Has it ever happened to you that something (e.g. a song) has become more and more appealing to you as you have listened to it more and more? Or even to someone else? This has an explanation according to social psychology; it is the so-called Mere Exposure Effect .

The Effect of Mere Exposure was discovered by Robert Boleslaw Zajonc, an American social psychologist. The effect is that the more we are exposed to something, the more we like it . However, some authors suggest that this only occurs when the initial attitude towards the stimulus or object is favourable.

In this article we will know the origin of this effect, some of the conditions that will influence it and possible causes of its appearance.

The Effect of Mere Exposure

The Effect of Mere Exposure is a psychological phenomenon that consists in the fact that our liking for a certain stimulus or person increases as we are more exposed to it, that is, the more we are exposed, the more we will like it. This effect is typical of social psychology, which sometimes also calls it the “principle of familiarity” .

The effect of mere exposure was initially described by R.B. Zajonc (1968); Zajonc presented his finding, along with others, in a paper devoted to changing attitudes, in which he argued that attitudes are formed by the frequency with which we are exposed to a stimulus.

The effect of Zajonc’s mere exposure facilitated new avenues of research within the experimental psychology of emotion.

The works of R.B. Zajonc

From his work on the Mere Exposure Effect, Zajonc supports the hypothesis that “the mere repeated exposure of a subject to a stimulus is a sufficient condition for the increase of a positive attitude towards this stimulus”. This effect appears even when the stimulating conditions of presentation prevent its conscious identification .

Zajonc’s hypothesis implied a challenge to the theoretical positions of the moment (1960s), and stated that attitudes could be formed simply from the frequency with which a stimulus is presented.

In any case, researchers in social psychology, at that time, already intuited that the more familiar we are with a stimulus, the more likely it is that our attitude towards it will be positive or favourable.

Experimental procedure

In order to study the effect of mere exposure in an experimental way, the subjects were exposed to our affective stimuli for very short times; after this presentation, the subject was shown various new stimuli , of similar characteristics, among which the stimuli exposed during the first phase were interspersed.

The Mere Exposure Effect became evident when the subject made significantly more positive assessments of the objects initially exhibited than of all the stimuli first presented in the final phase of assessment.

Factors that determine this

There are several factors that determine the Effect of Mere Exposure:

1. Type of stimulus

The effect is favorably induced by stimuli of all kinds: words, images, facial expressions, ideograms, polygons, etc.

However, if exclusively abstract figures are used, does not occur, or if it does, it is in a subtle way .

2. Complexity of stimuli

The effect is greater with complex stimuli than with simple ones; this phenomenon has been demonstrated in several studies .

3. Exposure number

The greater the number of exposures, the greater the effect; however, it is not a linear effect; after 10 or 20 exposures, the changes that occur are minor.

To illustrate this, Zajonc (1972) alluded to a logarithmic relationship that increases until it reaches a “ceiling effect” . Other researchers refer to a relationship that can be represented as an inverted U-shape.

4. Sequence of exposure

The Mere Exposure Effect will vary depending on whether the stimuli used are the same or whether they vary; although few studies have been conducted on this and the results are diverse, it is known that studies that have used heterogeneous (diverse) stimuli to produce the Mere Exposure Effect provide less robust results.

5. Duration of exposure

There are few studies that have compared the effect that the duration of the stimulus has on producing the Mere Exposure Effect. One author in particular, Hamid (1973), used an inverted U to explain the relationship between duration and effect obtained from his studies.

6. Stimulus recognition

The fact that the stimulus is familiar to the person (i.e., that the stimulus is “recognized”), is not necessary for the Mere Exposure Effect to occur, and several studies have demonstrated this. There are even studies that suggest that recognition or familiarity reduces the effect.

7. Interval between exposure and testing

Here there is a disparity of opinions and results ; while there are some studies that find no change in relation to whether the interval between test and exposure is a few minutes or several weeks, other studies claim that there is an increase in the Mere Exposure Effect when the test phase is delayed after the initial exposure.

Causes of the effect

In more current studies, Zajonc (2000) is of the opinion that the Mere Exposure Effect is not mediated by subjective factors (e.g., by the familiarity of the stimulus, as we have discussed), but by the “very objective history of exposures”; in fact, the Mere Exposure Effect is more consistent under subliminal conditions. The author proposes the possibility that the effect may be mediated by some kind of classical conditioning.

Thus, in the Mere Exposure Effect, repeated exposure to certain stimuli could be understood as a conditioned stimulus (CS) , while the response preference would be the conditioned response (CR). This CR is analogous to the unconditioned response (IR), which is elicited by the tendency towards innate exploration.

Bibliographic references:

  • Bargh, J. A. (2001). The Psychology of the Mere. In J. A. Bargh and D. K. Apsley (Eds.), Unraveling the complexities of social life (pp. 25-37). Washington, DC: American Psychology Association.
  • Martínez, F., Sánchez and Campoy, G. (2003). Effect of mere exposure with presentations below the target threshold. Electronic Journal of Motivation and Emotion, 6(14-15).
  • Zajonc, R. B. (1968). Attitudinal effects of mere exposure. Journal of Personality and Social Psychology, 9(2), 1-27.
  • Zajonc, R. B. (2000). Feeling and thinking: Closing the debate over the independence of affect. In J. P. Forgas (Ed.) Feeling and thinking: The role of affect in social cognition. Cambridge: Cambridge University Press.