One of my favorite movies of all time is Gaslight (1944) starring Ingrid Bergman and Charles Boyer.
Based on a 1938 play by Patrick Hamilton and directed by George Cukor, Gaslight combines an extraordinarily talented cast with an edge-of-your-seat plot. Not only does this superb psychological thriller continue to hold its entertainment value after 72 years, it has given the language a psychological term that has really been getting a workout in 2016.
The play is set some time in the 1890s or later and takes its title from a plot device.
A villainous husband is secretly searching the attic of his own house. When he turns on the gas jets in the attic, the gaslights in the house below dim. His wife notices, but he tells her she is imagining things. As time goes on, he creates other situations to persuade her that she can’t trust her own perceptions. Their creepy maid reinforces the wife’s misgivings by siding with the husband.
From the context of the story, the verb to gaslight has come to mean “to manipulate a person by psychological means into questioning his or her own sanity.” The noun is gaslighting.
The most frequent use of the term seen lately is in a political context. A political figure or spokesperson for a political organization makes a statement that is demonstrably untrue but insists that is true.
Fortunately for the wife in Gaslight, a sane outsider intervenes, disrupts the false narrative, and the crazy husband is carted away.
Unchallenged, he might have succeeded, especially since he had an ally in the house.