When you hear the word "daydreaming" you might picture romantic moments, sitting at your desk thinking of a loved one or a far-off place. But Harvard psychologists Matthew A. Killingsworth and Daniel T. Gilbert say that any time your mind wanders — thinking about the past, the future, or anything unrelated to what you're doing in the moment — it counts as daydreaming, and most of it makes a person unhappy. In their study, which used an iPhone app to gather 250,000 data points on subjects' thoughts, feelings, and actions, they found that people's minds wander during 46.9 percent of the time they spend awake. "After answering basic questions about their age, location, and general satisfaction with their job, marriage, or car, iPhone owners could sign up to receive one or more text messages a day," explains an article about the study in Science. "These texts nudged them to visit an online survey to report how happy they were feeling and pick from 22 different choices, including shopping, watching television, or working, to describe what they were doing right then. Subjects also recorded whether they were thinking about that activity or about something else that was pleasant, neutral, or unpleasant." The data also indicated that when a subjects' mind was somewhere else, they were more likely to report being unhappy. "Mind-wandering is an excellent predictor of people's happiness," Killingsworth told the Harvard Gazette. "In fact, how often our minds leave the present and where they tend to go is a better predictor of our happiness than the activities in which we are engaged."
When was the last time your mind wandered? Ten minutes ago? Five? While reading this very sentence? (We took longer to start writing this article than we should have because we couldn't stop daydreaming, either.) According to research published in Science, people spend nearly half their waking hours daydreaming.