OpinionApril 8, 20255 min readPeople Likely Aren’t as Susceptible to False Memories as Researchers ThoughtNew studies underscore the difficulty of implanting entirely fictional events in a person’s recollectionBy Bernice Andrews & Chris R. Brewin Francescoch/Getty ImagesHow much can we trust our memories? We know that our mind keeps an imperfect record of the past. We can forget or misremember details with frustrating consequences. Our attention can be diverted in ways that make it all too easy to miss key events.But a particularly disturbing idea suggests that we readily form false memories—that is, we can become convinced we experienced something that never actually occurred. This concept is often used to cast doubt on the reliability of a plaintiff’s testimony in a court case, suggesting it is easy to create false memories of entire events. For example, lawyers representing Harvey Weinstein cited this idea to raise questions about several women’s allegations against him.Recently we had the opportunity to take a closer look at this concept by analyzing data from a study that intended to replicate one of the most iconic experiments on false memories to date.On supporting science journalismIf you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.The experiment was published by American psychologists Elizabeth Loftus and Jacqueline Pickrell in 1995. Decades earlier, Loftus had demonstrated that people’s memories of visual details could be manipulated by posing questions that contained misinformation. She then wanted to see whether it was possible to implant an entire false memory for a childhood event that had never happened. To that end, in the 1995 study, she and Pickrell misled participants into believing that, according to their parents or older sibling, around age five, they had been lost in a shopping mall and then found by an older woman.Over the course of two sessions, the researchers strongly encouraged 24 participants to remember and describe all they could about this experience (which the parents or older sibling denied had actually happened). The experimenters evaluated the participants’ responses and concluded that one quarter of them had been led to remember the suggested fake event either partially or fully. Loftus had previously claimed some therapists could implant false memories of childhood sexual abuse in their clients. Her “lost in the mall” experiment therefore offered evidence that such a thing might be possible. Over the years, other scientists have implanted false memories of events, such as knocking over a punch bowl at a wedding, traveling in a hot air balloon or putting Slime in a teacher’s desk.In a 2017 paper we identified two big questions that have been hanging over these studies. The first is: How confident can we be in the experimenters’ false memory judgments? For example, would the participants themselves agree that they not only believed in the false event on their relative’s say-so but had an actual memory of it? And secondly, what exactly was it that the participants remembered? Could some of those recollections have been true memories? And what does a “partial” false memory consist of? Our new analysis digs into these questions and suggests that the body of research on false memory induction must be treated with caution: it is likely much more difficult to convince someone of a false memory than past work has suggested.In 2023 Irish psychologist Gillian Murphy and her colleagues closely repeated the “lost in the mall” study, following the original methods. They used a larger sample of 123 people and reported that 35 percent of participants had a false memory, 10 percent more than in the original study. When asked, however, less than half (14 percent) of these participants agreed they had a memory of the fake event.Murphy’s team’s data and transcriptions of what participants actually said were made freely available to other researchers, reflecting a move toward greater transparency in psychological research. We were impressed by this open approach to science, which is the only way to establish whether the claims made for memory implantation stand up to the scrutiny of independent researchers. For the first time, it was possible to examine what was really going on.Before reanalyzing their data, we broke the suggested “lost in the mall” story down into its six core elements. These were that the person was around age five, was lost for an extended period, had cried, was found by an older woman, and was reunited with their family and that this event occurred in the specifically suggested shopping location.To our surprise, none of the participants in the replication study remembered all six elements. Those rated as having a full false memory recalled fewer than three of the details on average, while those described as having a partial false memory recalled about one detail. Even more strikingly, 20 percent of those with a full memory and 60 percent of those with a partial memory did not explicitly remember the defining detail of being lost.We also found that half of those judged to have a false memory had actually been lost before or experienced a similarly analogous situation but not in a way suggested by the experimenters. In all cases, these participants described real events that they clearly distinguished from the suggested fake event. One participant said, “My memory is completely different to the other [suggested] memory.” Another said, “I don’t really remember that one.... But like me getting lost in the shop was like a regular occurrence.” Others were so uncertain about the suggested details in the fake story that their testimony would have little value in court. One participant commented, “I don’t even know if I ever did get lost in the shop before so I’m not sure if it's completely constructed or whether it’s the right memory.”Taking everything into account, we estimated that only five participants could reasonably be claimed to have a false memory rather than the 43 that were originally claimed. The participants were clearly very engaged by the study and approached the task of weighing up what, if anything, they remembered about the suggested event in a sophisticated way. Their comments revealed, for example, that they compared the scenario with other episodes of being lost, thinking about who would have been present and considering if the mall was as suggested. Labeling their musings as a false memory does not capture these important aspects of their experience.Our findings raise serious questions about claims made in court that it is easy to implant entire false memories in others. The great majority of these so-called false memories were much more limited, and held with much less conviction, than the claims made about this type of experiment led us to expect. While these questions remain, psychologists should be very cautious about how they present the findings on memory implantation to others. It is easy to overstate the relevance or generalizability of scientific evidence.Nonpsychologists can take comfort in these findings. Though memory is limited and sometimes mistaken, completely false memories are not easy to implant. Most of the time, memory does a good enough job. And while it is valuable to bring critical distance and skepticism when considering the reliability of memory—particularly in legal contexts—we should not be too quick to throw out a person’s testimony simply because it could be imperfect.Are you a scientist who specializes in neuroscience, cognitive science or psychology? And have you read a recent peer-reviewed paper that you would like to write about for Mind Matters? Please send suggestions to Scientific American’s Mind Matters editor Daisy Yuhas at dyuhas@sciam.com.This is an opinion and analysis article, and the views expressed by the author or authors are not necessarily those of Scientific American.