Halo Effect
Edited by Paweł Raja, PhD · Published
Definition
Halo Effect is the halo effect is the tendency for one positive impression of a person, brand or product — such as attractiveness, warmth or a single standout strength — to spill over into favorable judgments of their other, unrelated qualities.
- Also known as:
- Halo error, Halo bias
- Category:
- Judgment & Belief
- Impact:
- High
- Landmark study:
- Thorndike (1920)
- Evidence here:
- 5 cited studies
Why it happens: the psychology of halo effect
The psychologist Edward Thorndike named the effect in 1920 after noticing a problem in military ratings. Commanding officers had rated soldiers separately on qualities such as physique, intelligence, leadership and character, yet the ratings agreed with one another far more closely than distinct qualities plausibly could. Raters seemed to form a general impression of each man as rather good or rather inferior and let it color every specific judgment — what Thorndike called 'a constant error in psychological ratings.'
Physical attractiveness is the most studied source of halo. Dion, Berscheid and Walster (1972) found that people assumed attractive individuals had more socially desirable personalities and would lead more successful lives — 'what is beautiful is good.' Landy and Sigall (1974) found that male students evaluated an essay more favorably when it was attributed to an attractive woman. A meta-analysis by Eagly and colleagues (1991) refined the picture: the attractiveness halo is strong for judgments of social competence, more modest for intelligence, and weak for integrity and concern for others.
The halo effect is hard to catch in yourself. In Nisbett and Wilson's (1977) study, students who saw a warm or cold version of the same instructor rated his appearance, mannerisms and accent in line with their overall liking, and did not realize their global impression had done the work. Psychologically, an overall evaluation forms quickly and then acts as a lens: where information about a specific trait is missing or ambiguous, people fill the gap with the general impression, and later evidence is read in its light, much as in confirmation bias.
Organizations and brands get halos too. Phil Rosenzweig's book The Halo Effect (2007) argued that business writing often describes a company with strong results as having brilliant strategy, leadership and culture, then redescribes the same traits as weaknesses when results turn. In marketing, a strong reputation in one product line lifts perceptions of others, and one appealing feature can make a whole product seem better. The halo effect is related to the affect heuristic, the attractiveness stereotype and first-impression bias.
Halo Effect examples
In an experiment by Nisbett and Wilson (1977), students watched a video of the same college instructor behaving either warmly or coldly. Those who saw the warm version rated his appearance, mannerisms and accent as appealing; those who saw the cold version rated the same features as irritating, without realizing that their overall impression had shaped those ratings.
- A charismatic candidate who interviews well is assumed to be more competent and conscientious than their track record shows.
- A manager rates an employee highly on every item of a performance review because of one standout project.
- Investors assume a company with a famous founder or an admired brand must also be a good investment, whatever the price.
- A snack labeled 'organic' or 'low fat' is assumed to be healthier overall — the so-called health halo.
- A polished, expensive-looking website makes an unknown seller seem more trustworthy.
- A teacher grades an essay more generously when it comes from a student who is attentive and well-behaved in class.
- A celebrity's appeal transfers to the unrelated products they endorse.
- The reverse also happens: a single typo on a resume or an awkward first minute drags down judgments of a candidate's competence — the horn effect.
Halo effect vs horn effect
The horn effect, also called the reverse halo or devil effect, is the negative mirror image: one disliked trait drags down judgments of everything else. Thorndike's original description already covered both directions, describing a tendency to think of a person in general as rather good or rather inferior and to color every specific judgment with that feeling.
In practice the two often appear together in the same decision. An interviewer impressed by one candidate's confidence and put off by another's nervousness may end up rating the first higher, and the second lower, on skills neither interview actually tested.
The halo effect in hiring and performance reviews
Rating scales were where Thorndike first spotted the effect, and they remain where it does the most damage. Unstructured interviews and holistic reviews invite a single impression to set every score. Structured interviews, which ask every candidate the same questions and score each competency on a defined scale, and reviews that rate specific behaviors with evidence, limit how far one trait can spread.
