The research: University of Melbourne researchers Kate Lee, Kathryn Williams, Leisa Sargent, Nicholas Williams, and Katherine Johnson gave 150 subjects a menial task that involved hitting specific keystrokes when certain numbers flashed on a computer screen. After five minutes the subjects were given a 40-second break, and an image of a rooftop surrounded by tall buildings appeared on their screens. Half the subjects saw a plain concrete roof; the others saw a roof covered with a green, flowering meadow. Both groups then resumed the task. After the break, concentration levels fell by 8% among the people who saw the concrete roof, whose performance grew less consistent. But among those who saw the green roof, concentration levels rose by 6% and performance held steady.
A version of this article appeared in the September 2015 issue (pp.32–33) of Harvard Business Review.