathy and could be linked to specific types of anxiety. Finally, we discuss the implications of CPS for mental health, therapeutic interventions, and strategies aimed at reducing chronic stress and anxiety. A deeper understanding of CPS mechanisms and consequences could help to noninvasively improve mental and physical well-being and mitigate structural degeneration in brain regions essential for memory and cognition.