When it comes to deciding whether someone is sharing a real or false memory about committing a crime, our odds are about as good as a coin toss.
In 2015, experts at University College London found that it is surprisingly easy to convince someone they participated in a crime by implanting a false memory. Now, a follow-up study has demonstrated how believable these false memories can actually become.
“Everyone thinks that they couldn’t be tricked into believing they have done something they never did, and that if someone were telling them about a false memory, they would be able to spot it. But we found that actually, people tend to be quite susceptible to having false memories, and they sound just like real memories,” explained study author Dr. Julia Shaw.
The 2015 study was focused on past emotional experiences among a group of young adults. The researchers enlisted the help of family members, who shared detailed memories of events that affected the participants during adolescence.
The experts used suggestive tactics and leading questions to persuade the young adults that they needed help to recover a repressed memory. The researchers then attempted to convince the participants they had committed a crime, such as theft or assault, when they were young. “We were essentially doing exactly ‘what not to do’ when conducting a police interview,” said Dr. Shaw.
The results showed that most of the participants developed a false memory of committing a crime. The young adults were recorded on video as they recounted each fictitious event, which they now believed had actually taken place. The majority of the individuals later reported that the fake memories felt incredibly real.
For the current investigation, a new group of participants was presented with the videos from 2015. They were asked to decide if the events described by the individuals had ever actually occurred.
The participants could only identify false memories of a crime 53 percent of the time – a level of accuracy that is no better than chance. Even when the participants were explicitly told that some of the videos featured false memories, they were still no better at judging between the real and fake stories. In fact, the participants were just as likely to misinterpret a real memory as being fake.
“Legal professionals and police officers need to realize how easy it is to manipulate someone’s memories. Judges in particular should never assume that they can tell when someone has a false memory, and should consider the entire process to see if there was any risk of contamination of a defendant or witness’ memories,” said Dr. Shaw.
“The findings really highlight how important it is to ensure that criminal proceedings are done right. The questioning process should be evidence-based, to reduce the risk of implanting false memories in people being questioned by the police.”
The study is published in the journal Frontiers in Psychology.