Would you trust a memory if it felt as real as all your others? And other people confirmed they remember it, too? What if the memory turned out to be false?

This scenario, which might sound like something out of the Twilight Zone, was named the ‘Mandela effect by the self-described ‘paranormal consultant’ Fiona Broome after she discovered that other people shared her (false) memory of South African civil rights leader Nelson Mandela dying in prison in the 1980s. Is a shared false memory really due to a ‘glitch in the Matrix,’ or is there some other explanation for what could be happening?

Broome attributes the disparity to the many-worlds or ‘multiverse’ interpretation of quantum mechanics. When not directly observed, electrons and other subatomic particles diffract like waves, only to behave like particles when a measurement is made. Essentially, it’s as if these particles exist in multiple places simultaneously until directly observed. Nobel laureate physicist Erwin Schrödinger famously characterized this strange concept with the ‘Schrödinger’s cat thought experiment. If a cat were placed in a box with a radioactive decay detector rigged to break a flask of poison when activated, a decaying particle existing as a wave would yield two simultaneous macroscale realities — one where the cat is alive and one where the cat is dead. Although, upon observation, one would only see the cat as either dead or alive, some quantum physicists such as the late Hugh Everett III — originator of the many-worlds interpretation — have speculated that both realities exist … but in separate, parallel universes.

Perhaps both realities exist… but in separate, parallel universes.

It’s important to keep in mind that the many-worlds interpretation was developed to explain the results of physics experiments and not the Mandela effect. Nonetheless, Broome believes that her shared memory isn’t actually false, and that she and others who remember a different past were actually in a parallel reality with a different timeline that somehow got crossed with our current one. More recently people, on Reddit and other websites have identified other instances of the Mandela effect, including shared memories that the children’s book series ‘The Berenstain Bears’ used to be spelled ‘Berenstein Bears‘ and that there was a movie in the 1990s starring Sinbad as a genie called Shazaam. Regardless of what really happened, there’s no denying that shared false memories exist.

Can neuroscience provide an alternative hypothesis for what’s really going on, without evoking quantum physics?

There are several concepts that can illuminate why something so strange could be a shared experience. First it’s important to remember that a memory is made up of a network of neurons in the brain that store the memory. The physical location of a memory in the brain is often called an ‘engram or ‘memory trace.’ During consolidation, the memory trace is transferred from temporary storage sites mediating initial acquisition, such as the hippocampus for facts and events, to permanent storage sites in the prefrontal cortex.

Prior learning creates a framework for similar memories to be stored in close proximity to each other. This framework is known as a ‘schema. A study earlier in 2016 on semantic memory in humans used functional magnetic resonance imaging (fMRI) to show that similar words are stored in adjacent regions of the brain. Researchers used this data to create a ‘semantic map of language in the human cortex. Another recent study confirmed that shared memory traces are spatially consistent in their organization. This evidence supports the idea that schemas allow learned information to be organized by similar content.

Why do groups of people share false memories?

Although we might think of memories as being strengthened when recalled, the truth is actually more complex. Recalling a memory reactivates the neurons composing the memory trace. This causes the neurons to become labile and able to form new connections, which then become stabile again in a process called ‘reconsolidation. Reconsolidation can reinforce repeated learning over time by strengthening connections and allowing the formation of new associations. However, reconsolidation can also render a memory trace vulnerable to losing its fidelity.

At some point in their education, most Americans learn that Alexander Hamilton was a founding father but not a U.S. president. However, when a study on false memory investigated who most Americans identify as U.S. presidents, the subjects were more likely to incorrectly name Hamilton as a president than several actual former presidents. This is likely because neurons encoding information about Hamilton were frequently activated at the same time as neurons encoding information about former presidents. Because neurons that “fire together wire together,” gradually a connection between “past presidents” and “Alexander Hamilton” could become strong enough that you would incorrectly remember Hamilton as a former president himself.

The above study could also help explain why groups of people share false memories. For example, take the mystery of Shazaam. In the 1990’s there was a kids movie called Kazaam starring Shaquille O’Neal as a genie. Many people also falsely remember that there was another film, perhaps a rip-off of Kazaam, called Shazaam, that starred the comedian Sinbad as a genie. Although Shazaam never really existed, there are hundreds of people online who claim to remember it.

There are probably several main reasons for the Mandela effect. The first is that a large number of general associations increase the probability that a false memory could emerge. Twin films with similar concepts being released at around the same time were common in the ’90s. Sinbad released a different movie in the same year as Kazaam called First Kid, which was a comedy where he helped a kid accomplish his goals. He also released a movie called Houseguest which had a cover image of his head coming out of a mailbox, perhaps abstractly resembling a genie emerging from a lamp. Sinbad is an Arabic name, and the story of “Sinbad the Sailor” features encounters with genies. Sinbad’s bald head and goatee resemble a typical genie portrayed in the media. Sinbad also dressed up like a genie for a movie marathon he hosted in the 90’s, which almost certainly contributed to the “memory” of Sinbad playing a genie.