How to avoid the halo effect
- Break the judgment into parts. Rate each quality separately, on its own evidence, before forming an overall view.
- Score across people, not across criteria. Evaluate every candidate or option on the first criterion, then all of them on the second, so one strong impression cannot flood a whole scorecard.
- Remove irrelevant cues. Review work samples, essays or code blind where you can, without names, photos or institutional affiliations.
- Ask what you actually know. For each positive (or negative) inference, ask what direct evidence supports it, and mark the gaps you filled with a general impression.
- Use several independent raters and compare their scores before discussing, so one person's halo does not become the group's.
- Watch for the horn effect too. A single poor first impression deserves the same scrutiny as a single dazzling one.
How to design for it (nudge strategy)
Evaluate one attribute at a time against structured criteria, remove irrelevant cues such as photos, names and brands where possible, and score each dimension separately before forming an overall judgment.
Ethical use: design for choices people would endorse on reflection — a nudge, not sludge. Be transparent and keep opting out easy.
Key studies
Officers' separate ratings of soldiers' physique, intelligence, leadership and character correlated too highly, showing a general impression coloring judgments of specific qualities.
Thorndike, E. L. (1920). A constant error in psychological ratings. Journal of Applied Psychology, 4(1), 25–29. DOI →
Physically attractive people were assumed to have more socially desirable personality traits and to lead better, more successful lives.
Dion, K., Berscheid, E., & Walster, E. (1972). What is beautiful is good. Journal of Personality and Social Psychology, 24(3), 285–290. DOI →
Male students rated an essay more favorably when it was attributed to a physically attractive female writer than to an unattractive one.
Landy, D., & Sigall, H. (1974). Beauty is talent: Task evaluation as a function of the performer's physical attractiveness. Journal of Personality and Social Psychology, 29(3), 299–304. DOI →
Whether an instructor appeared warm or cold changed how appealing students found his appearance, mannerisms and accent, and students were unaware of this influence.
Nisbett, R. E., & Wilson, T. D. (1977). The halo effect: Evidence for unconscious alteration of judgments. Journal of Personality and Social Psychology, 35(4), 250–256. DOI →
The attractiveness stereotype was strong for perceived social competence, moderate for intelligence, and weak for integrity and concern for others.
Eagly, A. H., Ashmore, R. D., Makhijani, M. G., & Longo, L. C. (1991). What is beautiful is good, but...: A meta-analytic review of research on the physical attractiveness stereotype. Psychological Bulletin, 110(1), 109–128. DOI →
Related biases
Halo Effect: frequently asked questions
What is the halo effect?
The halo effect is the tendency to let one positive trait of a person, brand or product shape our judgments of their other, unrelated traits — for example, assuming an attractive or confident person is also intelligent and honest.
What is an example of the halo effect?
Assuming a well-dressed, articulate job candidate is also more competent; believing a product is better because a celebrity you admire endorses it; or assuming a food is healthy because it is labeled organic.
Who discovered the halo effect?
Edward Thorndike named it in 1920, after finding that military officers' ratings of different qualities in the same soldier were far more consistent with one another than they should have been.
What is the opposite of the halo effect?
The horn effect (or reverse halo effect), in which one negative trait leads people to judge someone's other qualities more harshly.
What is the halo effect in marketing?
It is when a positive impression of one product, feature or brand spreads to others — a strong flagship lifting perceptions of the rest of a range, or a 'natural' label making a whole product seem healthier.
How is the halo effect different from confirmation bias?
The halo effect is one global impression spreading across unrelated traits. Confirmation bias is the broader tendency to seek and interpret evidence in line with what we already believe. A halo often works through confirmation bias, as later information is read in the light of the first impression.
Cite this page
Raja, P. (Ed.). (2026, 8 Oct 2026). Halo Effect. Behavioral Economics Lab. https://www.behavioraleconomicslab.com/biases/halo-effect