Does a phone on the desk drain your brain? A 33-study answer
A meta-analysis of 33 studies and 4,368 people found no overall effect of a smartphone's mere presence on cognition.
The short version
A widely shared idea holds that simply having your phone nearby — face down, silent, untouched — drains your brainpower. This meta-analysis pooled 33 studies and 4,368 participants and found no meaningful effect of a smartphone's mere presence on cognitive performance. Put the phone away if it tempts you to check it, but not because its presence alone makes you less capable.
What the researchers did
Andree Hartanto and colleagues gathered experiments that manipulated whether a smartphone was present (for example, on the desk versus in another room) and then measured cognitive outcomes such as attention and memory. In total they synthesized 166 effect sizes from 53 samples across 33 studies. Because many studies reported several outcomes from the same participants, they used a four-level meta-analysis — a method that accounts for effects being nested within samples and studies rather than treating them as independent.
What they found
- No overall effect. The pooled effect of a phone's mere presence on cognitive outcomes was essentially zero (d = −0.02, 95% CI −0.06 to 0.01, not statistically significant).
- No moderators. The result did not change with participants' demographics, with how dependent they were on their phones, or with how studies manipulated phone presence and measured cognition.
- A practical conclusion. The authors write that there is little reason at present to think that complete isolation from smartphones in a work environment would improve productivity and performance.
Limits and caveats
A null pooled effect is not proof that no one is ever affected; it means the average effect across these studies is too small to detect. Another meta-analysis of a partly overlapping literature, which also counted studies of phone use, found a small negative effect concentrated in memory tasks (Böttger, Poschik & Zierer, 2023). Lab tasks also differ from real workdays, where a nearby phone is rarely silent. This study says nothing about notifications, which have their own evidence (Kushlev et al., 2016).
What it means for how you work
The phone is still worth managing — but for the alerts and the easy checking, not for a mysterious drain on your mind. Silencing notifications or batching them (Fitz et al., 2019) addresses the part of the problem with real evidence behind it. If keeping your phone within reach helps you feel less anxious about missing something important, this research suggests that is a reasonable trade.