Research from Stanford University found that people who are regularly bombarded with several streams of electronic information cannot pay attention, recall information, or switch from one job to another as well as those who complete one task at a time. Multitasking reduces your efficiency and performance because your brain can only focus on one thing at a time.

Brain Damage from Multitasking
Researchers in the UK compared the amount of time people spend on multiple devices (such as texting while watching TV) to MRI scans of their brains. They found that high multitaskers had less brain damage density in the anterior cingulate cortex, a region responsible for empathy as well as cognitive and emotional control. While more research is needed to determine if multitasking is physically damaging the brain, it's clear that multitasking has negative effects.

What Can We Learn?
Multitasking is not a habit you want to indulge in. Even if it doesn't cause the brain damage, allowing yourself to multitask will fuel any existing difficulties you have with concentration, organization, and attention to detail. Multitasking during meetings and other social settings indicates low self- and social awareness, two emotional intelligence skills that are critical for success at work. If multitasking does indeed damage the anterior cingulate cortex of the brain, it will lower your emotional intelligence in the process. So you aren't just harming your performance in the moment, you may very well be damaging an area of your brain that's critical for future success at work too.