||Although couples research tends to focus on interactions of high salience interactions, it is likely that couples spend the majority of their time engaged in interactions of low salience (i.e., completing chores, having everyday conversations, being in the same physical space). Theory suggests that physiological functioning should be more efficient when in the presence of a spouse during both low- and high-salience interactions. It is likely that this increased efficiency in physiological functioning may be observed in a decrease in high-frequency heart rate variability (HF-HRV). The purpose of this study was to determine how much time couples spend engaged in both low- and high-salience interactions, whether physiological functioning is more efficient in the presence of a spouse during a low-salience interaction than alone, and whether relationship satisfaction moderates this change in functioning. Participants completed two consecutive 5-minute resting baselines, one in the presence of their spouse and one alone. Consistent with predictions, participants reported spending significantly more time engaged in low-salience interactions than high-salience interactions. Further, results indicated a significant increase in HF-HRV for participants who completed their first baseline alone and had their spouse reintroduced for the second baseline. No significant effects were found for heart rate or moderation by relationship satisfaction. Taken together, results suggest that participants are experiencing physiological stress during baseline. Additionally, anticipation of conflict in the study may turn one's spouse into a stressor during baseline. Limitations and future directions are discussed.