Most of us are aware that playing with our phones just before we sleep probably isn’t conducive to a good kip.
Whether that’s down to a flick through Instagram giving us social media angst or being unable to properly switch off from work because we couldn’t stop ourselves spotting that email subject line, looking at a phone last thing at night rarely lulls us into blissful slimber.
And now new research says there’s a link between time spent on our smartphones and our quality of sleep – with every minute of screen time late at night adding up to as much as a minute and a half of lying awake in bed.
The research team analysed data from 653 adults in the US who had completed a survey after having had their screen time monitored via an app (ginger.io) in 30-day windows. It found that on average, people spent 3.7 minutes in every hour on their phones, with younger, female, black, Hispanic and those who described their ethnicity as “other” tending to spend more time with their screens.
From the subset of 136 people who filled out a specific sleep survey, the research found that “(less sleep) and reduced sleep efficiency were each statistically significantly associated with longer average screen-time”.
Further to that, 56 of those people had complete data, which was then analysed to examine how looking at screens at bedtime affects us. The research found that “poor sleep was statistically significantly associated with longer average screen-time during the reported sleeping period and during the hour after bedtime.”
The results conlude: “Longer average screen-time was associated with shorter sleep duration and worse sleep-efficiency.
“Longer average screen-times during bedtime and the sleeping period were associated with poor sleep quality, decreased sleep efficiency, and longer sleep onset latency [the amount of time it takes to transition from full wakefulness to sleep].”
While the team acknowledges that the data doesn’t rule out effect-cause (that people who sleep badly in the first place could be using their smartphones more), as mentioned in the study’s introduction, insomnia and sleep deprivation are on the rise and with our increasing reliance on technology, it’s extremely likely that phones and tablets seriously affect our sleep.
The paper cites the now well-known theory that light in the blue spectrum, such as that produced by electronics, “can suppress production of melatonin leading to decreased drowsiness, difficulty initiating sleep, and non-restorative sleep”. It also points out that the kind of activites we engage in on our phones and tablets likely stimulates our minds instead of relaxing us.
Co-author Gregory Marcus, of the University of California, said that the subgroup of 136 people revealed that on average, every extra minute spent on a phone was linked to a decrease in sleep of approximately five minutes.
And, as theguardian.com reports, for the 56 people analysed for time spent on their phones at bedtime, on average every extra minute on a phone was linked to an added minute and a half to fall asleep.
Marcus said: “I am a big fan of technology and think technology can help us solve many problems.
“However, I think that this suggests that we need to think carefully about how to optimise the use of that technology and understand the consequences of that use.”
Better not be reading this in bed…