It turns out that gaslighting is a form of mental abuse which false information is presented with the intent of making a victim doubt his or her own memory, perception and quite often, their sanity.
This abuse is sometimes called ambient abuse.
The most common example of gaslighting is to switch something around on someone who you know they’re sure to notice, but then deny knowing anything about it, and to explain that they “must be imagining things” when they challenge these changes.
How did this term come about? It is from the 1938 stage play Gas Light (known as Angel Street in the United States), and the 1940 and 1944 film adaptations.
The plot concerns a husband who attempts to convince his wife and others that she is insane by manipulating small elements of their environment, and subsequently insisting that she is mistaken or misremembering when she points out these changes.
The title stems from the dimming of the house’s gas lights which happens when the husband is in the attic while searching there for hidden treasure. The wife accurately notices the dimming lights, but the husband insists she is imagining.