Night Owls Might Have One Very Real Advantage Over Early Birds — But There’s a Catch
If you’re someone who routinely hits the snooze button to get a few more precious moments of sleep-mask time before your morning meetings, but find yourself wide awake and scrolling through TikTok at night, your cognitive function might be “superior” compared to those of early birds, at least according to a new study.
The latest findings, which were published in the journal BMJ Public Health, suggest that there could be a difference between night owls and morning people — besides how you might function before a cup of coffee, of course — while also emphasizing that one adage about sleep is still true: getting between 7 to 9 hours of sleep a night is optimal for peak brain health and performance.
Researchers and academics at Imperial College London studied data from 26,000 people who’d taken tests for intelligence, reasoning abilities, memory, and reaction times as part of a UK Biobank study. They then compared this information to the participants’ sleep quality and duration, as well as what times the participants said they felt most focused and productive, to see how it affected their cognitive abilities.
Night owls scored better on these tests, suggesting a link between a later bedtime and enhanced brain performance. In other words: if you’re a night owl, you may finally have something over those self-righteous early birds.
While there’s no shortage of sleep studies that explore the relationship between adequate, healthy sleep to cognitive function and overall brain health, this study attempts to fill in more information on the effect of chronotypes — basically when each individual feels their most alert and focused, as well as their desired time of the day to sleep and wake up — on cognition.
The study participants were divided into two groups, and scored how well they performed on digital tests for reasoning, matching, reaction time, and prospective memory. While those who stayed up late or had “intermediate” bedtimes tended to score higher, there are a few caveats from the study before you lean into a later bedtime.
For example, though researchers used men and women of varying sex, birth year, BMI and other health measures, they didn’t adjust for levels of educational attainment due to incomplete data in that area, and they didn’t include the time the cognitive tests were conducted.
In addition, the group surveyed was aged 40-70, meaning younger participants’ answers weren’t included. Participants also self-reported how many hours they slept in a 24-hour period, as well as their identification into three groups: “Morningness” (basically someone who is “definitely a morning person”), “Intermediate” (more of a morning than an evening person, or vice versa), and Eveningness (someone who is “definitely an evening person”). The findings were that both Intermediate and Evening people scored higher on these tests, but the Intermediate category included both morning and evening participants.
Jacqui Hanley, the head of research funding at Alzheimer’s Research UK, said that it’s good to take these findings with a grain of salt. “Without a detailed picture of what is going on in the brain, we don’t know if being a ‘morning’ or ‘evening’ person affects memory and thinking, or if a decline in cognition is causing changes to sleeping patterns,” Hanley said, per The Guardian.
However, the key takeaway is that getting just enough sleep is paramount to your cognitive health. The study’s author Raha West, MBChB, MRCA, told Medical News Today that participants who were outside the recommended 7 to 9 hours of sleep did poorly on the tests, no matter their chronotype.
“Our finding of the association between sleep duration and cognitive function, with 7 to 9 hours of sleep being optimal, is significant because it aligns with existing evidence and highlights the importance of optimum sleep for maintaining cognitive health,” West said. “This finding showed that not only too little but also too much sleep may be detrimental to brain performance.”