There are many reasons why college and university students often fail to get full nights of sleep.

Many American students are away from their parents for the first time when they attend college. They might not be used to having total freedom in how they plan their days and nights.

Parties, late night study meetings, or just time spent relaxing with friends – these are all things that cut into college students' sleep habits.

A few years ago, Michael Scullin began teaching the science of sleep to psychology students at Baylor University in Waco, Texas. Scullin is an assistant professor at Baylor and the director of its Sleep Neuroscience and Cognition Laboratory.

The class centered round the why the body needs to sleep and the physical and mental health problems caused by a lack of sleep. This includes difficulty focusing on studies or controlling one's emotions, and increased risk of many diseases.

"When you are at your most sleep-deprived is when you are least likely to be able to judge how sleepy you are, and how much that sleepiness is impacting you," Scullin told VOA.

He says his students seemed to enjoy the class and were interested in the material he was teaching. But when he asked them whether they were choosing to get more sleep after what they had learned, most of them said no.

The United States Centers for Disease Control and Prevention states that adults need at least seven hours of sleep a night to stay healthy. So Scullin came up with a plan to get his students to sleep more: he offered to give them extra points on their final exam, the class's most important test.

The plan worked better than Scullin expected. Students who slept more performed better in two different classes, and Scullin published his findings in two academic publications last November.

A student sleeps in the hallway of Hall Memorial Building on the campus of Gallaudet University on Friday, October 6, 2006, in Washington, DC.

How did the study work?

Scullin started the experiment with his psychology students. He told them that if they agreed to sleep at least eight hours a night for the last five nights before the final exam, they would get several extra credit points. But if they agreed to take part in the study and failed to get the required amount of sleep, they would lose points on the exam. The students would wear special devices that recorded their sleep data.

Only eight out of the 18 total students in that first group agreed to take part in the experiment. Yet all the students who took part performed better on the exam than those who did not, even before the extra credit points were added. On average they earned about 5 points more on the exam.

Scullin then decided to repeat the study with another group of 16 design students. He chose not to punish students who failed to sleep the full eight hours per night, and got the same results.

Daniel Bessesen is a medical doctor who researches sleep, and was not involved in the study. He is also the Associate Director of the Anschutz Health and Wellness Center at the University of Colorado outside Denver. Bessesen notes this study does lend support to the idea that sleeping enough helps academic performance, and students who cram are likely worse off.

"Cramming" is a common activity for American college students. When students cram, they study most or all of the night before the exam. They get very little or no sleep because they think they will do better if the test material is fresh in their minds.

Bessesen says there are some problems with Scullin's experiment. He says to be more scientific, the students should have been randomly chosen for sleeping or staying awake. Also, the two groups should have been studying the same subject and taking the same test. All of this may have affected the results of the study.

How to get people to sleep more

Yet Bessesen says this experiment does fit in with a larger body of research on the importance of sleep. In fact, the amount of sleep people get has been decreasing greatly, he says. A 2015 study found the number of Americans who sleep less than six hours a night increased by about 30 million between 1985 and 2012.

Scullin and Bessesen offer some ways to avoid health problems caused by a lack of sleep. Among these, they say, parents should try to get enough sleep themselves to demonstrate its importance to their children. Bessesen notes that even some medical school programs have begun to require student doctors to sleep more to prevent accidents.

Scullin also offers a few pieces of advice to his students who have difficulty falling asleep. They include the following:

Avoid looking at electronics before you are about to fall asleep. Do not drink anything with caffeine in it, such as coffee or tea, less than six hours before you go to sleep. Try to go to sleep at the same time every night. If you are lying in bed trying to sleep and cannot calm your mind, get out of bed. Take out a piece of paper and spend five to ten minutes writing down all of your thoughts. If you wake up in the middle of the night and cannot fall back asleep, get out of bed and go into another room. Do not turn on the lights! Instead, wait there until you start to feel tired again.

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