Why Multitasking Actually Makes You Slower, Not More Productive

 

Answering emails during a meeting, checking messages while working on a report, switching between tabs every few minutes, it feels efficient, like getting more done at once. Research on how the brain actually handles this tells a very different story, one that explains why the day can feel busy yet strangely unproductive.

The brain doesn't truly multitask the way most people assume. What feels like doing two things simultaneously is actually the brain rapidly switching attention back and forth between tasks, a process researchers call task-switching. Each switch requires the brain to disengage from one task's context and re-engage with another, and that transition isn't instant or free.

This switching cost is measurable and adds up quickly. Studies on task-switching have found it can take anywhere from several seconds to over 20 minutes to fully regain deep focus after an interruption, depending on the complexity of the task. Someone who checks messages every 10 minutes while working on something demanding is rarely operating at full cognitive capacity, even though it doesn't feel that way in the moment.

Working memory, the mental workspace used to hold information while actively working with it, has a limited capacity that gets strained by frequent switching. Each time attention shifts to a new task, some information from the previous task gets partially or fully dropped from that workspace, which is part of why people often forget what they were about to do after checking their phone mid-task.

Error rates climb measurably during multitasking, not just speed. Tasks that involve multitasking are documented to increase mistakes on both tasks involved, even when the person doing them feels confident and in control the entire time, since the subjective feeling of managing well doesn't match what's actually happening cognitively.

Not all task pairs are equally costly. Switching between two demanding, similar tasks (like writing two different emails) tends to cost more than switching between one demanding task and one automatic one (like folding laundry while listening to a podcast), since automatic tasks require far less working memory.

If a workday feels constantly busy but oddly unproductive, the habit of juggling multiple things at once, rather than a lack of effort or focus ability, is often the more direct explanation. We took a closer look at one approach some people use to support sustained mental focus: check it out here.