A while ago, I recall watching a documentary (might have been quite a light-hearted, entertainment-type show) where it was demonstrated that people don’t notice if a stranger changes identity midway through a conversation.
The way it worked was that one person struck up conversation with a stranger (asking directions or advice of some such). Midway, a couple of stooges carrying a sheet of ply just happen to walk between the two people, at which point, the person who initiated the conversation was replaced by a different individual - primed to continue on as if they’d been there all along.
It supposedly turned out in many cases that the subject didn’t notice the change - even if the second person was dressed differently, or even (if I recall correctly) a different race or gender.
Trouble is, I can’t seem to work out any useful keywords for finding a write-up or video version of the experiment.
Can anyone remember what it was called?
(BTW, I’m already aware of the similar ‘mannequin head drop’ prank)
I watched all the the related videos and have to say that I’m not surprised at all. My husband can shave his goatee, and it takes up to four days for me to notice. The shame.
Reminds me of the film That Obscure Object of Desire during the course of which the actress playing the lead character gets switched out for another actress, and the two actresses keep alternating in different scenes. Although the actresses only superficially resemble each other, most viewers don’t notice the switch at first and some don’t notice it at all.
I remember seeing a card trick video linked on James Randi’s site once that demonstrated this. The backdrop, table cloth and performers’ clothes all changed several times but went unnoticed if you were concentrating on the card trick. Wish I’d kept the link!
It is probably one of these, and almost certainly an experiment done by those guys (who, incidentally, were really just ripping off work done by Ulric Neisser and his student Becklen back in the early '70s). “The Invisible Gorilla” is the most famous of these videos, but Simmons and Chabris did lots of other similar experiments.
Actually, “The Invisible Gorilla” is technically a demonstration of inattentional blindness rather than change blindness, but they are closely related phenomena, and both quite surprising to most people when they first experience them. Change blindness, however, can probably be induced in a wider variety of ways. There are also a bunch more change blindness demos, mostly animated gifs, which induce the effect in various ways, on J.K. O’Regan’s site.
