Anyone who has ever sat in an online meeting with an email open on the side, a document that needed to be checked “quickly”, and perhaps a chat message popping up, will recognise the feeling. You are busy, but at the end of the meeting, you mainly feel tired. A new study by Frontzkowski and colleagues, published earlier this year in Computers in Human Behavior Reports, shows that this feeling is not merely subjective. Multitasking during video meetings not only makes us more fatigued, it also makes us demonstrably worse at what we do.
That result should not really come as a surprise. Years ago, Paul Kirschner and I published a scientific paper showing that people are cognitively incapable of performing multiple attention-demanding tasks simultaneously. What we call multitasking is, in reality, rapid task switching, with an inevitable loss of quality and efficiency. This insight is now firmly established in cognitive psychology, yet in practice it doesn’t remain easy to act on it, especially in digital environments. And for anyone reading this during an online meeting, you are now facing a small dilemma: keep reading or pay attention.
The new study makes this abstract point very concrete, convincingly combining two complementary studies. In a first experiment, participants had to follow a video meeting and take notes. Half of them were given an additional task at the same time: correcting a text that was presented as urgent. This is not an artificial scenario. It closely resembles how online meetings often unfold in everyday work.
The results are strikingly consistent. Participants who multitasked became more fatigued across almost all dimensions than those who focused on a single task. Not only did general fatigue increase, but so did motivational, emotional and social fatigue. Even visual fatigue increased, although that effect was somewhat less robust. The study shows that multitasking is not a minor side issue, but a clear amplifier of what we now commonly refer to as videoconference fatigue.
Equally important is what happened to performance. Objectively measured, multitaskers performed significantly worse. Their notes were less complete, and they identified far fewer errors in the text. This is precisely what cognitive load theory would predict. Two tasks that both rely on attention, language processing and working memory inevitably compete with each other. The brain cannot solve that problem by simply becoming “more efficient”.
Interestingly, participants seemed to sense this, at least to some extent. Contrary to the popular idea that multitasking creates a false sense of productivity, multitaskers did not rate their own performance higher. In fact, they rated it slightly lower. But this self-criticism was modest compared to the actual drop in performance. People do feel that multitasking is not ideal, yet they systematically underestimate how large the effect really is. This pattern also emerged in our earlier work. The problem is not complete blindness, but systematic underestimation.
The second study, which followed participants over several weeks during real online seminars, confirmed the pattern. Those who multitasked more frequently reported higher levels of general, emotional, social and motivational fatigue. The link with visual fatigue was less pronounced, suggesting that not all forms of fatigue share the same causes. Still, the core message remains unchanged. Multitasking during video meetings is not a neutral choice.
What makes this study particularly strong is that it does not moralise the issue. This is not about a lack of discipline or motivation, but about the limits of the human cognitive system. Video meetings already demand more mental effort than face-to-face conversations. Adding task switching on top of that further increases the load. This turns multitasking during online meetings into a structural stressor rather than an efficiency hack.
For education, policy and organisations, this is not a trivial insight. If online meetings continue to be normalised, we also need to think carefully about how we design them. Clear goals, shorter sessions, and fewer implicit expectations that everyone should be doing “other things” at the same time. Not because people are not trying hard enough, but precisely because they are.
Perhaps that is the most uncomfortable conclusion. Multitasking feels active, necessary and professional. But that feeling hides how costly it actually is. In online meetings, we pay that price not only through poorer performance, but also through fatigue that accumulates, meeting after meeting. And no extra to-do list is going to fix that.