Columbia Business School professor Michael Slepian and his team asked three groups of 200 volunteers each if they were keeping secrets related to 38 common categories — things like lying, drug use, theft, and sexual infidelity. The researchers found that, on average, each person was keeping 13 secrets. Five of those they never told anyone about.

But there's more. Your secrets might feel like a mental weight, but the study suggested that they're more than that. Slepian told The Atlantic that when a subject thought about their secrets, "they actually acted as if they were burdened by physical weight." This powerful effect occurred even when the subject wasn't hiding a particular secret at that moment.

In addition to feeling weighed down by secretive thoughts, Slepian discovered in a previous study that "people who recalled, were preoccupied with, or suppressed an important secret estimated hills to be steeper, perceived distances to be farther, indicated that physical tasks would require more effort, and were less likely to help others with physical tasks." Weird, huh? Even if you're not actively hiding a secret, thinking about it makes everything more difficult. So, here's the challenge: Just don't think about it.

Slepian's most recent paper notes that our minds are constantly attempting to resolve issues or reach goals we've yet to achieve. But here's the thing: A secret is a goal that can never be accomplished. The Atlantic describes secrets as "Whac-A-Moles in our thoughts — chattering little rodents that won't stay down when you hammer them." Slepian and his team hope to lift the weight of our secrets with their research. After all, 13 secrets is a lot.

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There's nothing juicier than someone else's secret. Peek at the secrets of strangers in "PostSecret: Extraordinary Confessions from Ordinary Lives," compiled by Frank Warren. We handpick reading recommendations we think you may like. If you choose to make a purchase, Curiosity will get a share of the sale.