BackgroundPublished July 21, 20266 min read

Screen Time and Cognition: Does Your Phone Lower Your IQ?

Passive screen time impairs attention, while interactive games and learning can boost some cognitive abilities. Here's the evidence for children and adults.

The screen-time debate is polarised, but the research is more nuanced than the headlines suggest: it is not the screen itself but what happens on it and what it replaces.

What the research shows

A 2019 meta-analysis (Madigan et al., JAMA Pediatrics) linked heavy screen time in young children to worse developmental screening results. The effect is small and largely explained by screens displacing sleep, exercise and interaction.

Type matters

Passive TV viewing correlates with weaker attention. Interactive games that require planning can instead improve spatial ability and working memory.

Children and screens

WHO recommends zero screen time under age 2 and up to one hour per day for ages 2–4. For school-aged children, protecting sleep and study time matters more than a strict total.

Adults and focus

Constant notifications fragment attention and hurt timed fluid tasks like number series. See also the Flynn effect.

Test yourself

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FAQ

Does screen time lower IQ?
It is not the screen itself but what happens on it and what it replaces. Heavy passive TV viewing correlates with weaker attention; interactive games can improve spatial and working memory.
How much screen time is safe for kids?
WHO recommends zero screen time under age 2, and up to one hour per day for ages 2–4. For older children, protecting sleep and homework matters more than a strict total.
Do notifications affect adult IQ?
Yes. Constant interruptions fragment attention and lower performance on timed fluid reasoning. Turning off non-essential notifications is one of the fastest wins.

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