Night owls are sharper than morning people, study shows

People who are most active and alert in the evenings appear to perform better at cognitive tests

A late night at the office. People who got between seven and nine hours of sleep a night performed best in cognitive tests. Getty Images

Night owls perform better in cognitive tests than morning people, according to a new study.

The research found that people who are more alert in the evening, and others who did not show a preference for night or morning, were sharper, with “superior cognitive function”.

Previous studies have examined the relationship between sleep and cognitive abilities, but much less is known about sleep patterns, chronotypes – the natural inclination of your body to sleep at a certain time – and cognition.

Academics from Imperial College London set out to explore the relationship, examining data on thousands of people held in the UK Biobank study to examine their sleep duration, quality and chronotype – categorised in the study as “morningness”, “eveningness”, or “intermediate” for those who did not align to either of the other two.

People taking part in the study underwent tests that examined their intelligence, reasoning skills, reaction times and memory.

The researchers analysed data on almost 27,000 people, comparing how well they performed in these tests to their self-reported sleep duration, sleep pattern and sleep quality.

People who got between seven and nine hours of sleep each night appeared to perform best in the tests, according to the study, which was published in the journal BMJ Public Health.

Academics also found that night owls and those classed as “intermediate” had “superior cognitive function”.

Being a woman, increasing age and having a diagnosis of angina, high blood pressure and diabetes appeared to “worsen cognitive performance”, they added.

“Our study found that adults who are naturally more active in the evening – what we called 'eveningness' – tended to perform better on cognitive tests than those who are 'morning people',” said the study's lead author, Dr Raha West, from the Department of Surgery and Cancer at Imperial College London.

“Rather than just being personal preferences, these chronotypes could impact our cognitive function.”

She added: “While understanding and working with your natural sleep tendencies is essential, it's equally important to remember to get just enough sleep, not too long or too short. This is crucial for keeping your brain healthy and functioning at its best.”

Study co-leader Prof Daqing Ma, also from Imperial's Department of Surgery and Cancer, added: “We found that sleep duration has a direct effect on brain function, and we believe that proactively managing sleep patterns is really important for boosting, and safeguarding, the way our brains work.

“We'd ideally like to see policy interventions to help sleep patterns improve in the general population.”

Previous studies have linked night owls with a higher risk of health issues.

A study last year found that night owls are more prone to developing diabetes than the wider population.

After accounting for lifestyle factors, an evening chronotype was associated with a 19 per cent increased risk of diabetes.

Among those with the healthiest lifestyles, only 6 per cent had evening chronotypes, compared with 25 per cent of night owls who reported having unhealthy lifestyles.

Evening people were also more likely to drink alcohol in higher quantities, have a low-quality diet, get fewer hours of sleep per night, smoke, and have weight, BMI and physical activity rates in the unhealthy range, the team added.