„PISA defines children as ‚extreme Internet users‘ when they spend more than 6 hours online per day outside school. In 2015, 16 % of 15 year olds among OECD countries could be considered ‚extreme Internet users‘ during weekdays, and 26 % during weekends. ‚Extreme Internet users‘ reported less life satisfaction and were more likely to be bullied at school. […] ‚Extreme Internet users‘ performed worse across all subjects in the PISA test, even after accounting for differences in socio-economic backgrounds.“
Julie Hooft Graafland, „New technologies and 21st century children“ (2018), S. 12