A study released this week shows that when a person is peer pressured, they can form false memories, convincing themselves of different recollections of the past to fit what others insist is true. The study was published in Science this week.

Study subjects watched a movie in groups, then were questioned individually about it afterward. Four days later, subjects were questioned again. In 70 percent of cases, the researchers found, participants changed their recollection of the film to match their groupmates' incorrect memories. This held true even for questions that the subjects had initially felt very strongly that they had answered correctly.

The researchers called these "socially induced memory errors" because they found conclusive evidence that it was the group that caused the change in answers: Participants were hooked up to an MRI while answering questions, and their hippocampus and amygdala lit up when changing their answers after being told the group's memory differed from theirs, but not when a computer told them they were wrong. In other words, peer pressure convinced people they were wrong, as opposed to cold facts.

In half of the socially induced memory errors, the false memory actually replaced the person's initial, true memory.

Mother Jones points out that the results of this study could explain why poll numbers show such high levels of support for statements such as "Obama is a Muslim" and "Obama is not a U.S. citizen" — statements proven to be wrong by evidence, but vocally supported by some groups.