There’s a famous experiment where two teams, one dressed in white and one dressed in black, pass a basketball. Participants count the number of times the team in white passes the ball. More than half of people fail to notice when a person in a gorilla suit crosses the field thumping his chest because they’re so concentrated on the task at hand. The experiment shows how little we notice of our surroundings and how we’re inattentionally blind.
Of course, these days, the invisible gorilla is so famous that ninety percent of us are on the lookout for it. Daniel Simon, the cognitive psychologist who set up the original study in 1999, thought it would be interesting to see if he could monkey with people’s intuition again, using almost the same task. Try out his test in the video below.
Did you make it? There are two competing predictions in the test. Knowing about the invisible gorilla might increase your chances of noticing other unexpected events because you know that the task tests whether people spot unexpected events. Alternatively, knowing about the gorilla might lead you to look exclusively for gorillas and miss anything else that’s going on.
Of the 41 volunteers Simon tested who had never heard about the old gorilla video, a little less than half missed the gorilla in the new video. The 23 volunteers he tested who knew about the gorilla in the old video, all spotted it in the new video. However, just 17 percent noticed the other unexpected events in the new video. It shows that we often miss things that we don’t expect to see. Or, once we find what we’re looking for, we stop noticing everything else.