The Stanford team compared groups of people based on their tendency to multitask and their belief that it helps their performance. They found that heavy multi-taskers were actually worse at multitasking than those who like to do a single thing at a time. The frequent multi-taskers performed worse because they had more trouble organising their thoughts and filtering out irrelevant information.
They were also slower at switching from one task to another. "Multi-tasking reduces your efficiency and performance because your brain can only focus on one thing at a time," the authors wrote.
When you try to do two things at once, your brain lacks the capacity to perform both tasks successfully.
The team also showed that in addition to slowing you down, multi-tasking lowers your IQ, entrepreneur.com reported
Another study from University of London found that participants who multi-tasked during cognitive tasks experienced IQ score declines.
The IQ drops of 15 points for multitasking men lowered their scores to the average range of an eight-year-old child.
While more research is needed to determine if multi-tasking is physically damaging the brain, it is clear that multi-tasking has negative effects.
Multi-tasking in meetings and other social settings indicates low self- and social awareness - two emotional intelligence (EQ) skills that are critical to success at work.
Source | http://www.hindustantimes.com/wellness/multi-tasking-21st-century-style-bad-for-your-brain-could-damage-it/article1-1332042.aspx