Lead author Anita E. Kelly, professor of psychology at the University of Notre Dame, and Lijuan Wang, also of Notre Dame, conducted the honesty experiment for 10 weeks with a sample of 110 people, of whom 34 percent were adults in the community and 66 percent were college students. They ranged in age from 18 to 71 years, with an average age of 31.
Half the participants were instructed to stop telling major and minor lies for the 10 weeks. The other half served as a control group that received no special instructions about lying. Both groups came to the laboratory each week to complete health and relationship measures and to take a polygraph test assessing the number of major and white lies they had told that week.
As the study continued, the link between fewer lies and improved health were significantly stronger for participants in the no-lie group, the researchers said.
"We found that the participants could purposefully and dramatically reduce their everyday lies, and that in turn was associated with significantly improved health," Kelly said in a statement.
The findings were presented at the American Psychological Association's 120th annual convention in Orlando, Fla., and will be submitted for scientific review and publication later this year, Kelly said.