Researchers highlight the influence of behavior on college students’ circadian preferences

Many people see themselves as night owls or morning larks, and that cannot be changed. It’s called a chronotype — your body’s need for sleep at a given time — and it’s generally considered unchanging. However, a new study from researchers at Baylor University’s Sleep Neuroscience and Cognition Laboratory shows that chronotypes are more flexible than originally thought.

The research team’s findings, “Chronotype in science students is associated with behavioral choices and can fluctuate over a semester,” were recently published in the journal Chronobiology International.

While genetics can drive someone to prefer morning or evening hours, being a night owl can also result from behavioral choices. Whether driven by biology, institutional factors, or behavioral choices, being an evening chronotype can adversely affect sleep health, classroom alertness, and academic success.

Baylor sleep researcher Michael K. Scullin, Ph.D., associate professor of psychology and neuroscience, and Blake Barley, doctoral student of psychology in Scullin’s sleep lab, examined how institutional factors, biological factors, and behavioral choices play a role in sleep problems in college students and whether chronotypes be more malleable than current theories suggest.

Through a series of questionnaires delivered throughout the 2018-2019 academic year, researchers asked 858 undergraduate students enrolled in demanding science courses to rate their sleep behavior and quality, state their chronotype, and rate their academic demands and stress levels. , as well as the amount of sleep. their caffeine consumption and social media use during the day.

Findings

Evening- and morning-type students showed similar stress levels and academic demands, but evening-type chronotypes showed significantly worse sleep quality and duration. Evening types are at a disadvantage if they have to get up early for school or work.

The students who identified as evening types exhibited several behaviors that are known to delay bedtime, shorten sleep duration, and worsen sleep quality. They used social media for 40 minutes while in bed, consumed caffeine later in the day, and took more naps than morning types, resulting in less nighttime sleep, poorer sleep quality, and more sleepiness in class.

As the semester progressed, some students reported a change in chronotype. This chrono switch was linked to changes in behavior, resulting in improved sleep health, less sleepiness, and higher semester GPAs.

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“Engaging in healthier daytime behaviors can lead to better sleep that is then fed back to a better daytime life,” Scullin said. “When your daytime life is better, you can often go to bed earlier and fall asleep earlier, enjoy better sleep quality, and get into a good cycle.”

Students who switched from evening to morning type or who remained morning type showed significantly better semester GPAs than students who remained evening type or switched from morning to evening type. They also reported consuming less caffeine after 5 p.m. and showing significantly better sleep quantity and quality.

Gerst said some simple changes can improve sleep quality.

• Avoid electronics near bedtime.
• Avoid caffeine and other stimulants at least six hours before bed.
• Avoid long naps during the day.
• Avoid exercising in the evenings.

Scullin emphasized that chronotype malleability is a new idea, and that not all night owls should try to become morning larks or vice versa. The focus for each individual should be on getting the quality sleep they need to be healthy and productive.