Why do people lie? People lie due to various reasons. Some people are so accustomed to lying that they may lie for no apparent reason. As reported by Pamela Meyer, the author of Liespotting, she says an average person hears 10 to 200 lies in a day, though some lies may go undetected. There are many types of lying, which include: lies of commission, lies of omission, and "nothing but the truth" lies. Telling or hearing a lie is something common to many, although some who lie might be suffering from a personality disorder, or something more serious.