10 votes

The impact of digital media on children’s intelligence

3 comments

  1. [2]
    skybrian
    Link
    This is one of those cases where the study looked good to me when I read it, but then I read criticisms that made me realize that I simply don’t know enough to spot the flaws. In particular, gwern...

    This is one of those cases where the study looked good to me when I read it, but then I read criticisms that made me realize that I simply don’t know enough to spot the flaws.

    In particular, gwern commented on Hacker News.

    Yes, the polygenic score, when used to define 'genetic intelligence', will be biased towards zero and will miss a lot of the genetic intelligence. What then happens is the video-game playing becomes a measure of intelligence (genetic or otherwise), capturing what the polygenic score (and other covariates) miss. The logic then works in reverse: the reduced correlation is precisely why the residual confounding works. The worse your 'measurements' are at measuring the underlying trait, the more wiggle room there is for your 'outcomes' to actually be correcting the 'measurements' and not vice versa. See "Statistically Controlling for Confounding Constructs Is Harder than You Think" https://journals.plos.org/plosone/article?id=10.1371/journal... , Westfall & Yarkoni 2016. (More examples: https://www.gwern.net/notes/Regression )

    What OP shows is not that video game playing causes IQ, but IQ causes video game playing. The choice to play video games (or not play them, because you are bad at learning) is an additional 1-item long IQ test and helps corrects for the error.

    (Also, I’ll make the usual warning that Scentific Reports is not Nature and has a much worse reputation, so don’t be fooled by the domain name.)

    8 votes
    1. mtset
      Link Parent
      Interesting and probably right, but I think gwern (🙄) and many others are missing the point; the interesting thing here, to me, is that "screen time" is a meaningless concept. Looking at art on a...

      Interesting and probably right, but I think gwern (🙄) and many others are missing the point; the interesting thing here, to me, is that "screen time" is a meaningless concept. Looking at art on a screen does not hurt you, except in that it can mess up your vision over a long period of time if you don't rest your eyes.

      3 votes
  2. mtset
    Link
    Among 9855 children starting at ages 9-10:

    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.

    Among 9855 children starting at ages 9-10:

    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 β =  + 0.17), but socializing had no effect. This is consistent with cognitive benefits documented in experimental studies on video gaming.

    7 votes