Gaslighting is a form of psychological manipulation in which a person seeks to sow seeds of doubt in a targeted individual or in members of a targeted group, making them question their own memory, perception, and sanity. Using persistent denial, misdirection, contradiction, and lying, gaslighting involves attempts to destabilize the victim and delegitimize the victim's belief.
Instances may range from the denial by an abuser that previous abusive incidents ever occurred to the staging of bizarre events by the abuser with the intention of disorienting the victim. The term originated from the 1938 Patrick Hamilton play Gaslight and its 1940 and 1944 film adaptations, in which the gas-fueled lights in a character's home are dimmed when he turns the attic lights brighter while he searches the attic at night. He convinces his wife that she is imagining the change. The term has been used in clinical and research literature, as well as in political commentary.