Time spent in front of a screen is part of the modern child’s everyday life. Children aged 8 to 12, for example, spend an average of 4 to 6 hours each day watching videos, gaming and socializing using the screens of their digital devices. Although digital media brings a variety of new experiences to children, it is not known what the effects of these experiences are on the developing minds and cognitive abilities of young people. Although much research has been done, this topic remains hotly debated.
A recent study by researchers from the Karolinska Institutet in Sweden has focused specifically on the impact of screen time on children’s intelligence, in particular their ability to learn effectively, think rationally, understand complex ideas, and adapt to new situations. The researchers used a sample of just over 9,000 US boys and girls, aged 9 to 10, to investigate how screen habits correlate with the development of cognitive abilities over time.
The team identified three different types of screen time usage: time spent watching TV and online videos; time spent socializing via social media, text, and video chat; and time spent gaming. They estimated the effect of each type of activity on intelligence after accounting for the critical confounding influences of genetic and socioeconomic backgrounds.
At the age of nine or ten, the children performed a battery of psychological tests to gauge their general cognitive abilities (intelligence). The children and their parents were also asked about how much time the children spent watching TV and videos, playing video games and engaging with social media. Then, two years later, just over 5,000 of the children repeated the cognitive tests. This allowed the researchers to study how the children’s performance on the tests varied from the one testing session to the other, and to control for individual differences in the first test.
The results, published in the journal Scientific Reports, showed that the children spent an average of 2.5 hours a day watching TV, half an hour on social media and one hour playing video games. They also showed that gaming positively impacted the amount of change in intelligence between the two sets of tests, so that children who played more video games at 9 to 10 years showed the greatest gains in intelligence two years later. Children who played more games than average showed an increase in their intelligence scores of approximately 2.5 IQ points more than the average increase.
This result was the same for boys and for girls. Surprisingly, watching TV also showed a positive effect on the change in intelligence but, less shockingly, socializing had no effect on cognitive change. No significant effect was observed, positive or negative, for TV-watching or for social media use.
“We didn’t examine the effects of screen behavior on physical activity, sleep, wellbeing or school performance, so we can’t say anything about that,” said Torkel Klingberg, professor of cognitive neuroscience at the Department of Neuroscience, Karolinska Institutet. “But our results support the claim that screen time generally doesn’t impair children’s cognitive abilities, and that playing video games can actually help boost intelligence. This is consistent with several experimental studies of video-game playing.”
A fascinating finding of the study is that intelligence is not a constant but can vary during a person’s lifetime. This is in line with other recent research showing that intelligence is not fixed, but is influenced by environmental factors. More profoundly, the positive cognitive impacts of watching videos and playing video games could partially explain the worldwide gradual increase in intelligence scores over the decades, known as the Flynn effect. The authors state that it is probably not a coincidence that the introduction of video games and computer technologies in the 1970s and 1980s coincides with a slight but discernible increase in the measured rate of increase in IQ scores.
“We’ll now be studying the effects of other environmental factors and how the cognitive effects relate to childhood brain development,” said Professor Klingberg.
One limitation of the study is that it only covered US children and did not differentiate between different types of video games, which makes the results difficult to transfer to children in other countries with other gaming habits. There was also a risk of reporting error since screen time and habits were self-rated.