Psychologists are finding more and more evidence that our memories can be very easily manipulated. From Neuronarrative:
In the first study, researchers wanted to know if they could convince people that they’d committed an act they never did. To accomplish this, they created a computerized multiple choice gambling task for participants to complete, which entailed increasing the winnings from a sum of money as much as possible by answering questions. The money was withdrawn from an online bank based on cues given to participants by the computer program: when they answered questions correctly, they were told to withdraw money from the bank; when they answered incorrectly, they were instructed to deposit money back into the bank. Subjects were videotaped while they completed the task.
Afterwards, participants were asked to sit and discuss the task with a researcher. During the discussion, the researcher said he’d identified “a problem” during the task, and then accused the participant of stealing money from the bank. Some of the participants were told that video evidence showed them taking the money (but they weren’t actually shown the video), while others were shown video “proving” that they took the money. What the participants didn’t know, of course, is that the video had been edited to make it appear as if they did something they had not. Participants were then asked to sign a confession stating that they did in fact take money from the bank when they should have deposited it back.
Participants were given two chances to sign the confession, and by the end of the day all of them did. 87% signed on the first request, and the remaining 13% signed on the second. Interestingly, even participants merely told that the video showed them taking the money eventually complied with the confession.