The term is much in the news recently, applied frequently to the political realm. I've looked it up a number of times in the past and decided I would only remember it if I created a blogpost.
Gaslighting is a form of psychological manipulation that 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, it attempts to destabilize the victim and delegitimize the victim's belief.
The term originates in the systematic psychological manipulation of a victim by her husband in the 1938 stage play Gaslight, known as Angel Street in the United States, and the film adaptations released in 1940 and 1944. In the story, a husband attempts to convince his wife and others that she is insane by manipulating small elements of their environment and insisting that she is mistaken, remembering things incorrectly, or delusional when she points out these changes. The original title stems from the dimming of the gas lights in the house that happened when the husband was using the gas lights in the flat above while searching for the jewels belonging to a woman whom he had murdered. The wife correctly notices the dimming lights and discusses it with her husband, but he insists that she merely imagined a change in the level of illumination.
The term "gaslighting" has been used colloquially since the 1960s to describe efforts to manipulate someone's perception of reality...