Extra hour of screen time per day associated with poorer GCSE grades

September 3, 2015
Credit: Paul Brennan/public domain

An extra hour per day spent watching TV, using the internet or playing computer games during Year 10 is associated with poorer grades at GCSE at age 16 - the equivalent of the difference between two grades - according to research from the University of Cambridge. In a study published today in the open access International Journal of Behavioral Nutrition and Physical Activity, researchers also found that pupils doing an extra hour of daily homework and reading performed significantly better than their peers. However, the level of physical activity had no effect on academic performance.

The link between and health is well established, but its link with academic achievement is not yet well understood. Similarly, although greater levels of sedentary behaviour - for example, watching TV or reading - have been linked to poorer physical health, the connection to academic achievement is also unclear.

To look at the relationship between physical activity, sedentary behaviours and academic achievement, a team of researchers led by the Medical Research Council (MRC) Epidemiology Unit at the University of Cambridge studied 845 pupils from secondary schools in Cambridgeshire and Suffolk, measuring levels of activity and sedentary behaviour at age 14.5 years and then comparing this to their performance in their GCSEs the following year. This data was from the ROOTS study, a large longitudinal study assessing health and wellbeing during adolescence led by Professor Ian Goodyer at the Developmental Psychiatry Section, Department of Psychiatry, University of Cambridge.

The researchers measured objective levels of activity and time spent sitting, through a combination of heart rate and movement sensing. Additionally the researchers used self-reported measures to assess (the time spent watching TV, using the internet and playing computer games) and time spent doing homework, and reading for pleasure.

The team found that screen time was associated with total GCSE points achieved. The average (median) amount of screen time per day was four hours: an extra hour per day of time spent in front of the TV or online at age 14.5 years was associated with 9.3 fewer GCSE points at age 16 years - the equivalent to two grades, for example from a B to a D. Two extra hours was associated with 18 fewer points at GCSE.

Screen time and time spent reading or doing homework were independently associated with , suggesting that even if participants do a lot of reading and homework, watching TV or online activity still damages their academic performance.

The researchers found no significant association between moderate to vigorous physical activity and academic performance, though this contradicts a recent study which found a beneficial effect in some academic subjects. However, both studies conclude that engaging in physical activity does not damage a pupil's academic performance. Given the wider health and social benefits of overall physical activity, the researchers argue that it remains a public health priority both in and out of school.

As well as looking at total screen time, the researchers analysed time spent in different screen activities. Although watching TV, playing computer games or being online were all associated with poorer grades, TV viewing was found to be the most detrimental.

As this was a prospective study (in other words, the researchers followed the pupils over time to determine how different behaviours affected their ) the researchers believe they can, with some caution, infer that increased screen time led to poorer academic performance.

"Spending more time in front of a screen appears to be linked to a poorer performance at GCSE," says first author Dr Kirsten Corder from the Centre for Diet and Activity Research (CEDAR) in the MRC Epidemiology Unit at the University of Cambridge. "We only measured this behaviour in Year 10, but this is likely to be a reliable snapshot of participants' usual behaviour, so we can reasonably suggest that screen time may be damaging to a teenager' grades. Further research is needed to confirm this effect conclusively, but parents who are concerned about their child's GCSE grade might consider limiting his or her screen time."

Unsurprisingly, the researchers found that teenagers who spent their sedentary time doing homework or reading scored better at GCSE: pupils doing an extra hour of daily homework and reading achieved on average 23.1 more GCSE points than their peers. However, pupils doing over four hours of reading or homework a day performed less well than their peers - the number of pupils in this category was relatively low (only 52 participants) and may include participants who are struggling at school, and therefore do a lot of homework but unfortunately perform badly in exams.

Dr Esther van Sluijs, also from CEDAR, adds: "We believe that programmes aimed at reducing screen time could have important benefits for teenager' exam grades, as well as their health. It is also encouraging that our results show that greater physical activity does not negatively affect exam results. As physical activity has many other benefits, efforts to promote physical activity throughout the day should still be a public health priority."

Explore further: High levels of physical activity linked to better academic performance in boys

Related Stories

High levels of physical activity linked to better academic performance in boys

September 11, 2014
A recent Finnish study shows that higher levels of physical activity are related to better academic achievement during the first three school years particularly in boys.

Weekend screen time linked to poorer bone health in teen boys

June 10, 2015
Weekend screen time is linked to poorer teen bone health—but only in boys, reveals research published in the online journal BMJ Open.

Sitting time not associated with poorer diets in US adults

July 16, 2015
Previously identified associations between TV viewing and a less healthful diet may stem from exposure to advertisements of high calorie foods and 'distracted eating' rather than the activity of sitting itself, although sitting ...

Do video games, phones and the internet impact children's cognition?

October 7, 2014
Children have an increasing attraction towards electronic media in their play. With video games, phones and the internet in abundance, this article in Educational Psychology examines if such leisure activity is impacting ...

Five year-olds who watch TV for 3+ hours a day more likely to be antisocial

March 25, 2013
Five year-olds who watch TV for three or more hours a day are increasingly likely to develop antisocial behaviours, such as fighting or stealing by the age of seven, indicates research published online in Archives of Disease ...

The case against unlimited screen time for children

July 23, 2015
PLOS Blogs colleague Beth Skwarecki has a post this week on the potential benefits of screen time for kids. It's makes points that are similar to those brought up by former PLOS Blogger Melinda Wenner Moyer over at Slate ...

Recommended for you

To combat teen smoking, health experts recommend R ratings for movies that depict tobacco use

July 21, 2017
Public health experts have an unusual suggestion for reducing teen smoking: Give just about any movie that depicts tobacco use an automatic R rating.

Aging Americans enjoy longer life, better health when avoiding three risky behaviors

July 20, 2017
We've heard it before from our doctors and other health experts: Keep your weight down, don't smoke and cut back on the alcohol if you want to live longer.

Opioids and obesity, not 'despair deaths,' raising mortality rates for white Americans

July 20, 2017
Drug-related deaths among middle-aged white men increased more than 25-fold between 1980 and 2014, with the bulk of that spike occurring since the mid-1990s when addictive prescription opioids became broadly available, according ...

Parents have critical role in preventing teen drinking

July 20, 2017
Fewer teenagers are drinking alcohol but more needs to be done to curb the drinking habits of Australian school students, based on the findings of the latest study by Adelaide researchers.

Fresh fish oil lowers diabetes risk in rat offspring

July 19, 2017
Fresh fish oil given to overweight pregnant rats prevented their offspring from developing a major diabetes risk factor, Auckland researchers have found.

High-dose vitamin D doesn't appear to reduce the winter sniffles for children

July 18, 2017
Giving children high doses of vitamin D doesn't appear to reduce the winter sniffles, a new study has found.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.