Keeping secrets can lead to stress, sleep loss, and other unhealthy consequences, new research suggests. Psychologists at Columbia Business School asked 1,200 Americans online, and 312 in person, about their secrets. Participants admitted to keeping an average of 13 things to themselves – such as thoughts of infidelity, sexual fantasies, and betrayals of trust including five about which they’d never told anyone. But the researchers found that they spent twice as much time dwelling on their secrets in private then they did actively concealing them from others – and that the more often people ruminated on their secrets, the less healthy they said they were. “Secrets exert a gravitational pull on our attention,” study co-author Malia Mason tells MedicalDaily.com. “It’s the cyclical revisiting of our mistakes that explains the harmful effects that secrets can have on our well-being and relationship satisfaction.”