Connected at heart? Socioeconomic status and physiological linkage during marital interactions

When people connect, their heart rates may become synchronized. Research has documented greater interdependence among people from lower socioeconomic status (SES) backgrounds, but little is known about whether greater interdependence also emerges at a physiological level in low-SES contexts. The present laboratory-based study examined physiological linkage (i.e., coordinated changes in interbeat interval on a second-by-second basis) in 48 married couples (96 spouses) from highly diverse SES and racialized backgrounds across two marital interaction contexts (i.e., a conflict and a pleasant conversation). We analyzed both in-phase (i.e., coordinated changes in same direction) and anti-phase (i.e., coordinated changes in opposing directions) linkage. The overall sample size was N = 192 observations (48 couples with four repeated measures: in-phase and anti-phase linkage in conflict and pleasant conversations). Repeated measures analyses showed that, across both conversations, spouses from lower (vs. higher) SES backgrounds showed lower anti-phase and greater in-phase physiological linkage, with the difference in anti-phase linkage being more pronounced. That is, their heart rates were less likely to change in opposite ways and more likely to change in similar ways. These findings provide the first evidence that privileged couples connect differently from less privileged couples at a physiological level, contributing to conversations on how macro-level factors become embedded and embodied in the micro.