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Study: Telling the Truth May Actually Improve Your Health

Want to feel better? Here's a simple prescription.


I gave a presentation at the recent national convention of the American Psychological Association here in Washington, D.C., on the results of the newest study from my Science of Honesty project, with co-author Lijuan Wang, who is also a professor at the University of Notre Dame.

The design of our study, which we just finished last week, was simple: 72 healthy adults (with an average age of 41) were recruited through newspapers in the South Bend, Indiana community. They were randomly assigned to two groups: a Sincerity group, and a Control group. Both groups came to my laboratory each week for 5 weeks to complete polygraph tests and anonymous health measures.

Members of the Sincerity group—but not of the Control group—was also told:

“Throughout every day of the next 5 weeks, you must speak honestly, truthfully, and sincerely—not only about the big things, but also about the small things, such as why you were late. You must always mean what you say in situations where your statements are to be taken seriously, as opposed to when joking or obviously exaggerating. While you certainly can choose not to answer questions, you must always mean what you say.”

What was so amazing is that in the fifth and final week of the study, the Sincerity group reported significantly fewer physical health complaints than the Control group. Specifically, they had experienced an average of 7 fewer symptoms such as sore throats, headaches, nausea that week. Because the only difference between the two groups was the sincerity instructions, we can conclude that these instructions actually caused the health benefit.

Since the fall, I too have been following these instructions. Normally I get 8 hours of sleep and have five-to-seven colds in a winter. Now, even with only 3 hours of sleep, I have been sick zero times since the fall. Thus, I could not hold off on telling you about the results. The impact is so compelling that I urge you to try it.

It might not be easy to “always mean what you say." You might find that you have to go back and correct some of the things that pop out of your mouth. But don’t let that discourage you. Being sincere is a process and you will get there with practice. And when you do, you will see that you are becoming more humble, more open to learning, and less sensitive to rejection. Being sincere brings you closer to the decent people you know, pushes away the naysayers, and allows you to feel a certain hopefulness about the world. To the extent that you experience these, I believe you too will have profound health benefits.

You are more than welcome to post your progress in the comments here. I would love to read them; and I believe it will help inspire other readers to stay the course with you.


This post stems from Anita Kelly’s Science of Honesty project, which was made possible through the support of a grant from the John Templeton Foundation. The opinions expressed in this post are those of the author and do not necessarily reflect the views of the John Templeton Foundation.

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