Three Reasons Not to Trust Your Memory

Science shows us why taking memories at face value is risky.

By Josefin Dolsten, published May 7, 2016 - last reviewed on July 4, 2016

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We are often unaware of just how flawed—or even false—our recollections can be. Psychologist Julia Shaw, author of The Memory Illusion, uncovers new reasons to exercise caution when consulting your mental pictures of the past.

People can recall events that never happened.

In an experiment reported in Psychological Science, Shaw and colleagues persuaded college students that they were guilty of an imaginary crime. In addition to recounting a true, emotional event from each student's life—based on accounts from parents or caregivers—the researchers hinted at a theft or minor assault supposedly committed years earlier. After a series of interviews and visualization exercises, 70 percent of students relayed details from the incident ("remembering" throwing a rock at someone, for example). Social suggestion can produce similar results. "Your family might say that they took you to Disneyland as a child, when it was actually your sister," Shaw says. Envisioning the details of the trip can lead you to think you are remembering them.

All memories are inaccurate to some degree.

Imperfect memory-making processes, from selective perception to faults in how the brain stores memories, cause us to remember the past with less than total accuracy. "Most of our memories are probably just a little bit false, like remembering that our friend wore a blue sweater rather than a red one to a coffee date," Shaw says. Emotion and distraction can also cloud our memory: When we are threatened or our attention is otherwise diverted, the person or object that has captured our attention can blind us to peripheral details.

Identifying false memories may be next to impossible.

New research suggests that "if we watch videos of people recalling true and false memories, we cannot reliably tell the difference," Shaw says. "We may actually be better off flipping a coin." How can we know whether our memories are inaccurate or imaginary when other people are unable to correct us? Comparing our recollections with those of others has its flaws, since memory corruption affects everyone. Moreover, false memories are easy to take at face value if we recall them in considerable detail: "We often assume that there is no way that a complex description could be fictitious." The only truly reliable form of corroboration, Shaw says, is hard evidence, like photos, emails, and social media posts that document past events.