A recent study of heterosexual couples found that those who slept in physically closer positions at the onset of sleep reported lower stress and less insecure emotional attachment. However, the individual sleep positions people preferred—such as sleeping on their back, side, or stomach—were not associated with the positions they took when sleeping with their partner. The study was published in the Journal of Social and Personal Relationships.
Sleep is essential for physical and mental health. It supports cognitive functioning, mood regulation, immune system strength, and overall well-being. While sleep is often studied as an individual activity, most adults share their bed with a romantic partner.
Sleeping with a partner can promote feelings of safety and emotional connection, which may enhance sleep quality. Physical closeness during sleep—such as cuddling or spooning—can increase the release of oxytocin, a hormone associated with bonding and relaxation. Research suggests that couples who synchronize their sleep patterns tend to report higher relationship satisfaction and better sleep quality.
Study authors Josh R. Novak and Kaleigh C. Miller noted that while couples often maintain their “own side” of the bed, they regularly cross this boundary for cuddling, affection, and sex. They also pointed out that people may adopt different sleep positions when sharing a bed compared to when sleeping alone.
The researchers conducted a study to examine whether individuals’ preferred sleep positions were related to the sleep positions they used with their partners at sleep onset (when they first go to sleep, before shifting during the night). They also explored whether physical closeness during sleep was related to sleep disorders, perceived stress, attachment styles, and other relationship characteristics.
The study surveyed 143 heterosexual couples, comprising 286 individuals. The average age was 43 for men and 40 for women, and couples had been together for an average of 13 years. Fifty-two couples reported having the same chronotype (morning or evening preference).
Participants reported the degree of physical closeness in their typical sleep position at sleep onset. They also completed assessments of perceived stress, attachment insecurity (using the Experiences in Close Relationships Scale–Short Form), sleep disturbance (via the PROMIS Sleep Disturbance scale), daytime sleepiness, and their preferred individual sleeping position. Additional demographic and contextual information was collected, including relationship length, income, and whether children or pets shared the bed.
The results showed no significant association between an individual’s preferred sleeping position and the couple’s sleep position at onset. However, couples who reported physically closer sleep positions—such as spooning, sleeping intertwined, or face-to-face—also reported lower levels of perceived stress and lower levels of anxious or avoidant attachment.
“We found that closer couple sleep positions (spooning, intertwined, or face-to-face) were linked with lower couple perceived stress and less insecure attachment, but were not linked with sleep disturbance either directly or indirectly. Thus, our study lends support to the idea that cuddling at sleep onset may be beneficial for physiological and relational functioning, but future research in this area is critically needed, and much remains to be explored and understood,” the study authors concluded.
The study sheds light on the links between couple sleep positions and the quality of their relationships. However, the cross-sectional nature of the study limits causal interpretation. It remains unclear whether physical closeness improves relationship quality or if more secure couples naturally sleep closer together. Additionally, the researchers note that sleep positions at onset may not reflect how couples sleep throughout the night.
The paper “‘Cuddle buddies’: Couples sleep position closeness at onset is indirectly related to lower insecure attachment through lower couple perceived stress” was authored by Josh R. Novak and Kaleigh C. Miller.
