Tag Archive | "Familiarity"



Cryptomnesia occurs when a forgotten memory returns without its being recognised as such by the subject, who believes it is something new and original. It is a memory bias whereby a person may falsely recall generating a thought, an idea, a song, or a joke, not deliberately engaging in plagiarism but rather experiencing a memory as if it were a new inspiration. Sentences in scientific papers that are identical to sentences from some of the references used to write the paper often stem from cryptomnesia.

In the first empirical study of cryptomnesia, people in a group took turns generating category examples (e.g., kinds of birds: parrot, canary, etc.). They were later asked to create new exemplars in the same categories that were not previously produced, and also to recall which words they had personally generated. People inadvertently plagiarized about 3–9% of the time either by regenerating another person’s thought or falsely recalling someone’s thought as their own. Similar effects have been replicated using other tasks such as word search puzzles and in brainstorming sessions.

Research has distinguished between two kinds of cryptomnesia, though they are often studied together. The distinction between these two types of plagiarism is in the underlying memory bias responsible—specifically, is it the thought that is forgotten, or the thinker? The first type of bias is one of familiarity. The plagiarizer regenerates an idea that was presented earlier, but believes the idea to be an original creation. The idea that is reproduced could be another’s idea, or one’s own from a previous time. B. F. Skinner describes his own experience of self-plagiarism;

“One of the most disheartening experiences of old age is discovering that a point you just made—so significant, so beautifully expressed—was made by you in something you published long ago.”

The second type of cryptomnesia results from an error of authorship whereby the ideas of others are remembered as one’s own. In this case, the plagiarizer correctly recognizes that the idea is from an earlier time, but falsely remembers having been the origin for the idea. Various terms have been coined to distinguish these two forms of plagiarism — occurrence forgetting vs. source forgetting and generation errors vs. recognition errors. The two types of cryptomnesia appear to be independent: no relationship has been found between error rates and the two types are precipitated by different causes.

Cryptomnesia is more likely to occur when the ability to properly monitor sources is impaired. For example, people are more likely to falsely claim ideas as their own when they were under high cognitive load at the time they first considered the idea. Plagiarism increases when people are away from the original source of the idea, and decreases when participants are specifically instructed to pay attention to the origin of their ideas. False claims are also more prevalent for ideas originally suggested by persons of the same sex, presumably because the perceptual similarity of the self to a same-sex person exacerbates source confusion. In other studies it has been found that the timing of the idea is also important: if another person produces an idea immediately before the self produces an idea, the other’s idea is more likely to be claimed as one’s own, ostensibly because the person is too busy preparing for their own turn to properly monitor source information.

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Mere exposure effect

The exposure effect is a psychological phenomenon by which people tend to prefer things because they are familiar with them. In social psychology, this effect is sometimes called the familiarity principle. In studies of interpersonal attraction, the more often a person is seen by someone, the more pleasing and likeable that person appears to be.


In the 1960s, a series of laboratory experiments by Robert Zajonc demonstrated that simply exposing subjects to an unfamiliar stimulus led them to rate it more positively than other, similar stimuli which had not been presented. Researchers have used words, Chinese characters, paintings, pictures of faces, geometric figures, and auditory stimuli in these experiments. In one variation, subjects were shown an image on a tachistoscope for a very brief duration that could not be perceived consciously. This subliminal exposure produced the same effect, though it is important to note that subliminal effects are generally weak and unlikely to occur without controlled laboratory conditions. According to Zajonc, the exposure effect is capable of taking place without conscious cognition, and that “preferences need no inferences.”

A meta-analysis of 208 experiments found that the exposure effect is robust and reliable, with an effect size of r=0.26. This analysis found that the effect is strongest when unfamiliar stimuli are presented briefly. Mere exposure typically reaches its maximum effect within 10-20 presentations, and some studies even show that liking may decline after a longer series of exposures. For example, people generally like a song more after they have heard it a few times, but many repetitions can reduce this preference. A delay between exposure and the measurement of liking actually tends to increase the strength of the effect. Curiously, the effect is weaker on children, and for drawings and paintings as compared to other types of stimuli. One social psychology experiment showed that exposure to people we initially dislike makes us dislike them even more.


Although the exposure effect appears to have a natural place in advertising, research has been mixed as to how effective it is at enhancing consumer attitudes toward particular companies and products. According to one study, higher levels of media exposure are associated with lower reputations for companies, even when the exposure is mostly positive. A subsequent review of the research concluded that exposure leads to ambivalence because it brings about a large number of associations, which tend to be both favorable and unfavorable. Exposure is most likely to be helpful when a company or product is new and unfamiliar to consumers.

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