Night-Owl People Bigger Risk Takers Than Early Risers

By Jane Farrell

Women who are night owls are as likely as men to be risk-takers. They’re also liable to be single or have short-term romantic relationships.

Research by a professor from the University of Chicago suggests that night owls are different from early risers in very important ways.

The research suggests that sleep patterns are linked with important character traits and behavior.

“Night owls, both males and females, are more likely to be single or in short-term romantic relationships versus long-term relationships, when compared to early birds,” said study author Dario Maestripieri, professor in Comparative Human Development.. “In addition, male night owls reported twice as many sexual partners than male early birds.”

The study, published in the journal Evolutionary Psychology, analyzed statistics from earlier research of more than 500 graduate students at the University of Chicago Booth School of Business. That initial study found men are more willing to take financial risks than women.

Maestripieri wanted to explore why men take more risks than women. He was curious whether sleep patterns have any influence on these tendencies, through an association with differences in personality and in novelty-seeking.

The men in the study had higher cortisol and testosterone levels than women; however, night-owl women had cortisol levels comparable to night-owl and early-morning men. Maestripieri’s study suggests high cortisol levels may be one of the biological mechanisms explaining higher risk-taking in night owls.

Some people have chronically high levels of cortisol, which is known to increase during periods of stress. Higher cortisol can be associated with higher cognitive function, he said, and some studies show that high-achieving, successful people have high cortisol levels.

More men than women consider themselves night owls, the study found, and men sleep less overall. Maestripieri said preferences for being a night owl or early morning person are due in part to biology and genetics, but also can be influenced by environmental factors such as shift work or child-rearing. Gender differences in sleep patterns emerge after puberty and become weaker or disappear after women reach menopause, Maestripieri said.

The link between the night-owl tendency and risky behavior could have roots in evolutionary strategies for finding mates, Maestripieri said.

Maestripieri said he has replicated the main result of higher risk-taking in night owls with a non-student population and hopes to publish those findings soon.