Though his 18-year-old patient Ida Bauer was “in the first bloom of youth,” Sigmund Freud wrote in 1905, she had come to him suffering from coughing fits and episodes of speechlessness. She’d become depressed and withdrawn, even hinting at suicide. During one session, as he tried to help her uncover the source of her sickness, Freud observed Bauer toying with a small handbag. Interpreting the act as an expression of repressed desire, Freud concluded, “No mortal can keep a secret. If his lips are silent, he chatters with his finger-tips; betrayal oozes out of him at every pore.”
Sometimes a handbag is just a handbag, but modern research does support the idea that secrecy can be a source of mental and physical distress. Keeping a secret, as the idiom suggests, requires constant effort. In one recent study, subjects asked to conceal their sexual orientation in an interview performed worse on a spatial-ability task, reacted more rudely to criticism, and gave up sooner in a test of handgrip endurance . And the bigger the secret, the harder it is to keep. Another study found that subjects asked to recall a meaningful secret perceived hills to be steeper and distances to be longer than those asked to recall a trivial secret. When researchers requested help moving books from their lab, the subjects harboring meaningful secrets lifted fewer stacks .
All of that mental exertion might actually wear a body down: research shows an association between keeping an emotionally charged secret and ailments ranging from the common cold to chronic diseases . Other evidence in favor of disclosure includes multiple studies showing that writing about a traumatic experience can boost the immune system , and the finding that teens who confide in a parent or close friend report fewer physical complaints and less delinquent behavior, loneliness, and depression than those who sit on their secrets .
One reason secret keeping is such hard work is that secrets, like unwanted thoughts, tend to take up more brain space the more one tries not to think about them. But not everyone is equally prone to this self-defeating cycle. Researchers have identified a small class of “repressors,” who experience fewer intrusive thoughts about sensitive information they are suppressing: these clandestine elite may keep their secrets so tightly wrapped that they manage to hide them even from themselves .