Mere Exposure Effect

EMPIRICAL EVIDENCE: MANIPULATING PREFERENCES THROUGH CONTROLLED EXPOSURES

The fundamental nature and importance of affect has been demonstrated repeatedly in a remarkable series of studies by Zajonc and his colleagues (see, e.g., Zajonc, 1968; Zajonc & Markus, 1982). The concept of stimulus exposure is central to all of these studies. The central finding is that, when objects are presented to an individual repeatedly, the “mere exposure” is capable of creating a positive attitude or preference for these objects.

In the typical study, stimuli such as nonsense phrases, or faces, or Chinese ideographs are presented to an individual with varying frequencies. In a later session, the individual judges these stimuli on liking, or familiarity, or both. The more frequent the prior exposure to a stimulus, the more positive the response. A meta-analysis by Bornstein (1989) of mere exposure research published between 1968 and 1987 included more than 200 experiments examining the exposure–affect relationship. Unreinforced exposures were found to reliably enhance affect toward visual, auditory, gustatory, abstract, and social stimuli.

Winkielman, Zajonc, and Schwarz (1997) demonstrated the speed with which affect can influence judgments in studies using a subliminal priming paradigm. Participants were “primed” through exposure to a smiling face, a frowning face, or a neutral polygon presented for 1/250th second, an interval so brief that there is no recognition or recall of the stimulus. Immediately following this exposure, an ideograph was presented for 2 seconds, following which the participant rated the ideograph on a scale of liking. Mean liking ratings were significantly higher for ideographs preceded by smiling faces. This effect was lasting. In a second session, ideographs were primed by the other face: the face not associated with the stimulus in the first session. This second priming was ineffective because the effect of the first priming remained.

It is not just subliminal smiles that affect our judgment. La France and Hect (1995) found that students accused of academic misconduct who were pictured as smiling received less punishment than nonsmiling transgressors. Smiling persons were judged as more trustworthy, good, honest, genuine, obedient, blameless, sincere, and admirable than nonsmiling targets.

The perseverance of induced preferences was tested by Sherman, Kim, and Zajonc (1998), who asked participants to study Chinese characters and their English meanings. Half of the meanings were positive (e.g., beauty), half were negative (e.g., disease). Then participants were given a test of these meanings followed by a task in which they were given pairs of characters and were asked to choose the one they preferred. Participants preferred characters with positive meaning 70% of the time. Next, the characters were presented with neutral meanings (desk, linen) and subjects were told that these were the “true” meanings. The testing procedure was repeated and, despite learning the new meanings, the preferences remained the same. Characters that had been paired initially with positive meanings still tended to be preferred.

These various studies demonstrate that affect is a strong conditioner of preference, regardless of whether the cause of that affect is consciously perceived. They also demonstrate the independence of affect from cognition, indicating that there may be conditions of affective or emotional arousal that do not necessarily require cognitive appraisal. This affective mode of response, unburdened by cognition and therefore much faster, has considerable adaptive value.