A Wandering Mind

In a 2010 study called “A Wandering Mind Is an Unhappy Mind” (gulp), Harvard psychologists Matthew Killingsworth and Daniel Gilbert developed an iPhone app to survey the thoughts, feelings, and actions of five thousand people at any given time throughout a day.

(When a chime went off randomly on the participant’s smartphone, up popped a series of questions that touched on what the person was doing, if he was thinking about what he was doing, and how happy he was, among other things.) From the results of the survey, Killingsworth and Gilbert found that “people are thinking about what is not happening almost as often as they are thinking about what is” and “doing so typically makes them unhappy.”