Psst…Keeping a secret can be a real physical burden

Feeling burdened by a secret? Does being sworn to secrecy make you feel sluggish and tired? That physical anguish isn't all in your head.

A new study, published in the Journal of Experimental Psychology, found that secrets really do "weigh people down," and not just mentally.

Michael Slepian, a researcher at Tufts University, found that in four different tests, keeping a secret proved to have real -- and perceived -- physical effects.

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In the first test, Slepian and his collegues found 40 people were told to recall a secret. They were then each asked to estimate the steepness of a hill. Those harbouring a meaningful personal secret believed the hill was steeper than those who merely recalled small secrets.

In another test, the researchers found 40 people who admitted to recent infidelity. The participants first rated their guilt over the matter, then asked them to rate the energy and effort required to perform common tasks, such as carrying groceries upstairs, helping someone move, or walking the dog. The people who were more bothered by their secret rated the tasks as using more energy.

"The more burdensome their secrets were, the more participants perceived everyday behaviours as if they were carrying a physical burden," the authors write in the study.

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The study's conclusion? "The more burdensome the secret and the more thought devoted to it, the more perception and action were influenced in a manner similar to carrying physical weight," the authors write.

The brain doesn't like secrets. Neuroscientist David Eagleman told NPR that harbouring a secret increases levels of stress hormones in the body. "You have competing populations in the brain — one part that wants to tell something and one part that doesn't....And the way that that battle tips, determines your behaviour," he says.

Writing down secrets in a journal can decrease those stress hormones. So even if you've sworn to keep your mouth shut, find relief by opening a notebook.

Slepian's secrecy study isn't the first to investigate the physical consequences of secret-keeping. In 2006, Anita E. Kelly, a psychologist at the University of Notre Dame told the Association for Psychological Science that "secretive people also tend to be sick people."

From a healthy-living standpoint, maybe spilling the beans is a good thing.

Can you keep secrets? If so, for how long?