According to Stanford professor Clifford Nass, the more you multi-task, the worse you get at it, and it adversely impacts your ability to do all kinds of things a brain should do (like, you know, think).
 

Nass, author of The Man Who Lied to His Laptop: What Machines Teach Us About Human Relationships, offers a number of tidbits in this video interview:

Anything that makes noise or flashes when something happens is designed to distract you and grab your attention. It’s guaranteed to break your concentration and force you to switch tasks. If you are trying to focus, turn them off.

Team building exercises in companies are largely a waste of time. There are very simple things that help us feel bonded with one another.  (Something for me that needs more reflection.)

Us vs. Them is a great impulse in team building. The sense of “us” has a very powerful bonding effect for people. Nass cautions that it has to be thought through. If everyone is “us,” then the sense of team is diluted somewhat.

People that multi-task all the time
•Less able to discern relevant from irrelevant
•Less able to manager their memory
•Less able to switch from task to task

Designing interfaces to encourage multi-tasking is the wrong thing to do because it creates bad thinking.

If you want to check email, you must spend 15 minutes with it. Force yourself to spend longer stretches of time when you switch tasks. This will essentially create a mindset of single-tasking instead.

We know more is coming, we just don’t know always what it will look like.

We can’t have everything. We can’t handle the problem of “more” by doing many things simultaneously. We need to become more discriminating and make harder choices. Specifically, we need to stop saying “yes” to everything, and explicitly decide what we will NOT consume, particularly when new materials become available.

Random reinforcement is the best way to grab your attention – better than regular reinforcement. The brain is just wired that way. Turn off the all those alerts!

Instead, make a conscious decision about what you are going to do in each block of time. At the end of the block scan the possible input streams and possible activities, and focus on that for the next block of time. Nass suggests that those blocks are 15-30 minutes.

The more you try the multi-task the worse you are at it. By focusing in blocks of time, when you do nee to multi-task you will be better at it.