Everyone has secrets. But new research suggests that it is the very act of having them, and being alone with one's thoughts about them, that takes a toll, as opposed to the idea of keeping them from others being the most harmful aspect of secrets. As lead researcher Michael Slepian of Columbia Business School reports in the Journal of Personality and Social Psychology, this new theory of secrecy holds that secrecy is not an activity but a state of being. It's not the murder, as the New Yorker puts it, but "the incessant beating of the telltale heart." To test this, researchers surveyed 1,200 Americans online and 312 picnicking in Central Park in New York about 38 categories of behavior or identity commonly known to be withheld in our culture.
On average, respondents keep secrets in 13 of these categories, and haven't told anyone their secrets in five categories. At the top of the list: extra-relational thoughts, romantic desire while single, and sexual behaviors such as fantasies, porn consumption, etc. Researchers break down their findings at keepingsecrets.org, and note that when people are alone, they think about their secrets twice as often as when they're actively withholding them in conversation. What surprised the researchers, per Scientific American, is that this active concealment didn't impact personal well-being, but the more often a person considered his secret while alone, the bigger a toll it took in terms of things like stress, depression, and anxiety. (The Dutch king kept a secret for 21 years.)