The impact of digital media on children's intelligence while controlling for genetic differences in cognition and socioeconomic background

Digital media defines modern childhood, but its cognitive effects are unclear and hotly debated. We believe that studies with genetic data could clarify causal claims and correct for the typically unaccounted role of genetic predispositions. Here, we estimated the impact of different types of screen time (watching, socializing, or gaming) on children's intelligence while controlling for the confounding effects of genetic differences in cognition and socioeconomic status. We analyzed 9855 children from the USA who were part of the ABCD dataset with measures of intelligence at baseline (ages 9-10) and after two years. At baseline, time watching (r = - 0.12) and socializing (r = - 0.10) were negatively correlated with intelligence, while gaming did not correlate. After two years, gaming positively impacted intelligence (standardized beta = + 0.17), but socializing had no effect. This is consistent with cognitive benefits documented in experimental studies on video gaming. Unexpectedly, watching videos also benefited intelligence (standardized beta = + 0.12), contrary to prior research on the effect of watching TV. Although, in a posthoc analysis, this was not significant if parental education (instead of SES) was controlled for. Broadly, our results are in line with research on the malleability of cognitive abilities from environmental factors, such as cognitive training and the Flynn effect.

Automated summary

Digital media has an impact on modern childhood, but its cognitive effects are debated. This study used genetic data to investigate the influence of different types of screen time on children's intelligence, controlling for genetic differences and socioeconomic status. The findings showed that watching and socializing time were negatively correlated with intelligence, while gaming time had a positive impact on intelligence. These results align with experimental studies on video gaming, but contradict prior research on the effect of watching TV.