Terms such as "halo effect", "prejudice effect" and "halo phenomenon" refer to an exaggerated social impression formed in the process of interpersonal communication, which, like the brilliance of the sun and the moon, expands around under the action of clouds to form a halo effect. It is often shown that a person's initial impression of another person (or thing) determines his overall view, but he can't see the true quality of the other person, forming a "prejudice" between good and bad. Therefore, the halo effect can also be called "a little general effect". It is the result of generalization and rigidity of subjective inference.

Dean designed an experiment: let the subjects look at some photos. Some people in the photos are very attractive, some are ordinary, and some are poor; Then, the subjects were asked to evaluate these people with words unrelated to charm. The results show that people who are good-looking score high in all aspects, while those who are not good-looking score low in all aspects. This phenomenon, which is induced and deduced from cognitive characteristics, is called halo effect, or "halo effect". Judging people by their appearances is the halo effect of first acquaintance.

In photographic terms, it can also be called halo effect. "Halo" is a photographic term. Anyone who knows photography knows that photographic imaging is caused by exposure on the emulsion layer of the negative. When the light is too strong, it will not only enter the emulsion layer, but also pass through the emulsion to reach the film base and reflect back, resulting in the secondary light of the emulsion layer. In this way, a shadow similar to halo will appear around the image, which is the so-called halo phenomenon.

Halo phenomenon will affect people's overall and accurate cognition of things and make people feel fuzzy about the true color of images. Psychological research shows that similar phenomena sometimes occur in people's psychological activities. As people often say, "it is better to see one thing than the rest." Therefore, psychologists call this strong impression of people and things halo effect.

Halo effect can make or cheat people. We should treat my halo effect correctly, give full play to its positive aspects, prevent its negative effects and overcome the prejudice in social cognition.