Why thinking you had a good night’s sleep is more important than actually getting one

Simply thinking you had a good night’s sleep is more significant to your mood than actually getting a good night’s sleep, a new study suggests.

The study, published in the journal Emotion, found that just feeling like you had a restful sleep has a greater impact on well-being than paying attention to target sleep goals and what sleep trackers have to say about sleep quality.

Researchers at the University of Warwick wanted to determine how changes to people’s usual sleep patterns and sleep quality are correlated to mood and satisfaction with life the following day.

“Our findings are consistent with our previous research that identified people’s self-reported health, and not their actual health conditions, as the main factor associated with their subjective well-being and especially with life satisfaction,” Professor Anu Realo, from the Department of Psychology at the University of Warwick, said in a press release.

“It’s people’s perception of their sleep quality and not the actigraphy-based sleep efficiency which matters to their well-being.”

Researchers asked over 100 people aged 18-22 to keep a sleep diary about the previous night’s sleep over a period of two weeks.

The sleep diaries included information about the time they went to bed, started to get ready to fall asleep, how long it took them to fall asleep, their wake-up time, when they got out of bed and how satisfied they generally felt about their sleep.

Participants also wore actigraphs on their wrists in order to measure their movement and estimate sleep patterns and cycles.

“Even though a sleep tracking device might say that you slept poorly last night, your own perception of your sleep quality may be quite positive. And if you think that you slept well, it may help better your mood the next day,” lead author Dr. Anita Lenneis, from the University of Warwick’s Department of Psychology, said.

“On the contrary, if a sleep tracker tells you that you slept well, but you did not experience the night as such, this information may help you to reassess how well you actually slept. A sleep tracker offers information about your sleep which is typically not accessible whilst being asleep. So, it may improve your subjective perception of last night’s sleep and thereby your overall next day’s well-being.”

Those who participated were then asked to record and rate both their positive and negative emotions, as well as how content they were with their lives, five times throughout the following day.

The actigraphy data was compared to the subjects’ self-reported impression of their sleep and how they felt the next day.

“Our results found that how young people evaluated their own sleep was consistently linked with how they felt about their well-being and life satisfaction,” Lenneis said.

Lenneis continued, “For example, when participants reported that they slept better than they normally did, they experienced more positive emotions and had a higher sense of life satisfaction the following day. However, the actigraphy-derived measure of sleep quality which is called sleep efficiency was not associated with next day’s well-being at all.”

“This suggests there is a difference between actigraphy-measured sleep efficiency and people’s own perception of their sleep quality in how they link to people’s evaluations of their well-being.”