At the heart of couple conflict: Emotion regulation and cardiac reactivity.

Adaptive emotion regulation can buffer against cardiac reactivity under acute stress. However, research on the effectiveness of emotion regulation in the face of interpersonal stress is scarce. We therefore conducted an experiment investigating whether emotion regulation might buffer against parasympathetically mediated cardiac reactivity during conflict. Couples engaged in a 10-min conflict discussion (N = 253 participants included in the final analyses). Prior to the discussion, one partner per couple was randomly assigned to one of three experimental conditions (acceptance, cognitive reappraisal, control group). In both emotion regulation groups, the manipulated partner was instructed to apply either acceptance or cognitive reappraisal during the following conflict. Vagal (i.e., parasympathetic) activity as indexed by the heart rate variability (HRV) parameter RMSSD was assessed at baseline and during conflict. Cardiac reactivity was operationalized as the difference between baseline vagal activity and vagal activity during conflict. Both emotion regulation strategies significantly reduced cardiac reactivity in the manipulated partner as compared to the control group. We thus found preliminary support that emotion regulation may beneficially alter parasympathetically mediated cardiac reactivity during acute interpersonal stress.