Tatiana Íñiguez Berrozpe
This is a methodologically very sound article. It is a review of reviews that brings together 23 meta-analyses and compiles data on nearly three million children from 64 countries; the sample is therefore extremely large. It has been pre-registered, assesses the quality of the studies it includes and – a rare and methodologically sound practice – excludes studies that appeared in multiple meta-analyses, thereby preventing the results from being inflated. Furthermore, the authors also report on data that did not prove to be statistically significant, which lends transparency and scientific rigour to the study as a whole.
However, the main findings confirm what research has been showing for years and which puts the current media and social moral panic surrounding the relationship between young people and screens into perspective: there is an association between screen time and poorer indicators of mental health and academic performance, but it is very small (around 1 per cent of the differences between one group of adolescents and another). This is not an insignificant finding, but it in no way supports the mantra that screens are the main cause of adolescent emotional distress. As we have pointed out in previous articles, screen use alone does not explain why a teenager is emotionally distressed or performs worse academically.
Other caveats to bear in mind when reading the results are as follows: firstly, some striking findings, such as emotional problems or difficulties with peers, are based on very few studies and show significant variability between them. Their confidence intervals range from an almost negligible effect to a moderate one, so these are the least reliable estimates in the article, and they are the ones most likely to make headlines in the media, as is often the case. Secondly, the authors compare the magnitude of these effects with that of socio-economic status, and this comparison must be treated with caution, as studies on screen use typically do not use socio-economic status as a variable to adjust their results. Moreover, as argued by some in contemporary educational sociology, we might consider that some of what is attributed to screen use may, in reality, be social inequality expressed through these devices.
Perhaps the most novel aspect of the study lies in the distinctions it draws between different types of screen use. For example, the association between such use and psychological distress in children is stronger with mobile phones than with television or video games, and stronger with depressive symptoms than with social anxiety. Furthermore, this association is more pronounced in adolescents than in younger children. All of this delves into another issue that has been highlighted by the latest research on the subject: it matters less how many hours devices are used for and more which device is used, for what purpose, with whom and at what stage of development. Recommendations based solely on total hours lump together very different types of use, as playing online with friends or doing homework is not the same as passively scrolling for hours through a feed designed to hold one’s attention.
Another limitation worth noting is that, as is often the case in such studies, most of them are cross-sectional and do not allow for the establishment of causality, only association.
Finally, it is worth highlighting another issue commonly raised in studies of a more sociological nature than the one at hand—although this study clearly demonstrates it: the most significant factor in the association between children and screen time is the time spent scrolling. In other words, the problem is not screen use itself, but rather what I fail to do whilst immersed in it, such as sleeping, engaging in physical activity, or socialising with family and friends.