The key to a long, restful night’s sleep may depend on your worldview. Optimists sleep longer and better, according to new research from the University of Illinois.

Rosalba Hernandez, a professor of social work at the University of Illinois, said in a releasethat the long-term study results “revealed a significant association between optimism and various characteristics of self-reported sleep after adjusting for a wide array of variables.”

Researchers studied a sample of 3,500 people aged 32-51. Their optimism levels were measured from between 6 and 30 using a survey which asked them to rate how much they agreed with statements like “I’m always optimistic about my future,” and “I hardly expect things to go my way.”

The participants reported on their sleep twice, five years apart. They rated the quality of their sleep and its duration from the past month. They also reported on sleep problems.

All said, the researchers found that with each standard deviation increase in participants’ optimism score, they had 78% higher odds of reporting “very good” sleep quality.

Similarly, people who scored higher for optimism were more likely to sleep six to nine hours a night – and be 74% more likely not to suffer from insomnia or be sleepy during the day.

In short, the more optimistic you are, the more likely you are to sleep better – and longer.

It also pays, health-wise, to be an optimist in general, said Hernandez, who led the study. “Dispositional optimism – the belief that positive things will occur in the future – has emerged as a psychological asset of particular salience for disease-free survival and superior health.”

While researchers aren’t sure exactly what bodily process causes optimists to sleep longer and better sleep, Hernandez hypothesizes that optimists see their problems more positively and cope with them well. Therefore, when it’s time for bed, they don’t lay awake, worrying and ruminating.

The news is enough to make you look on the bright side no matter what your disposition.

This article was originally published on The Ladders.

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