If you're intensely watching a ball game, and a gorilla walks onto the court, you'd notice him ... right? Believe it or not, there's actually a 50 percent chance you'd miss him entirely.
In their new book The Invisible Gorilla, Christopher Chabris and Daniel Simons explain how our brains trick us into thinking we see and know far more than we actually do.
The phrase, "the invisible gorilla," comes from an experiment created 10 years ago to test selective attention. In it, study participants are asked to watch a video in which two teams, one in black shirts and one in white shirts, are passing a ball. The participants are told to count how many times the players in white shirts pass the ball.
Mid-way through the video, a gorilla walks through the game, stands in the middle, pounds his chest, then exits.
Then, study participants are asked, "But did you see the gorilla?" More than half the time, subjects miss the gorilla entirely. More than that, even after the participants are told about the gorilla, they're certain they couldn't have missed it.
"Our intuition is that we will notice something that's that visible, that's that distinctive," explains Simons, "and that intuition is consistently wrong."
Follow-ups to the gorilla study confirmed the findings. "There are sort of whole categories of intuitions, which are not really to be relied on, and that you can go seriously astray by relying on," says Chabris.
"It's true that the kinds of faculties that our minds are filled with right now are very good at solving particular problems that they're designed by evolution to solve," Chabris allows. But today's world is a lot different from the world in which our minds evolved.
Things move much faster now, for example. "When our visual systems evolved, and when our capacities for attention evolved, we didn't move at 60 mph. down highways," so developing brains didn't need to be able to notice a lot of unexpected things approaching at high speeds.
Likewise, Chabris says, "our faculties for making decisions were able to rely on anecdotes and stories, when that was the only information that was available to us." Now that we have statistical studies and databases and all kinds of other information, we aren't as good at making sense of and using information as a guide in our decisions.