Multitasking makes you more productive
The brain lacks the architecture to perform two cognitively demanding tasks simultaneously. Task-switching, which is what multitasking actually involves, creates mental switching costs that reduce efficiency and increase errors.
What we know
The human brain does not process two complex tasks in parallel. When people report multitasking, they are actually switching rapidly between tasks, engaging what cognitive scientists call task-switching. Each switch requires the brain to shift goals and rules, incurring a 'switch cost' that manifests as slower performance and higher error rates. The American Psychological Association cites research showing that these costs can accumulate to eliminate as much as 40 percent of productive time in people who switch frequently.
A 2019 review published in the Dana Foundation's Cerebrum journal summarized the neuroscience clearly: the brain regions that support sustained attention and working memory, including the prefrontal cortex and parietal areas, are taxed by task-switching in ways that impair performance on both tasks. Importantly, heavy multitaskers tend to perform worse not only when switching but also during single tasks requiring sustained attention, suggesting that habitual media multitasking may have lasting effects on cognitive control.
A 2024 review in Annals of Medicine and Surgery linked chronic digital multitasking to increased anxiety, depression, and reduced working memory capacity among frequent multitaskers. The mechanism is understood: cognitive load from managing multiple task sets depletes limited working memory resources, leaving less capacity for any individual task.
The one real advantage of multitasking is in combining a cognitively demanding task with an automatic one, such as listening to an audiobook while walking. Simple, well-practiced tasks that require minimal cognitive resources can coexist with more demanding activities without significant cost. The productivity-enhancing claim about multitasking refers to this limited exception, not to juggling multiple complex tasks simultaneously.
Common claims
- Doing multiple things at once saves time.False. Task-switching costs outweigh any apparent time savings for complex tasks.
- Some people are natural multitaskers who suffer no cognitive cost.False. Heavy multitaskers typically perform worse on sustained-attention tasks.
- Multitasking simple tasks with complex ones is efficient.Partly true. Automatic tasks paired with demanding ones carry lower switching costs.