Night owls, unlike early birds, tend to be unmarried risk-takers

April 1, 2014 by Jann Ingmire
Nighthawks, by Edward Hopper (1942). Credit: The Art Institute of Chicago

(Medical Xpress)—Women who are night owls share the same high propensity for risk-taking as men, according to a recent study by a University of Chicago professor.

The research suggests that are linked with important character traits and behavior, said study author Dario Maestripieri, professor in Comparative Human Development. Night owls—people who tend to stay up late and wake up late in the morning—are different in many important ways from early risers, he found.

"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," Maestripieri said. "In addition, male night owls reported twice as many sexual partners than male early birds."

The study, published in the February edition of the journal Evolutionary Psychology, draws on data from earlier research of more than 500 graduate students at the UChicago Booth School of Business. That initial study assessed financial risk aversion among male and female students and found men are more willing to take financial risks than women. Females with high testosterone levels, however, were more similar to males in financial risk-taking, that study found.

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 study participants (110 males and 91 females) provided saliva samples to assess their levels of cortisol and testosterone. Those levels were measured before and after participants took a computerized test of their tendencies for financial risk aversion. The participants also described their own willingness to take risks and gave information about their sleep patterns.

Men 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 may be one of the biological mechanisms explaining higher risk-taking in night owls.

Maestripieri explains that some people have chronically levels regardless of stress, which is known to increase cortisol for short periods of time. These people have high metabolism, high energy and arousability. Higher cortisol can be associated with higher cognitive function, he said, and some studies show that high-achieving, successful people have high .

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 genetic inheritance, 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.

"From an evolutionary perspective, it has been suggested that the night-owl trait may have evolved to facilitate short-term mating, that is, sexual interactions that occur outside of committed, monogamous relationships," Maestripieri said. "It is possible that, earlier in our evolutionary history, being active in the evening hours increased the opportunities to engage in social and mating activities, when adults were less burdened by work or child-rearing." The findings that night owls are less likely to be in long-term relationships and that male night owls report a higher number of sexual partners offer some support to this hypothesis, he said.

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

Explore further: Study finds night owls more likely to be psychopaths

More information: "Night owl women are similar to men in their relationship orientation, risk-taking propensities, and cortisol levels: Implications for the adaptive significance and evolution of eveningness." Dario Maestripieri Evolutionary Psychology 12(1): 130-147. www.epjournal.net/wp-content/u … ads/EP1201130147.pdf

Related Stories

Study finds night owls more likely to be psychopaths

August 1, 2013
(Medical Xpress)—People who stay up late at night are more likely to display anti-social personality traits such as narcissism, Machiavellianism, and psychopathic tendencies, according to a study published by a University ...

Stress hormone levels associated with grip strength and walking speed

February 20, 2014
Lower morning and higher evening cortisol levels contribute to frailty in older individuals, according to new research accepted for publication in the Endocrine Society's Journal of Clinical Endocrinology & Metabolism (JCEM).

Night shifts may be linked to increased ovarian cancer risk

March 14, 2013
Working night shifts might increase the risk of developing ovarian cancer, indicates research published in Occupational and Environmental Medicine.

Stress hormones in traders may trigger 'risk aversion' and contribute to market crises

February 17, 2014
High levels of the stress hormone cortisol may contribute to the risk aversion and 'irrational pessimism' found among bankers and fund managers during financial crises, according to a new study.

Recommended for you

Children with fragile X syndrome have a bias toward threatening emotion

August 23, 2017
Anxiety occurs at high rates in children with fragile X syndrome (FXS), the most common form of inherited intellectual disability. Children with co-occurring anxiety tend to fare worse, but it can be hard to identify in infants. ...

So-called "bright girl effect" does not last into adulthood

August 23, 2017
The notion that young females limit their own progress based on what they believe about their intelligence—called the "bright girl effect"—does not persist into adulthood, according to new research from Case Western Reserve ...

High moral reasoning associated with increased activity in the human brain's reward system

August 22, 2017
Individuals who have a high level of moral reasoning show increased activity in the brain's frontostriatal reward system, both during periods of rest and while performing a sequential risk taking and decision making task ...

Like adults, children show bias in attributing mental states to others

August 22, 2017
Young children are more likely to attribute mental states to characters that belong to the same group as them relative to characters that belong to an outside group, according to findings published in Psychological Science, ...

Yoga and meditation improve mind-body health and stress resilience

August 22, 2017
Many people report positive health effects from practicing yoga and meditation, and experience both mental and physical benefits from these practices. However, we still have much to learn about how exactly these practices ...

Wealth disparity and family income impact the brain development of female youth

August 22, 2017
Female teenagers living in neighbourhoods with wide salary gaps and a low-income household show changes to their brain maturation that could indicate a higher risk of developing mental illness in adulthood, suggests a recently ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.