Behavioral clues must be interpreted in the social and psychological context of a specific situation. Often, deceivers fail because they have not planned or rehearsed their story well enough, or because they cannot conceal emotions or falsely portray them. People may experience guilt about the content of the lie, the act of lying itself, or both. Psychopaths, in particular, fail to experience any guilt. According to circumstance, people usually experience less guilt about deceiving those whom they perceive as wrongdoers. For example, a disgruntled employee may feel entitled to steal company goods. Common mistakes in detecting deception are: idiosyncracy error, the failure to take into account individual expressive differences; and othello error or the failure to consider the stress that a truthful person may feel. Lying checklist, table, 42 references.