Our brains on multitasking aren’t nearly as good as we think they are. Let’s say you’re working on an activity over here, on the right side of the brain, and suddenly you’re trying to multitask another activity, like talking on the phone.
You’re not actually doing both activities at the same time, in fact, you’re now diverting your attention from one part of your brain to another part of your brain. That takes time, that takes resources, that takes brain cells.
What happens on the other side of the brain is that you’re starting a brand new activity, so in fact you’re probably slower and not nearly as good at doing both activities at the same time.
We can shift our focus really fast, sometimes it takes just a 10th of a second. But the time doesn’t matter as much as the bandwidth the brain requires to move back and forth. Now that might affect your performance, and might also affect the quality of the work that you finally produce.
Take an everyday activity like driving. When you look at the MRI of someone who is in driving mode, see how much of their brain is activating there? Now if you just layer in one more thing—if person is listening while they are driving—and all of a sudden the amount of attention, the amount of brain bandwidth going toward driving decreases by about 37%. So you’re not multi-tasking, you’ve in fact reduced the amount of attention you’re now paying to your driving.
There’s about 2% of the population that are super multitaskers. It’s sort of a genetic gift. Most of us don’t have this gift. But these are people who are truly able to do several different activities at the same time without losing efficiency or losing quality as they do all that work.
This may or may not surprise you, depending on your perspective, but there have been studies that show women are generally better at multitasking than men. Also, people who thought they were the best at multitasking are almost always in fact the worst. Perhaps they were multitasking too much when they thought they were good at multitasking.