Sleep Tight, Don’t Fight? Daily Sleep Quality and Marital Strain in Same- and Different-Sex Marriages in the United States

Sleep is a critical health behavior that often varies by gender, and most partnered adults sleep with a significant other. Despite growing research on sleep health, little is known about how daily sleep within couples shapes marital dynamics, especially across same- and different-sex relationships. This study uses dyadic diary data from 378 mid- to later-life couples in the United States (N = 756) to examine how respondents’ and partners’ daily sleep quality are each associated with daily marital strain and whether these associations vary by gender and couple type. Respondent sleep quality predicts lower marital strain for all couple types except for men married to women. Spousal sleep quality is also associated with reduced strain but only for women in different-sex marriages. These women appear uniquely affected by both their own and their partner’s sleep, highlighting the importance of dyadic and gender-relational perspectives in understanding links between sleep and relationship dynamics.