Can Hypnosis Create False Memories?

Yes, when hypnosis is used to dig up the past. The risk comes from two things working together: memory is rebuilt every time we recall it, and suggestion can change what gets rebuilt. Hypnosis aimed at a present-day goal, such as a fear or a habit, is a different use and does not involve retrieving memories at all.

Why is memory so easy to change?

We tend to imagine memory as a recording. The research of psychologist Elizabeth Loftus shows why it is not. In her 1974 study with John Palmer, as summarized by Simply Psychology, 45 students watched films of traffic accidents and then estimated the cars’ speed. The only thing that changed between groups was one verb in the question. When the cars “contacted” each other, the average estimate was 31.8 mph. When they “hit” each other, it was 34 mph. When they “smashed” into each other, it rose to about 40.8 mph.

In the paper’s own words, quoted in her Wikipedia biography, the results are consistent with the view that questions asked after an event “can cause a reconstruction in one’s memory of that event.” Nobody in that study was hypnotized. A single word was enough to shift what people believed they had seen.

Can a whole event be planted?

The lost-in-the-mall study, published by Loftus and Jacqueline Pickrell in 1995, tested exactly that. The 24 participants read four short accounts of childhood events based on information from an older relative; one of them, being lost in a shopping mall as a young child, was invented. About 25 percent reported remembering the false event. Their false memories were usually less clear than their true ones and described in fewer words, and at the end five of the 24 picked a true event as the invented one.

The study has critics. In 1999 the psychologists Lynn Crook and Martha Dean questioned its ethics and argued that the results do not generalize to real-life memories of trauma; Loftus replied, pointing to what she called “exaggerations, omissions and errors” in their account. A 2019 paper by Crook and Linda McEwen re-examined the data and argued that the experiences of two of the subjects did not qualify as the “existence proof” Loftus called the study. The debate is real, and it is worth knowing both sides before treating any single study as settled.

Where does hypnosis come in?

Hypnosis is not the only way to distort a memory, but it brings the ingredients together. A 2024 review of the neuroscience of hypnosis describes it as an interaction in which the participant responds to verbal suggestions for imaginative experiences, including distortions of perception and memory. Add a practitioner who is asking about the past, and the conditions for a reconstructed memory are in place. WebMD’s medically reviewed overview of hypnosis risks describes the use of hypnosis to bring back memories as controversial and warns that, in the hands of someone who is not a trained professional, it could create fake memories that further confuse a person’s mental health problems.

The difficulty is that a false memory does not feel false. In the mall study, some participants could not tell the invented event from the real ones even when told one was invented. Confidence in a memory and accuracy of a memory are two different things.

What was the recovered-memory controversy?

In 1991, several high-profile court cases involved people who said they had recovered memories of being molested by their parents. Psychology books of the period instructed women and therapists in methods for recovering “lost” memories of abuse. Loftus argued, drawing on her experiments, that some of these memories could have been created rather than recovered. Her 1994 book, The Myth of Repressed Memory, made that case to a general audience.

Psychologists who work with recovered memories have pushed back on parts of that argument, as the criticism above shows. Two points survive on both sides of the debate: suggestion can change memory, and a memory that surfaces under hypnosis is not, by itself, evidence that the event happened.

How do you protect yourself?

The safeguard is about the goal, not the technique.

• Decline memory recovery. Be wary of anyone who offers to uncover repressed memories, confirm abuse you do not remember, or reveal what “really happened” in your past.
• Keep sessions on present-day aims. Working on how you respond to a trigger, a fear or a habit does not require retrieving the past.
• Treat vivid recall with care. If an image or memory comes up during a session, it can be worth exploring with a therapist, but it should not be acted on as established fact.
• Ask about training. WebMD links the false-memory risk to untrained practitioners; ask what training a practitioner has and how they handle memories that surface.

If you already believe a memory recovered in hypnosis is real, a licensed psychologist or psychiatrist is the right person to help you work through it carefully, without either dismissing it or treating it as proof.

This article is general information, not medical or psychological advice; talk with a licensed clinician about your own situation.