Smartphone usage may be implicit in trend of lack of sleep in teens

By Mohamad Hamze

For teenagers, increasing smartphone use may mean less sleep – historically low amounts of it, in fact. Results from two national surveys conducted in 2015 found that two in five (40%) high-school students are getting less than seven hours of sleep on average per night, compared with 34% in 2009 and around 25% in 1991. Professor Jean Twenge and her team of researchers at San Diego State University’s department of Psychology wanted to come up with an explanation for this trend towards lack of adequate sleep. Looking at online presence of teens, the researchers proposed that the large jump from 2009 to 2015 in the percentage of teenagers not getting enough sleep may have been associated with the increasing ubiquity of smartphone use during that time, and for a couple of reasons.

            First, as psychologist Zlatan Krizan hypothesizes, teens may simply be using their phones more often during the day and for longer periods of time, leading to their tendency to sleep for fewer hours at night. This is based on collected data that reported “teens who spent 5 hours a day online were 50% more likely to not sleep enough than their peers who only spent an hour online each day.” In such a media-driven society, 5 hours of smartphone usage is by no means unfathomable, so it is easy to imagine how many adolescents may meet this threshold. Second, Twange comments on the blue light wavelengths emitted by smart phone screens that may “interfere with the body’s natural sleep-wake rhythm,” especially at night.

 With these two concerns in mind, Twenge and her team suggest that teenagers and should consider the amount of sleep they are getting, whether smartphone usage may be a detriment to their sleep schedules, and how they can limit it as such.   


San Diego State University. "More teens than ever aren't getting enough sleep: A new study finds young people are likely sacrificing sleep to spend more time on their phones and tablets." ScienceDaily. ScienceDaily, 19 October 2017.