Why do people remember things that never happened?

A false memory is a recollection of something that did not happen or is not true. It can be a distorted version of a real memory or an entirely invented one. It is not the same as forgetting or lying, because the person is not trying to deceive anyone. Researchers describe it as an error in how memory is built, stored or retrieved. Memory is not a fixed recording. It is dynamic, often a blend of the original event and later information, and it can change in small ways almost every time something is recalled. Scientists are not certain exactly what causes false memories, but several contributing factors are well described. [1] [2] [3]

According to UChicago's Wilma Bainbridge, the brain does not save everything it sees and uses efficient shortcuts. Asked to recall a living room, a person may add a coffee table or lamp that fit the idea of a living room but were not there. Psychologists have studied this since the 1970s, often with the Deese-Roediger-McDermott procedure. Participants study a list of related words such as dream, bed, awake and rest, and many later recall the word sleep, which was never listed. UChicago's David Gallo describes this as the mind activating its own misinformation. [1]

Misinformation and suggestion can add material to a memory, and existing knowledge or other memories can interfere with a new one. Repetition matters too. The illusory truth effect is the finding that a statement repeated often can start to feel true even when it is not. [4] [1]

Imagination can also leave traces. In experiments described by psychologist Ayanna Thomas, volunteers repeatedly imagined actions such as bouncing a ball or kissing a magnifying glass. Two weeks later, the more often they had imagined an action, the more likely they were to say they had actually done it. Plausible actions were more easily mistaken for real ones than bizarre ones, though errors occurred with both. Thomas also notes that partners who repeatedly reconstruct shared events can absorb details the other person experienced, and become more confident with each retelling. [5]

The Source Monitoring Framework, widely used in discussions of false memories, proposes that the feeling of remembering is a judgment about a current mental experience. People weigh qualities such as perceptual detail, context, emotion and familiarity to decide whether something was perceived, imagined or dreamed. Because these qualities overlap between sources, mistakes happen, for example when a vivid imagining is taken for a past perception. Checks such as testing plausibility or seeking corroboration can create doubt and correct some errors. [6]

Age, stress, lack of sleep, and drug and alcohol use can raise the likelihood of false memories. There are exceptions: more false memories with age is not inevitable, and one source reports that THC can reduce them by making close associations harder to form. [1]