Gaslighting is a psychological manipulation tactic in which a person or group makes another person doubt their own perceptions, memories, or understanding of reality. By denying facts, twisting the truth, or presenting false information, the manipulator aims to confuse or undermine the victim, leading them to feel insecure or question their sanity.
The term "gaslighting" comes from the 1938 play "Gas Light," and its 1944 film adaptation, in which a husband manipulates his wife into thinking she is becoming insane by dimming the gas lights in their home and denying that the light changed when she pointed it out.