Unlike lying, confabulation is not intended to deceive and the person confabulating fully believes that the “remembered” details are real.

Besides similar associations laying the groundwork for a false memory to form, the other main factors in this instance are “confabulation” and “suggestibility.” The Redditor EpicJourneyMan recounts an extremely detailed account of Shazaam from when he was working in a video store in the 1990s. In his post he describes buying two copies of the movie and having to watch it several times to verify that it was damaged after renters complained. He then proceeds to describe the movie plot in great detail. If Shazaam never existed, how does he have such a detailed memory of the movie?

This is most likely an instance of confabulation, or the brain’s attempt to fill in missing memory gaps by adding fabricated facts and experiences. Unlike lying, confabulation is not intended to deceive and the person confabulating fully believes that the ‘remembered’ details are real. Confabulation is associated with a wide array of neurological disorders, including stroke, brain injury, Alzheimer’s, Korsakoff’s Syndrome, epilepsy, and schizophrenia, but it can also happen in healthy subjects (as anyone with a memory of ‘President Hamilton’ can attest). Instances of confabulation in healthy people increase with age and are thought to be due to age-related changes to the medial temporal lobe, including the hippocampus, and the prefrontal cortex. These brain regions are important for memory encoding and retrieval, and fMRI studies over the past decade suggest that decreased functioning in these regions underlies false memory. It has also been observed that confabulation most often emerges from memories of events that happened repeatedly to create a false memory of a specific instance in a unique spatio-temporal context. In other words, someone who regularly ordered kids videos and watched them to find damaged tape is more likely to confabulate a specific memory of a time when this occurred.

A third phenomenon that could explain the viral popularity of the Mandela effect is suggestibility, the tendency to believe what others suggest to be true. When misinformation is introduced it can actually compromise the fidelity of an existing memory. This is exactly why in a court of law an attorney can object to ‘leading questions’ that suggest a specific answer. In other words, the leading question “Do you remember the 1990s film Shazaam that starred Sinbad as a genie?” not only suggests that such a film actually exists, but could even incept a false memory of having viewed it.

Although it may be tempting to believe that the Mandela effect is evidence that parallel realities exist or that our universe is a glitchy simulation, a true scientist must test his or her alternative hypothesis by trying to disprove it. In light of known cognitive phenomena that can give rise to shared false memories, it’s highly unlikely that some of us are actually from an alternative past universe that crossed timelines with the present one. Nonetheless, the Mandela effect is still a fascinating case study in the quirks of human memory. For those who love thinking about how the mind works, it is perhaps even an example of the truth being stranger than fiction.


Written by Caitlin Aamodt.

Images by Kayleen Schreiber.



Chen, J., Leong, Y. C., Honey, C. J., Yong, C. H., Norman, K. A., & Hasson, U. (2017). Shared memories reveal shared structure in neural activity across individuals. Nature Neuroscience, 20(1), 115-125.

Devitt, A. L., & Schacter, D. L. (2016). False memories with age: Neural and cognitive underpinnings. Neuropsychologia, 91, 346-359.

Ghosh, V. E., & Gilboa, A. (2014). What is a memory schema? A historical perspective on current neuroscience literature. Neuropsychologia, 53, 104-114.

Huth, A. G., de Heer, W. A., Griffiths, T. L., Theunissen, F. E., & Gallant, J. L. (2016). Natural speech reveals the semantic maps that tile human cerebral cortex. Nature, 532(7600), 453-458.

Loftus, E. F. (2005). Planting misinformation in the human mind: A 30-year investigation of the malleability of memory. Learning & Memory, 12(4), 361-366.

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Roediger III, H. L., & DeSoto, K. A. (2016). Recognizing the Presidents: Was Alexander Hamilton President?. Psychological science, 27(5), 644-650.

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Serra, M., La Corte, V., Migliaccio, R., Brazzarola, M., Zannoni, I., Pradat-Diehl, P., & Dalla Barba, G. (2014). Confabulators mistake multiplicity for uniqueness. Cortex, 58, 239-247.

Zaragoza, M. S., Belli, R. F., & Payment, K. E. (2007). Misinformation effects and the suggestibility of eyewitness memory. Do justice and let the sky fall: Elizabeth Loftus and her contributions to science, law, and academic freedom, 35-63.

Additional Sources:

EpicJourneyMan (2016) “The Sinbad Genie Movie – complete analysis” Reddit.

Kramer, M. (2013) “The Physics Behind Schrödinger’s Cat Paradox” National Geographic.

