Member-only story
You Have No Idea How Much Your Brain Is Ignoring
The eye-opening science behind ‘inattentional blindness’
In an iconic study from 1999, Daniel Simons and Christopher Chabris, researchers at Harvard University, used a gorilla costume as a prop to explore visual perception.
Subjects were asked to watch a video and count the number of times players passed a basketball between a small, continually moving group of students. Partway through the video, a person dressed in a gorilla suit slowly walked into the frame, beat their chest, and walked off.
When Simons first tried the test with Harvard University students, he held his breath, but despite the gorilla being visible for nine seconds, only half of them noticed the unlikely walk-on. “Missing the gorilla is jarring. It’s natural to assume that you would see it, so it’s surprising and compelling when you realize what you’ve missed,” he says.
The study was repeated in 2010, but this time it included subjects who were aware of the original video and its findings regarding unexpected objects. Though they identified the gorilla in the new film, they failed to notice other significant changes, including the backdrop’s color (shifting from red to gold) and a player walking off the court.
So, what is failing in us? Perhaps nothing.
For excellent evolutionary reasons, people have a remarkable ability to focus on what appears, in the moment, to be essential. A person tracking an antelope or avoiding a lion needs to be fully committed — distraction is not an option. Despite the apparent survival benefits of this hyper focus, people may be unaware of significant chunks of their surroundings.
“We remember vividly all the times we have noticed something unexpected or unusual, but have no idea how many times we have missed gorillas or unicycling clowns, unless a researcher explicitly brings it to our attention.”
This phenomenon, labeled “inattentional blindness” by cognitive scientists, occurs in response to a perceptual framework evolved by humans over thousands of years.
