An error of overgeneralization that occurs when one generalises from what one knows about a person at one moment of time to a permanent characterisation of that person. For example: "he is an unpleasant person" of someone that one has just met. It can also relate to oneself, e.g. "I am unlovable." Trait theories of personality systematically commit this error and imply to people that they cannot change. The bistability suggested by reversal theory suggests that chronotyping involves an oversimplification.