The idea that we can effectively do several things at once is a myth. Our brains simply aren’t wired to multitask. When we try to do two cognitive tasks at once, like talking on the phone while writing an email, we end up constantly switching between the tasks, reducing our focus and productivity.

Research shows that when we multitask, our brain is really task-switching, which reduces focus and makes us less efficient. Our cognitive resources are limited, so when we allocate them to multiple tasks at once, we’re dividing them up and doing neither task well. Studies using MRI scans show that the parts of our brain involved in task-switching and multitasking overlap with those involved in distraction and mind-wandering.

The costs of multitasking are significant. It reduces our cognitive performance and IQ, impairs learning and memory, and leads to more mistakes and poorer decision making. It also causes higher stress and reduces well-being and life satisfaction. The constant task-switching multitasking demands taxes our brains and mental resources.

While many people believe themselves to be effective multitaskers, the research clearly shows otherwise. Our brains are designed to focus on one thing at a time, and do it well. When we try to do more, we end up constantly reorienting our attention and never focusing fully on any one task. This reduces both the quality and the efficiency of our work.

Single tasking, on the other hand, allows us to focus fully on one thing before moving on to the next. We are able to allocate all of our cognitive resources to the task at hand, leading to better performance, fewer mistakes, and less stress. We feel more satisfied and motivated when we can work without constant interruptions and task-switching.