Researchers at the University of Notre Dame found that people who lied often had worse mental-health issues, including stress and anxiety, than those who did not lie. The study looked at 110 people—the majority college students—over 10 weeks.
Half the subjects were told to stop lying for the 10 weeks, while the others received no instructions. Both groups came in each week to fill out questionnaires about their health and relationships and take a lie detector test to determine how many lies they had told in the last seven days. According to USA Today, those people who did not lie that week had fewer physical and mental-health complaints than those who had lied. That held true whether the person had told major lies or small ones.
"In a given week, if they told fewer lies, they also reported their health was better," said lead researcher Anita Kelly, a psychology professor at Notre Dame. "The connection between lying less and improved health, following the people over 10 weeks, was amplified by being in the no-lie group. The connection was even stronger."
The findings were presented at the American Psychological Association's annual convention.