In a paper being presented to the British Educational Research Association (BERA) by researchers at WISERD, the report also reveals that more than a third of 12- to 15-year-olds say they do so at least once a week.
Unsurprisingly, this is revealed to be having knock-on effects on how tired the youngsters feel at school: among some children it may even be more important than having a late bedtime in creating feelings of fatigue.
The sleep-disrupting use of social media at night also seems to be impacting on pupils’ overall happiness, with lower levels of wellbeing reported by those who wake to use social networks.
Meanwhile, the study also has implications for the debate on whether teenagers should be allowed to start school later, to give them more time to sleep in the morning. The research team say their data suggest such a change could do more harm than good.
The team’s findings on teenage sleep patterns are drawn from statistical analysis of a survey of 412 pupils in year eight (aged 12 and 13) and 436 pupils in year 10 (aged 14 and 15), educated in secondary schools across Wales.
The adolescents were asked how often they wake at night to use social media. Some 22 per cent of year eight pupils, and 23 per cent among those in year 10, answered “almost always”.
A further 14 per cent of the younger group, and 15 per cent of the older, said they did so at least once a week.
Those surveyed were also asked how often they felt tired at school. More than half of those who reported “almost always” waking to use social media also said they “almost always” go to school feeling tired.
This was much higher than the overall percentage of respondents saying they “almost always” feel tired at school, which was 32 per cent among year 8 pupils and 39 per cent among year 10s.
The study found substantial proportions of pupils reporting going to bed very late: 17 per cent of year eight and 28 per cent of year 10s said they put their heads down at midnight or later on a school night. Among these, six per cent of the younger group and 8 per cent of the older claimed to go to bed later than 1am.
However, the study found that, in the case of the younger group, the amount of time spent in bed actually seemed less important, in terms of whether the child then reported feeling tired at school, than whether they woke up during the night to use social media.
This was not the case among the older group. However, even among this group, those saying they woke up to use social media every night were still twice as likely to say they were constantly tired than those who never did so.
The researchers also found a strong association between pupils reporting having a regular time when they woke up in the morning and not feeling tired.
WISERD’s Dr Kimberly Horton, who is presenting research on Wednesday, said: “Having a regular waketime and using social media during the night appear to be more important in determining whether a young person is always tired during the day than the time they go to bed, how long they spend in bed and having a regular bedtime.
“It seems [very] important to discourage adolescents from using social media during the night. No amount of effort to develop regular bedtimes or to lengthen the time in bed would seem to be able to compensate for the disruption that this can cause.”
Last week, Paul Kelley, a former headteacher now working at Oxford University’s Sleep and Circadian Neuroscience Institute, told the British Science Festival that school start times should be put back to combat sleep-deprivation among pupils.
But the WISERD paper argues against later school start times. It says that pupils would be less likely to have regular waking times as a result, re-iterating that routine waking times seemed from the survey data to be very important in terms of making a child less likely to feel tired.
The paper says: “Having a regular morning routine may actually prove to be a very important feature in helping adolescents concentrate and enjoy their learning, something that may actually be undermined by changes to the school day.”
Sleep patterns also seem to have a clear impact on pupils’ overall reported level of wellbeing. The pupils were asked how happy they were, on a scale of one to seven. Among the younger pupils, those who reported nearly always feeling tired were nearly a point less happy on average, while among the older group, those reporting as nearly always tired were half a point less happy.
“Routines and rest: the sleep behaviours of 12 to 15 year olds”, a paper by Dr Kimberley Horton, Professor Chris Taylor and Professor Sally Power, all of the Wales Institute of Social and Economic Research, Data and Methods and Cardiff University, is being presented to BERA on Wednesday, September 16th.