Simply asking people whether they experienced an event can trick them into later believing that it did occur, according to a neat little study just out: Susceptibility to long-term misinformation effect outside of the laboratoryPsychology experiments have shown that it is surprisingly easy to plant false memories in people's minds. They will sincerely swear that they remember something that in fact never happened.
Many people, especially women, tell fantastic stories of abuse or domestic violence from years in the past. There stories seem unlikely, but it also seems unlikely that they are deliberately lying.
Psychologists Miriam Lommen and colleagues studied 249 Dutch soldiers were deployed for a four month tour of duty in Afghanistan. As part of a study into PTSD, they were given an interview at the end of the deployment asking them about their exposure to various stressful events that had occurred. However, one of the things discussed was made up – a missile attack on their base on New Year’s Eve.So if you ask women if they are victims of domestic violence, then maybe 26% of them will conjure up false memories of it.At the post-test, participants were provided new information about an event that did not take place during their deployment, that is, a (harmless) missile attack at the base on New Year’s Eve.Eight of the soldiers reported remembering this event right there in the interview. The other 241 correctly said they didn’t recall it, but seven months later, when they did a follow-up questionnaire about their experiences in the field, 26% said they did remember the non-existent New Year’s Eve bombardment (this question had been added to an existing PTSD scale.)
We provided a short description of the event including some sensory details (e.g., sound of explosion, sight of gravel after the explosion). After that, participants were asked if they had experienced it…
Susceptibility to the misinformation was correlated with having a lower IQ, and with PTSD symptom severity.
False memory effects like this one have been widely studied, but generally only in laboratory conditions. I like this study because it used a clever design to take memory misinformation into the real world, by neatly piggybacking onto another piece of research.
Also, it’s interesting (and worrying) that the false information was presented in the context of a question, not a statement. It seems that merely being asked about something can, in some cases, lead to memories of having experienced that thing.
Not sure about the correlation with PTSD. Maybe these soldiers were asked about PTSD, and also had false memories leading to the PTSD diagnosis.