> Your "better" study is not an experiment and its conclusions are not supported by empirical evidence. I think their method does count as a natural experiment

> Your "better" study is not an experiment and its conclusions are not supported by empirical evidence. I think their method does count as a natural experiment and as such does have empirical evidence. From the article: “Preschoolers from a 2010 study (612 children) were compared to preschoolers from a 2014 study (492 children) because of the digital explosion into everyday life that occurred between the two time periods. Television viewing patterns have remained similar over time, but technological device usage has increased.” > If it were true that usage of touchscreens cause lower intelligence test scores, we would have seen this show up as a population-wide reduction in scores as touchscreens became widely available. Exposure in formative years is vastly different than adult exposure. The affected cohort in the study is now only in middle school and population wide effects will have a lagged appearance.