The halo effect is a cognitive bias that affects the way people interpret information about someone or something based on their overall impression or one specific trait. It is the tendency for positive impressions of a person, company, country, brand, or product in one area to positively or negatively influence ones opinion or feelings in other areas. The term was coined by Edward Thorndike in 1920.

The halo effect can occur in various contexts, such as psychology, product and branding, and web user experience. For example, if a person finds someone attractive, they may assume that the person is also kind, intelligent, and sociable, even if they have never interacted with them. Similarly, if a user likes one aspect of a website, they are more likely to judge it favorably in the future.

The halo effect can also work in the opposite direction, known as the reverse halo effect or horns effect, where a negative overall impression of a person influences the perception of their specific traits or abilities. For example, negative traits or shortcomings of an individual can overshadow their positive qualities, leading to biased judgments and evaluations.

In summary, the halo effect is a cognitive bias that can affect the way people interpret information about someone or something based on their overall impression or one specific trait. It can occur in various contexts and can work in both positive and negative directions.