I just read this article about how multi-tasking is making us less efficient.
I have a friend whose work philosophy was work your way through the pile, one paper at a time. This was a very efficient person who used to get lots and lots accomplished but not someone you would ever consider a multi-tasker. My friend may have been on to something.
I have a different friend who claims to have Attention Deficit Hyperactivity Disorder - whines about it quite frequently actually.
Perhaps this friend is showing signs of a new condition identified as "Attention Deficit Trait".
Read about it here - The Myth of Multitasking"