The fact that they "controlled" for genetics using polygenic scores already is a strong sign of low quality research. Polygenic scores are powerful, but they contain very large amounts of noise compared to the true genetic effects. Controlling for genetics using them is like controlling for income by asking whether the respondents own a Porsche.<p>Also, be aware that Scientific Reports is, if not quite a predatory journal, a very low bar. They publish tens of thousands of articles every year, while charging vast fees.<p>In general, these guys have correlations, not causation. Children's IQ - and gaming habits etc. - develop as they age, so controlling for baseline IQ is not enough to make a correlation with later IQ and gaming causal. It seems much more likely that smarter kids game more, e.g. because they live in richer households. (No, controlling for SES isn't enough to rule this out, for much the same reasons of measurement error as for the genetics.)<p>If you wanna believe that your hours on COD have made you a genius, go ahead, I won't stop you. Just don't imagine that this research proves it.