Reasons for imposture
Many impostors try to gain financial or social advantages through social engineering or through means of identity theft, but also often for purposes of espionage or undercover law enforcement. Their objective may be one of sexual gratification, giving a false name, false claim of being single or unwed, and/or false age in order to hide adultery, bigamy, or to catfish (e.g. a pedophile pretending to be a youth online).
Those in witness protection, those fleeing abusers or persecution, and criminals evading arrest may also assume a false identity.
Economic migrants may pose as tourists (visitor visas) or as international students (international student visas with a non-accredited university or college). In some countries, such as Canada, students from abroad on educational visas sometimes then present as asylum claimants to obtain residency or citizenship.
Some impostors may do it for pathological reasons, such as having a personality disorder that involves an excessive need for attention and emotional reactions from others (be it praise and/or sympathy), an excessive sense of self-importance or being special, an excessive sense of entitlement, an excessive need to control others, a lack of remorse or emotional empathy, chronic and frequent exaggeration or lying about one’s abilities or life events, and exploitativeness. These psychological conditions may include narcissistic personality disorder (NPD), antisocial personality disorder (psychopathy and sociopathy), Munchausen syndrome (factitious disorder imposed on self) and Munchausen-by-proxy (factitious disorder imposed on another).
According to forensic psychologist Ian Joblin, people who invent extraordinary life stories often do so to overcome feelings of inadequacy. By inventing an identity that embodies qualities admired within their culture, they seek validation, confidence, and influence. Such deceptions usually begin with small exaggerations that expand as they are accepted by others. As the fabricated narrative grows, it evolves to resolve inconsistencies, and the confabulator's insecurity may develop into an inflated sense of power and invulnerability.
People have also posed as others as a hoax or prank, sometimes for amusement, but also for publicity or as part of a protest, sometimes later revealing their true identity.
Many women in history have presented themselves as men in order to advance in typically male-dominated fields. There are many documented cases of this in the military during the American Civil War. However, their purpose was rarely for fraudulent gain. They are listed in the List of wartime cross-dressers.
Spies have often pretended to be people other than they were. One famous case was that of Chevalier d'Eon (1728–1810), a French diplomat who successfully infiltrated the court of Empress Elizabeth of Russia by presenting as a woman.
Historically, when military record-keeping was less accurate than today, some persons—primarily men—falsely claimed to be war veterans to obtain military pensions. Most did not make extravagant claims that would attract attention and possible exposure. In the modern world, falsely posing as a member of the military or exaggerating one's service record is almost always only to gain undeserved respect and admiration.
Scientists and filmmakers may also engage in imposture for the purposes of conducting a social experiment or public education; later revealing the deception to participants and public is a key part of the experiment. For instance, James Randi's Project Alpha; Derren Brown's Messiah, and Fear & Faith; and Vikram Gandhi's Kumaré.
