Notice Anything Different?

April 21, 2011
Posted by Jay Livingston

It’s sitcom cliche – the man failing to notice that his wife or girlfriend is now blond instead of brunette or that the living room walls, once a pale gray, are now day-glo orange.

It may be a cliche, one bursting with gender stereotyping, but the phenomenon is real. It’s called “change blindness.” All it means is that we ignore aspects of the setting that aren’t important to us, so we don’t notice when they change. If we had to remember every little detail in every encounter and setting, we’d never get anything done. What’s surprising is how huge the changes can be yet still go unnoticed .

In a psychology experiment by Daniel Simons, subjects turn in their release form at a counter. The assistant behind the counter takes the form, ducks down behind the counter to get another piece of paper, and when he reappears a second later, he’s a different person.


Three-fourths of the subjects didn’t notice that the guy on the left had become the guy on the right. The voiceover on the video says that the differences between the men are “obvious.” “Their faces are different, their hair is different, even their shirts are a different color.”

But they are the same race, the same age, roughly the same height and build, and their shirts are the same Ivy-league uniform – pale, button-down, Oxford cloth. I’m impressed that 25% of the subjects did notice.

In Simons’s “door experiment,” one person asking directions is replaced by another.
Again, they don’t look so different (a video is here )

Outside of academia, Candid Camera style TV versions show just how far you can take this sort of thing. Derren Brown, a sort of British Penn Jillette, though much less abrasive, does a version of the door experiment with the transformations getting more and more exaggerated (video here, not embeddable). It ends with this – as different as Black and White.

And then there’s the Japanese version. The switcheroo is unmistakeable, nor is there any attempt at misdirection by focusing the person’s attention on a map. The victims of the prank are asked to point the camera directly at the two young girls, who then become two old men So people do notice. But to befuddle them further, the experimenters add a gaffed Polaroid camera.

The victims are confused, obviously. But if you didn’t reveal the gag and you asked them a few days later what they remembered of it, would they adjust their memories to make the events consistent with the law of conservation of reality?:Does change blindness go both forwards and backwards in time? Is the impulse towards retrospective interpretation strong enough to overcome such a huge difference?

Then there’s the question crucial for the issue of eyewitness testimony: would they forget the most important detail – the car?