It is no surprise that teens and young adults are a pretty
sleep-deprived group. Yesterday morning
at 9am, for example, I taught a small class here at the University of
Texas. The students staggered into class
looking like they could use a nap. I
also have three teenagers. They
generally stay up late and get up early during the week, hoping to catch up on
weekends by sleeping all morning.
There are lots of distractions in the modern world that lead
people to stay up late in the night. For
students, though, there is also homework.
On the night before a big exam or a major paper, many students put in a
lot of extra study time in order to prepare.
Does that extra study time help performance in school?
This question was explored in a studying the January, 2013
issue of Child
Development by Cari Gillen-O’Neel, Virginia Huynh, and Andrew
Fuligni. They tracked a group of high
school students in 9th, 10th, and 12th
grade. At each grade level, students
filled out a daily diary for 2 weeks.
Every evening during the study, the students rated the
amount of sleep they got the day before, the amount of time they spent on homework,
and they answered questions about any academic problems they had the previous
day (like doing poorly on a test and having difficulty understanding new
material).
Overall, there was a tendency for high school students to
sleep less as they advanced in school.
So, the 9th-grade-students slept an average of 7.6 hours a
night, while the 12th-graders slept only 6.9 hours per night. Students experienced fewer academic problems
as they advanced in school. That means
that students are actually learning better school skills over the years.
The most important result, though, was that when students
lost sleep because they spent extra time doing schoolwork, they had
significantly more problems the next day than when they got their typical
amount of sleep. This negative effect of
extra study time was strongest for 12th-grade-students and weaker
for the 9th- and 10th-grade students.
What is going on here?
Sleep is important for many reasons. It helps memory. You consolidate memories during sleep. Sleep also helps you focus and sustain
attention. Sleep also gives you energy
to be active. You are much more likely
to be a passive learner when you are tired.
And you learn less when you are passive then when you actively engage
with new material.
So, why are high-school Seniors hardest hit?
The 12th-graders are sleeping least to begin
with. They are just at the edge of their
ability to function properly. When they
disrupt their sleep schedule further with extra study, it has strong
repercussions for the next school day.
The 9th- and 10th-grade students are a bit more
resilient, because they are not as strongly sleep-deprived.
What does this mean?
First off, this study reinforces the general observation
that teens and young adults are not sleeping enough. Getting even an extra 30 minutes of sleep a
night would be a huge benefit for this group.
Second, it means that students need to try to spread their
work out over longer periods of time. It
is an age-old tradition to cram for exams and to finish papers at the last
minute. There are lots of good reasons
to want to avoid cramming. For example,
cramming for an exam may help a student pass that particular exam, but information
learned the night before the test is not remembered in the long-term as well as
information that is studied over several nights. If cramming for a test also reduces the
amount of sleep a student is getting, then that just adds to the problem.
