Does the Mere Presence of a Smartphone Make You Dumber?

Hint: Nope.

Social media debates continue to storm along, particularly in the US, where numerous lawsuits and legislation continues to swirl.  This year, social media had a big win in the US Supreme court, which ruled that governments couldn’t force social media companies to take a particularly political view.  How this might apply to the social media = harm cases has yet to be seen.  As I’ve covered before in other places the evidence social media impacts mental health is pretty weak.

A parallel argument I see come up sometimes is that the mere presence of a smartphone makes people less cognitively able.  The general gist seems to be that even having a smartphone nearby is distracting enough to impede school, work, or other cognitive tasks.  But is this true?

To address this Douglas Parry published a meta-analysis in November 2023, examining the existing studies that had considered this hypothesis.  This included 56 effect sizes, involving 7093 research participants overall.

The good news is that for most cognitive outcomes, the presence of a smartphone had no impact.  These outcomes included sustained attention, inhibitory control, cognitive flexibility, and fluid intelligence.  So, all good there, smartphone or not.

The only “statistically significant” finding was for working memory, but even here I find the results to be ambiguous at best.  Almost all meta-analyses return “statistically significant” results…in fact it’s rather remarkable this particular meta-analysis had so many non-significant findings.  The whole concept of “statistical significance” in meta-analysis is largely nonsense, though unfortunately too many social scientists continue to fall for it. 

The effect size for the impact of smartphones on working memory was very small (d = -.199).  This is juuuuuust below the threshold I advocate for being minimally hypothesis supportive (d = .21).  This is because effect sizes below that level of d = .21 tend to have a high false positive or noise rate, meaning we can’t distinguish true effects from methodological noise/crud.  In this case, it’s right on that border, but I’d say overall this doesn’t provide compelling evidence that smartphones cause any impact on working memory we’d need to worry about.  Particularly as the author indicates there may be some publication bias in this set of experiments, I think the cautious interpretation is the correct one.

Overall, it’s a pretty good meta-analysis.  My main critiques are the over-focus on “statistical significance” and we need to get better about not overinterpreting tiny effect sizes.  But this is a discipline wide problem, not a unique problem for this meta-analysis.    

But, so no…smartphones don’t seem to cause people cognitive problems by merely being present.