The mere exposure effect is a phenomenon in psychology where people tend to prefer something or someone that appears familiar. The more familiar something is, the more pleasant or trustworthy it will appear to be to the subject. This has a number of interesting ramifications for human behavior and plays an important role in the development of advertising campaigns and other measures intended to win trust or customer preference.
Research on the mere exposure effect shows that the more subjects are exposed to something, the more comfortable they will feel around it. Repeat exposures can lead to a situation where a subject will prefer the familiar to an unfamiliar alternative. This holds true even if the unfamiliar is actually a better choice. Consumers, for example, often reach for the brand name product on the shelf at the store even though the generic product may be functionally identical and less expensive.
Awareness of the mere exposure effect can play an important role in understanding human attraction and relationships. A patient will feel more comfortable with a known doctor, for example, and may not be as receptive to information and suggestions from a different doctor, even with a reference from her original doctor. Likewise, when people grow attracted to each other, the appearance of the object of their attractions is rated more highly if they see that person regularly. In school settings, children often mistrust and disobey a teacher at the start of the semester and then grow to like him after many classes together because he is familiar.
The advertising industry is well aware of the role the mere exposure effect plays in preference and product selection. Advertisers use campaigns to expose consumers to their products repeatedly so they appear familiar and stick in the mind of consumers. While a consumer might not decide to buy a product based on a specific ad, seeing the same brand and products over and over can influence her choice when she goes to the store to select something. The mere exposure effect can also explain why sales may drop after customers release new packaging, which is why many companies advertise a change in packaging to get consumers familiar with it before they make the switch.
This phenomenon plays an important role in human cognition. There may be a number of reasons behind the brain's tendency to prefer things it knows and recognizes over strangers, and it could be a positive adaptation to help humans process information and make decisions quickly. It can also be dangerous, however. A commuter may view a fellow commuter she sees on the train every morning as more trustworthy than another random stranger, for instance, even though she has no actual information to base this on.