Teens who stay up late at night cramming are more likely to have academic problems the following day — doing poorly on the test they studied for — finds a new study by University of California, Los Angeles (UCLA), researchers.
Since students increasingly give up sleep for studying as they get older, the researchers say the problem compounds over time. The study involved 535 students from Los Angeles high schools. For 14 days during each of three school years — 9th, 10th and 12th grades — the participants kept diaries tracking the amount of time they spent studying, how much they slept at night and whether or not they experienced academic problems the next day, such as not understanding something taught in class or doing poorly on a test, quiz or homework.
The data showed that kids who didn’t get enough sleep were not only more likely to have problems understanding during class, a result the researchers had expected, but they were also more likely to do badly on tests, quizzes and homework — the very outcome the students were staying up late to avoid. “If you’re really sacrificing your sleep for that cramming, it’s not going to be as effective as you think, and it may actually be counterproductive,” says study author Andrew J. Fuligni, professor of psychiatry and biobehavioral sciences at UCLA.
Overall, students spent an average of just over an hour studying each school night throughout their high school years, but their average sleep time decreased by an average of 41.4 minutes from 9th to 12th grade. When they got enough sleep, 9th and 10th graders reported an average of one academic problem every three days; by 12th grade the rate of academic problems they experienced was reduced to one problem every five days. However, when teens spent more time studying and less time sleeping than usual, the following days were characterized by more academic problems than normal.
“This wasn’t a whopping effect, it wasn’t a huge effect, but it was a consistent pattern that when kids crammed, they had problems the next day,” says Fuligni. “That surprised us until we saw that when they crammed, they got significantly less sleep and when that happens, it’s more difficult to learn what you’re studying.”
The National Sleep Foundation says that teens function best with 8.5 to 9.25 hours a sleep a night, but Fuligni says that in his research, teens are rarely getting that much.”This is fairly standard when people do teenage sleep surveys. [Teens] usually get less [sleep] than experts recommend and that’s not unique to this study. Sleep goes down during the high school years,” says Fuligni.
The authors stress that they’re not encouraging teens to spend less time studying. As experience and research confirm, kids who study more tend to earn higher grades. Rather, the solution lies in better time management overall. “[Students] should balance their studying across the week and anticipate what is going on. Try to have a regular study schedule so that you’re not going to have those nights spent cramning,” says Fuligni.
The new study was published in the journal Child Development.