The Mandela effect: why so many people remember the same thing wrong
Pikachu's tail, the Monopoly Man's monocle. The Mandela effect is a false memory that many people share. Here is what experiments say about it.
A quick quiz before we start. Does the Monopoly Man wear a monocle? Does Pikachu’s tail end in a little black tip? If you said yes to either one, you are in very good company. You are also wrong. Neither of them has one.
That feeling of “but I’m sure I saw it” has a name: the Mandela effect.
Where the name comes from
Nelson Mandela walked out of prison on 11 February 1990, became South Africa’s first democratically elected president in 1994, and died at his home in Johannesburg on 5 December 2013. But paranormal researcher Fiona Broome remembered him dying in prison back in the 1980s, and she said other people remembered the very same thing. She called it the Mandela effect.
Online, the name spread to any case where lots of people share the same, very specific false memory of a name, an event or a picture. Broome and others took these shared slips as “evidence” of alternate dimensions. Psychologists see something different: a puzzle about how memory works.
Putting famous pictures to the test
In 2022 Deepasri Prasad and Wilma Bainbridge at the University of Chicago turned the Mandela effect into an experiment. They showed 100 adults 40 famous characters, logos and symbols. Each one came in three versions: the real design and two slightly altered copies. The task was simply to pick the real one.
For most icons, people usually chose correctly. But for seven of them (C-3PO, Curious George, the Fruit of the Loom logo, the Monopoly Man, Pikachu, the Volkswagen logo and Waldo), people chose one particular wrong version more often than the real design. They felt familiar with these characters and were confident in their answers. And the mistakes matched: people who got them wrong tended to pick the same wrong picture.
The made-up details are oddly specific. People pictured a monocle on the Monopoly Man, a black-tipped tail on Pikachu, a tail on Curious George (he doesn’t have one), a cornucopia behind the fruit in the Fruit of the Loom logo, and an all-gold C-3PO, who in fact has one silver leg.
The team then tested simple explanations, and none of them explained it on its own:
- Not looking carefully? In a second experiment, people studied the real pictures while a mouse-tracking tool recorded where they looked. They inspected these icons no differently from others. Even so, many picked the made-up version a few minutes later, and those who chose wrong often said they remembered seeing the detail that was never there.
- Seeing the wrong version a lot? The researchers collected the top 100 Google Images results for each icon. For some, such as C-3PO, whose legs are often out of the frame, the false version does turn up. But Pikachu and the Monopoly Man hardly ever appeared in their false form.
- Only fooled by multiple choice? When people drew the icons from memory with no options to choose from, many drew the false details on their own.
Their conclusion was honest. There may be no single cause. Some slips may come from expectations (a rich old gentleman “should” have a monocle), some from occasionally seeing a variant, and some from something about the pictures themselves that scientists don’t understand yet.
Familiar isn’t the same as accurate
This isn’t new. In 1979 Raymond Nickerson and Marilyn Adams found that people remember the details of the US penny remarkably poorly, even though it is one of the most common objects around. Seeing something often doesn’t mean we store every detail of it.
A word that was never on the list
You can watch a false memory form in a simple lab game. In 1995 Henry Roediger and Kathleen McDermott gave people lists of 12 words, such as bed, rest, awake and so on, all connected to one word that was never on the list: sleep. When people recalled a list right away, they included the missing word 40% of the time, and later they recognized it with high confidence. In a second experiment with more lists, false recall rose to 55%.
Our memory quietly filled in the word that “should” have been there.
Why do false memories happen?
A memory is not a video that plays back the same way every time. Psychologists Daniel Schacter and Donna Rose Addis describe memory for events as constructive: each time we remember, we rebuild the scene from pieces, and that makes it prone to errors and illusions.
They argue this has an upside. The same system that rebuilds the past lets us imagine the future by pulling out bits of earlier experiences and recombining them. In a 2007 brain scanning study, Addis, Wong and Schacter found that building a memory of a past event and building an imagined future event both engaged the left hippocampus, a seahorse-shaped region deep in the brain. Much of it was removed in patient H.M., who could then no longer form new memories. A memory that can remix itself is very useful. Every so often, though, the remix is what we remember.
A false memory made on purpose, in mice
In 2013 a team led by Susumu Tonegawa showed how direct this can be. In mice, they tagged the hippocampal cells that became active in one box with a light-sensitive protein, using optogenetics. Later, in a different box, the mice received a foot shock while light switched those first-box cells back on. When the mice returned to the first box, where nothing bad had ever happened, they froze in fear. They were acting on a memory of something that never happened there.
So, is the Mandela effect real?
As a memory effect, yes. Experiments show that many people can share the same specific false memory and feel confident about it. None of this calls for parallel universes. It is what a rebuilding, gap-filling memory sometimes does. Why a few particular pictures trip up so many of us remains an open question.
In short
The Mandela effect is a shared false memory. It shows up for certain famous pictures even when people have mostly seen the real version. Memory rebuilds instead of replaying, and the hippocampus that helps us remember also helps us imagine. So the next time you are sure about a monocle, take a second look.
Sources
- The Visual Mandela Effect as Evidence for Shared and Specific False Memories Across People. Prasad D, Bainbridge WA. Psychological Science 33, 1971–1988 (2022). Experiment details from the accepted manuscript on PsyArXiv, doi:10.31234/osf.io/nzh3s
- Biography of Nelson Mandela. Nelson Mandela Foundation
- Long-term memory for a common object. Nickerson RS, Adams MJ. Cognitive Psychology 11, 287–307 (1979)
- Creating false memories: remembering words not presented in lists. Roediger HL, McDermott KB. Journal of Experimental Psychology: Learning, Memory, and Cognition 21, 803–814 (1995)
- The cognitive neuroscience of constructive memory: remembering the past and imagining the future. Schacter DL, Addis DR. Philosophical Transactions of the Royal Society B 362, 773–786 (2007)
- Remembering the past and imagining the future: common and distinct neural substrates during event construction and elaboration. Addis DR, Wong AT, Schacter DL. Neuropsychologia 45, 1363–1377 (2007)
- Creating a false memory in the hippocampus. Ramirez S, Liu X, Lin PA, et al., Tonegawa S. Science 341, 387–391 (2013)
