Mere Exposure Effect

Definition

The mere exposure effect describes the phenomenon that simply encountering a stimulus repeatedly somehow makes one like it more. Perhaps the stimulus is a painting on the wall, a melody on a radio, or a face of a person you pass by every day—somehow all these stimuli tend to “grow on you.” The mere exposure effect is technically defined as an enhancement of attitude toward a novel stimulus as a result of repeated encounters with that stimulus. Interestingly, the mere exposure effect does not require any kind of reward for perceiving the stimulus. All that is required is that the stimulus is merely shown, however briefly or incidentally, to the individual. So, for example, briefly glimpsing a picture or passively listening to a melody is enough for the picture and melody to become preferred over pictures and melodies that one has not seen or heard before. In short, contrary to the adage that familiarity breeds contempt, the mere exposure effect suggests just the opposite: Becoming familiar with a novel stimulus engenders liking for the stimulus.

Background

The mere exposure effect was first systematically examined by Robert Zajonc, who reported his findings in the influential 1968 article “Attitudinal Effects of Mere Exposure.” He presented two kinds of evidence in support of the mere exposure effect. The first kind of evidence was correlational and established a relationship between the frequency of occurrence of certain stimuli and their evaluative meaning. For example, Zajonc reported that words with positive rather than negative meanings have a higher frequency of usage in literature, magazines, and other publications. Thus, the word pretty is used more frequently than ugly (1,195 vs. 178), on is more frequent than off (30,224 vs. 3,644), and first is more frequent than last (5,154 vs. 3,517). Similar findings have also been obtained with numbers, letters, and other apparently neutral stimuli. However, this evidence is correlational, so it is impossible to say if stimulus frequency is the cause of positive meaning or if positive meaning causes the stimulus to be used more frequently. To alleviate concerns associated with the correlational evidence, Zajonc also presented experimental evidence. For [Page 557]example, he performed an experiment and showed that nonsensical words as well as yearbook pictures of faces are rated more favorably after they have been merely exposed to participants. Since then, researchers have experimentally documented the mere exposure effect using a wide variety of stimuli, including simple and complex line drawings and paintings, simple and complex tonal sequences and musical pieces, geometRic figures, foods, odors, and photographs of people. Interestingly, the participants in those experiments included college students, amnesic patients, rats, and even newborn chicks, suggesting that the mere exposure effect reflects a fairly fundamental aspect of psychological functioning.

Conditions Affecting Strength

During this research, scientists have discovered several conditions that modify the strength of the mere exposure effect. Thus, the mere exposure effect is stronger when exposure durations are brief. In fact, the mere exposure effect is sometimes stronger with subliminal rather than supraliminal presentations. The mere exposure effect is also stronger when the repetition scheme is heterogeneous (i.e., with the exposures of a stimulus being interspersed with the presentations of other stimuli) rather than homogeneous (i.e., with all the exposures being of the same stimulus). Furthermore, the magnitude of the mere exposure effect reaches a peak after 10 to 20 stimulus exposures and thereafter levels off. Finally, stronger mere exposure effects are elicited by more complex stimuli and when the experimental situation is set up such that boredom is minimized. In fact, boredom and saturation can sometimes reverse the generally positive effect of mere exposure—a phenomenon certainly experienced by the reader when a massively repeated advertising jingle becomes simply annoying. Some reversals of the mere exposure effect have also been reported with stimuli that are initially negative, though it is unclear whether the increased negativity is due to exposure per se or rather to the unpleasantness that comes from repeated induction of negative affect.

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