Perpetua, M. (2014) “Did You Know There’s A Term For When You’re Totally Positive Something Happened Even Though It Didn’t?” Buzzfeed.

Tait, A. (2016) “The movie that doesn’t exist and the Redditors who think it does” New Statesman.

(2015) “The Berenst(E)ain Bears Conspiracy Theory That Has Convinced the Internet There Are Parallel Universes” Vice.

Caitlin Aamodt

Caitlin Aamodt

Caitlin Aamodt is a Ph.D. Candidate in Neuroscience at UCLA, where she is developing a novel neuroepigenetic therapeutic to treat learned vocal communication deficits using the zebra finch model system in the lab of Stephanie White. Her research interests broadly include behavioral epigenetics, cognitive evolution, and neuropharmacology. In addition to Knowing Neurons her science writing has appeared on the blogs Speaking of Research and What is Epigenetics? In her spare time Caitlin enjoys electronic music, growing plants, practicing yoga, and writing science fiction. She can be found online at caitlinaamodt.wordpress.com.
Caitlin Aamodt

Latest posts by Caitlin Aamodt (see all)

Caitlin Aamodt

View posts by Caitlin Aamodt
Caitlin Aamodt is a Ph.D. Candidate in Neuroscience at UCLA, where she is developing a novel neuroepigenetic therapeutic to treat learned vocal communication deficits using the zebra finch model system in the lab of Stephanie White. Her research interests broadly include behavioral epigenetics, cognitive evolution, and neuropharmacology. In addition to Knowing Neurons her science writing has appeared on the blogs Speaking of Research and What is Epigenetics? In her spare time Caitlin enjoys electronic music, growing plants, practicing yoga, and writing science fiction. She can be found online at caitlinaamodt.wordpress.com.


  1. Great article! I was not aware of this meme prior to reading.

    I only have one issue with “..permanent storage sites in the prefrontal cortex.” This is speculation. It could be that the pFC is part of a brain network for each separate memory. See Fuster for further elaboration on “cognits” as memory networks.

    Perhaps rewording that last sentence to include something about it being a hypothesis? It currently sounds like we know that is how memory works.

    Otherwise solid reasoning throughout- thank you!

    1. Thanks for the comment! In full disclosure I was trained as a neuroepigeneticist, and within that field it is widely accepted that at least some remote memory is stored in the PFC. For example, work from Davis Sweatt’s lab alone has shown that experience-dependent DNA methylation changes in the PFC are required for remote memory formation and maintenance (Miller et al. 2010 Nat. Neuro), that knocking out a demethylating enzyme enhances remote memory (Sultan et al. 2012 J. Neuro), and that knocking down the histone variant H2A.Z in the hippocampus enhances recent memory, whereas knocking it down in the PFC only enhances remote memory- consistent with prior work on molecular changes underlying consolidation (Zovkic et al. 2014 Nature). So in molecular neuroscience, the fact that we can reliably alter remote episodic memory by manipulating transcriptional regulators in the PFC is considered to be very strong evidence for a role for the PFC in remote memory.

      1. I don’t disagree that the pFC is *involved* in memory. To say a memory is stored in the pFC is a very different claim. We haven’t even touch upon the different flavors of memory- long-term, short-term, working memory and its variants: visual, spatial, etc.. To say a memory is stored in any single place sounds like Lashley’s fabled engram. It’s quite a leap to be making. Hence, an unproven hypothesis at best.

        Thank you again for your contributions. I appreciate the outreach!

  2. When I saw the footage of the JFK assassination I was instantly taken aback by the presence of the roll bar behind the front row of seats.
    I had no recollection of ever seeing that before.
    Nobody had prompted me or suggested anything…it was just obviously very different from 30 years of memories.
    I also do not remember seeing 6 people in the car (only 4) and I also recollect different actions by JFK when first hit and a different subsequent reaction of Jackie.

    As for the spellings and logos changes, well not too sure, although things like David Lettermans speech at the Oscars and all the awards given to Sex ‘in’ the City are certainly very suggestive of something strange going on.

    However, the JFK thing was visceral and palpable: I was instantly aware that the footage was different

  3. Or, history was altered and what we call ‘consciousness’ is in fact the spiritual awakening of each person’s spirit that does not firmly reside in this matrix reality, but instead resides more within a spiritual dimension (ie. a heavenly realm) that is organized more around a ‘wave’ (liquid) frequency dimension versus a ‘particle’ (solid) frequency dimension.

    In other words, we recall the true past because we have a set point (our spirit) that resides outside of the matrix we call earth reality.

    It can not be shifted, like ‘reality’ can.
    So it will see the differences in everyday life occurring, without knowing why.
    It can not be ‘reasoned’ with.
    But go ahead and try.

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