It doesn’t take long to believe your own lies

We believe the lies we tell are the truth in as little as 45 minutes, according to a new study.

Researchers used electroencephalography (EEG) to monitor the brain activity of younger and older adults while they gave truthful and false answers on questionnaires.

In the study, the older cohort, ages 60–92, were significantly more likely than the 18–24-year-olds to accept as the truth a lie they had told less than an hour earlier.

“Older adults have more difficulty distinguishing between what’s real and not real,” says first author Laura Paige, a former graduate student in the lab of Angela Gutchess, an associate professor of psychology at Brandeis University.

“Once [you’ve] committed to a lie, it’s going to alter whether [you] remember doing something…”

Paige says her findings suggest that telling a falsehood scrambles older people’s memory so they have a harder time recalling what really happened, in effect giving greater credence to the lie.

Related: Can you spot the liar in this group?

“Once they’ve committed to a lie, it’s going to alter whether they remember doing something,” says Paige, who now works for Applied Marketing Science, a market research and consulting firm in Waltham, Massachusetts.

In the study, 42 participants, about half seniors and half millennials, were given a form with 102 questions about what they did the previous day. The form asked them to respond to questions such as “Did you press snooze on your alarm clock?” and “Did you use a fork to eat lunch?”

On half the questions, chosen at random, the researchers told the subjects to lie.

EEG data revealed that lying engaged the brain processes responsible for working memory.

Forty-five minutes later, the respondents answered the same questionnaire. This time, researchers told them to answer all the questions truthfully.

The central research question was: Did the lie stick? When the participants lied on a question the first time, did they remember they had lied or did they now think the lie was the truth?

The results showed that compared to the younger group, older adults were more inclined to believe the lie.

In addition, the EEG data revealed that lying engaged the brain processes responsible for working memory. According to Paige, this finding suggests a lie can embed itself in memory and come to feel as real as the truth.

“Lying alters memory,” she says. “It creates a new memory for something that didn’t happen.”

The research appears in the journal Brain and Cognition.

Source: Lawrence Goodman for Brandeis University

Original Study DOI: 10.1016/j.bandc.2018.10.002

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