Mind Is a Frequent, but Not Happy, Wanderer: People Spend Nearly Half Their Waking Hours Thinking About What Isn’t Going on Around Them
ScienceDaily (Nov. 11, 2010) — People spend 46.9 percent of their waking hours thinking about something other than what they're doing, and this mind-wandering typically makes them unhappy. So says a study that used an iPhone web app to gather 250,000 data points on subjects' thoughts, feelings, and actions as they went about their lives.
...
http://www.sciencedaily.com/releases...1111141759.htm