News · Sleep
Staying up to socialize cost students 1.4 hours of sleep
Researchers wired a residential college with Bluetooth beacons and sleep watches for two weeks and found students who delayed bedtime to socialize slept 1.4 hours less and felt worse the next day.
Based on a peer-reviewed study in SLEEP
- Researchers at Duke-NUS Medical School in Singapore studied 104 students living in the same residential college over one two-week period, publishing in the journal SLEEP.
- Sleep came from actigraphy watches; who was physically near whom came from Bluetooth beacons, so socializing was measured rather than just reported.
- On nights students delayed bedtime for social reasons, they slept 1.4 hours less and reported worse mood and more daytime sleepiness the next day.
- Students' bedtimes were strongly correlated with their last measured proximity to the person who delayed their bedtime, pinning the delay to a specific companion.
- Higher scores for extraversion and need to belong predicted being part of, and having stronger ties within, the late-night social network.
- This is 104 students in one residential college over two weeks. It is observational, and the paper is paywalled beyond its abstract.
Everyone knows the feeling of the conversation that will not end. It is midnight, you have an early start, and leaving feels rude. Researchers in Singapore worked out what that costs, and it is more than most people would guess.
A study in the journal SLEEP fitted 104 students in a residential college with sleep-tracking watches and Bluetooth beacons that logged who was standing near whom. On nights when students delayed bedtime for social leisure activities, they slept 1.4 hours less and felt measurably worse the following day.
Measuring an excuse
Bedtime procrastination has previously been studied through questionnaires, which means researchers heard the story people tell about their evenings. This study instead measured sleep patterns and physical proximity in 104 students during the same 2-week period.
Everyone was in the same building at the same time, so the beacons could reconstruct who was with whom when the delay happened. That is what makes the design unusual: it turns a social excuse into a data point.
The finding, and the culprit
In-person social bedtime procrastination was associated with shorter sleep by 1.4 h and worse next-day mood and daytime sleepiness compared with not delaying bedtime.
Then comes the detail that gives the study its bite. Students’ bedtimes were strongly correlated with their last objectively measured proximity to the person who delayed their bedtime. The watch says when you fell asleep; the beacon says who you were standing next to beforehand. Bedtime, in other words, was being set by whoever was in the room.
Who stays up
The researchers also asked why some students were repeatedly caught in this and others were not, and the answer was personality rather than discipline. Students who scored higher on extraversion and need to belong were more likely to be part of, and had stronger ties within, the social bedtime procrastination network.
That reframes the behavior. Losing sleep to company is not simply a failure of willpower; for some people it is the predictable result of valuing company. The authors put it as students accepting the tradeoff to satisfy their drive to socialize or need for belonging.
What it does not cover
The setting is doing a lot of work here. A residential college puts friends within a few steps of each other at midnight, with no commute waiting and a timetable that often forgives a late start. Few adults live like that, and the 1.4-hour figure should not be lifted out of that context.
The study is also observational, with 104 participants over two weeks, and it sits behind a paywall, so the authors’ full account of their own limitations is not available here. Nights when someone stayed up socially may have differed in other ways, including alcohol, deadlines or the day that preceded them.
What holds up is the pairing of two measurements that rarely appear together: objective sleep and objective proximity, in the same people on the same nights.
The authors’ conclusion is blunt for a sleep paper. Socially motivated bedtime procrastination is a major barrier to obtaining healthy sleep in residential college students.
The conversation may well be worth having. The evidence just says you will pay for it before lunch.
People also ask
What is bedtime procrastination?
It is going to bed later than you intended without any external reason forcing you to. The classic version is scrolling a phone alone. This study looked at a social variant: staying up because other people are still up, which the researchers call in-person social bedtime procrastination. It is the difference between losing an hour to your phone and losing it to a conversation in someone's room.
How much sleep did it actually cost?
On nights involving in-person social bedtime procrastination, students slept 1.4 hours less than on nights they did not delay bedtime. Over a week that is close to a full night of sleep, which is why the researchers describe it as a major barrier to obtaining healthy sleep in this group.
Was it worth it? Did socializing improve their mood?
Not the next day. Students reported worse next-day mood and more daytime sleepiness after socially delayed bedtimes, so the researchers conclude that individuals who forgo sleep to socialize are worse off the next day. The study did not measure whether the socializing itself felt rewarding in the moment, which is presumably why people keep doing it.
Why do some students do this more than others?
Personality predicted it. Students who scored higher on extraversion and need to belong were more likely to be part of the late-night social network, and had stronger ties within it. The researchers suggest those students may accept the tradeoff to satisfy a drive to socialize or a need for belonging, rather than through poor self-control.
Does this apply to adults who are not students?
Directly, no. This was 104 people in a residential college, an unusual environment where friends are meters away at midnight and there is no commute the next morning. The underlying tension between sleep and social life is familiar well beyond campus, but the size of the effect measured here should not be assumed to transfer.