Spatial proximity as a behavioral marker of relationship dynamics in older adult couples

Background: Close relationships in older adulthood are characterized by heightened interdependence, which has implications for health and well-being as partners age together. Purpose: We describe a novel method that uses partners’ spatial proximity to examine the dynamics of interpersonal relationships. Research Design: In a sample of 10 older adult couples over a 14-day study period, we linked a continuous measure of partners’ spatial proximity with partners’ heart rates—a physiological marker of arousal. Results: Cross-correlations showed that proximity was consistently associated with each partner’s heart rate, but the magnitude and sequence of the correlation varied from day-to-day, suggesting that the coupling of proximity and heart rate is a dynamic of the interaction, rather than the couple. Additionally, our predictive model showed that all three time-series were necessary for optimal prediction, demonstrating that proximity and partners’ heart rates are dynamically intertwined. Conclusion: Together, these results demonstrate meaningful and predictable variation in couple dynamics at the momentary level that consists of a complex association between physiological and spatial proximity.