Closer friends have more similar actigraphy-estimated sleep patterns

Area of Science:

• Behavioral Science
• Sleep Medicine
• Social Psychology

Background:

• Health behaviors, including sleep, often align among individuals in close relationships.
• Understanding social influences on sleep is crucial for public health.
• University students represent a population with unique social dynamics and sleep challenges.

Purpose of the Study:

• To investigate the association between friendship closeness and objectively measured sleep patterns in university students.
• To determine if sleep timing and duration are more similar in close friendships compared to casual friendships.
• To examine the daily covariation of sleep patterns within friend pairs.

Main Methods:

• Utilized actigraphy watches and daily sleep diaries to collect sleep data from 150 friend pairs over two weeks.
• Classified friendships as close or casual based on mutual friend rankings.
• Employed linear mixed models to analyze differences in sleep timing and duration between friends, considering friendship closeness and covariates.

Main Results:

• Friend pairs in close friendships showed significantly smaller differences in sleep timing (approx. 30 minutes) on non-school nights compared to casual friends.
• On school nights, sleep timing differences were linked to chronotype and class schedules, not friendship closeness.
• Sleep timing and duration demonstrated positive covariation in close friendships, suggesting mutual influence, regardless of next-day classes.

Conclusions:

• Objective sleep patterns are more synchronized in close university friendships.
• Daily sleep covariation in close friendships highlights the impact of social interaction on individual sleep behaviors.
• Friendship closeness, chronotype, and academic schedules are key factors influencing social sleep dynamics.