Inattentional Blindness

Inattentional Blindness

As if all this weren’t enough, we also have to be on guard against something called inattentional blindness. This fancy phrase is what scientists call it when people look right at something and think they are paying close attention, but really aren’t seeing as well as they imagine. Inattentional blindness is the reason it’s not safe to drive while talking on a phone. You can be staring wide-eyed at the road ahead of you, but as your brain devotes itself to the phone conversation, you fail to notice the truck that brakes in front of you or the motorcycle rider who pulls out in front of you.

Scientists Christopher Chabris and Daniel Simons constructed a funny and effective experiment that shows just how easily inattentional blindness cripples our awareness. If you would like to take the test yourself, visit their website and view the brief video before reading the rest of this paragraph (www.theinvisiblegorilla.com/videos.html). What Simons and Chabris have revealed about us would be difficult to believe if they hadn’t repeated the experiment so many times with similar results. Their video shows two teams of people dribbling and passing basketballs. One team is dressed in white shirts, the other in black. Test subjects viewing the video are instructed to count the number of times players in white shirts pass the ball as they move around on the court. That’s it, nothing more. But while test subjects are concentrating and trying their best to keep an accurate count of the passes, a woman in a full-body gorilla suit walks into the middle of the scene, beats her chest, and then casually walks off. To be clear, it’s not some brief, subliminal flash of an image. The gorilla is on screen for a total of about nine seconds. After researchers ask for pass counts, they ask test subjects if they happened to have noticed anything unusual or out of place during the video. Surprisingly, about half of the people who take this test don’t see the gorilla. They fail to notice a hairy gorilla strolling around right in front of their eyes for nine seconds! They are so focused on the ball that their brains fail to recognize and remember the gorilla, even though the ball they are intently tracking with their eyes passes directly in front of the gorilla.

This is inattentional blindness, and it’s a normal, useful feature of our brains. We can’t pay attention to everything all the time, so our brains zoom in on some things while sacrificing broader awareness. The implications ought to be obvious to aspiring skeptics. Not understanding inattentional blindness can lead us to be overconfident in our ability to take in everything around us and not let important things slip by. The truth is, however, we do miss important and unusual details—such as gorillas!

We can’t always be sure that we see everything we need to see in order to make sense of a scene or a situation before us. If someone observes what she thinks is a ghost, for example, the “ghost sighting” might hinge on key details in the scene being left out by her hyper-focused brain. For example, maybe the brain was so locked in on what she thought was a ghost that she failed to notice the lawn lights a few feet away that were shining on the bushes at an angle that formed a light image similar to what popular culture had taught her a ghost is supposed to look like. Inattentional blindness is yet another reason to be skeptical of eyewitness accounts and to always ask for better evidence.