5 days ago
Among youths, are night owls more impulsive than morning larks?
Among adolescents, night owls appear to be more impulsive than their morning lark peers, according to a new study being presented at the SLEEP 2025 annual conference in Seattle.
Those with a self-reported preference for staying up late and sleeping in — the night owls — reported 'greater negative urgency and lack of perseverance, which are two aspects of impulsivity,' according to material from the American Academy of Sleep Medicine. The release said they were more apt to act impulsively when they experienced negative emotions and they quit tasks that felt difficult.
But when objective measurements of circadian phase were used, the research didn't find an association between sleep-time preference and impulsivity.
'Surprisingly, we did not find a significant link between dim light melatonin onset and impulsivity in our sample,' said lead author Riya Mirchandaney, a doctoral candidate in clinical-health psychology at the University of Pittsburgh. 'This suggests that there may be unmeasured psychological or behavioral factors influencing both impulsivity and the self-assessment of circadian preference, regardless of the timing of an individual's internal circadian clock.'
The academy describes circadian rhythms as biological rhythms that all living organisms have. It's a body clock synchronized to a 24-hour light-dark cycle. 'Circadian preference reflects an individual's desired timing of sleep and wake, and circadian timing can be objectively measured by analyzing saliva or blood plasma to detect dim light melatonin onset,' the group notes.
More than 200 adolescents took part in the research across two different studies. They were average age of 17 and just over 6 in 10 were female. The study relied on self-reported assessments of impulsivity and circadian preference, then lab samples of saliva were used to assess biological circadian phase by looking at dim light melatonin onset. For a week, the participants also wore a wrist device to estimate their sleep midpoint and sleep duration. Each also completed an assessment of impulsivity at bedtime.
Mirchandaney said the results might one day be used to study how to help teens temper impulsivity, 'a well-established contributor to alcohol and substance use,' per the release.
The researchers believe that adolescence could be a valuable developmental period for using therapeutic interventions to advance sleep and circadian timing.
The National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism both contributed to funding the study. Its abstract was published in an online supplement of the journal Sleep.
Other studies back up the link between adolescent sleep and impulsive behaviors. For example, in 2019, a study from Sweden published in Sleep Medicine: X reported a 'bidirectional' link between adolescent sleep problems and impulsive behaviors over time.
'Youths who experienced sleep problems also experienced increased difficulties with impulse control, and problems regulating impulses were also linked with increases in sleep problems, and these effects were systematic over two years. Moreover, age did not moderate these associations but impulsive behaviors had a larger impact on girls' insomnia as compared to boys,' per that study.
Johns Hopkins University has reported that 'teens love to label themselves 'night owls,' trading stories of all-nighters and sleeping away an entire Saturday.' The article notes that adolescent and teen years are a time when a natural shift in circadian rhythm occurs, so they are frequently wide awake at 11 p.m. and then sleep-deprived because of school start times and homework and other activities.
Pediatrician Dr. Michael Crocetti reported that teens need between nine and nine-and-a-half hours of sleep, which is an hour more than they needed when they were 10.
The extra hour — if they actually get it — helps with growth, brain development and also protects from some serious consequences like depression and poor choices like drug use.
That article ties in some suggestions to encourage more sleep among teens, including starting the day with a burst of sunshine, linking car privileges to good sleep, encouraging afternoon naps and banning texting from the bedroom, among other things.
The experts at Johns Hopkins also suggest avoiding a drastic summer shift of pushing the sleep schedule too far off track because school's out. That could make it very hard to get back on track when school resumes. But it could also create other issues, like moodiness or excessive sleepiness during the day.
There are other reasons to ponder youthful sleep patterns, including the fact that bad habits formed early may stick or create long-lasting challenges.
And it's not just among adolescents, either. As Deseret News reported in 2022, night owls may be more apt to develop heart disease or diabetes than are the morning larks. And those who rise early 'seem to burn more fat as an energy source and are often more active than those who stay up late.'
Those are findings from Rutgers University, published in the journal Experimental Physiology. The study said the two groups were similar in body composition, but the early risers were more sensitive to insulin levels in their blood and burned fat better while exercising and resting. Night owls didn't burn as much fat for energy; they used carbohydrates.
