Gaslighting is a psychological manipulation tactic where one person seeks to make another doubt their own perceptions, memories, or reality. This often involves denying facts, lying, or presenting false information, leading the victim to feel confused and insecure about their own thoughts. The term originates from the 1938 play and subsequent films titled Gas Light, where a husband manipulates his wife into thinking she is losing her sanity. Gaslighting can occur in various relationships, including romantic partnerships, friendships, and even workplace dynamics, and can have serious emotional and psychological effects on the victim.