Although most of us recoil at the idea of “busywork,” such mindless tasks can boost our mood—as long as we have an excuse to perform them, according to a study in the July issue of Psychological Science.

Psychologists at the University of Chicago and Shanghai Jiaotong University offered subjects a choice between rebuilding a beaded bracelet or sitting idly during a 15-minute wait. Most chose to sit idly—unless they were given the chance to rearrange the beads instead of to rebuild it as it was. In another experiment, subjects filled out a survey and then had a choice either to turn it in to the assistant in the room and then wait, doing nothing, until the next part of the experiment could begin, or they could kill the time by walking the survey over to another building to turn in. In all cases, the students were offered a candy when they turned in their survey, but only when the candies in each location differed did more students opt to take the walk. The results were the same no matter which type of candy was offered in either location, suggesting that the students were choosing the distant candy simply to rationalize taking the walk.

The results of both experiments suggest that when there is an excuse, such as doing something artistic or getting a different reward, people like to keep busy—and indeed, those who chose the busier option reported feeling happier afterward, on average, than those who did nothing. The researchers suggest that next time you’re waiting around for something to happen, think of a reason to keep yourself busy—even simple activities such as taking a walk or organizing a closet could boost your mood.