Where it comes from
The phenomenon was noticed as early as the beginning of the twentieth century: officers were asked to rate their subordinates on different qualities, and the ratings tended to come as a package. Someone considered well-groomed received high scores for both intelligence and character.
Later, researchers tested it more carefully. Participants watched the same person in two recordings - friendly in one and cold in the other - and in the second case, they found even the person's appearance and accent less appealing.
The most troubling part is how invisible it is. People confidently denied that their overall impression had affected their specific ratings, even though the influence was obvious in the data.
The reverse also works: one off-putting trait pulls everything else down. It's the same mechanism, and studies sometimes call it the horns effect.
Where it gets in the way
- Rate one trait at a time and write down your rating before looking at the others
- Separate impressions from facts: "I like them" on one side, "what they did" on the other
- Remove irrelevant information where possible: anonymized work, auditions behind a screen
- Ask yourself what you actually know about the person and what you inferred
- Judge competence by the way someone speaks and looks
- Test your first impression with questions whose answers you already know
- Assume you're immune: in experiments, confidence in this changed nothing
- Make a decision right after a pleasant conversation
This effect has long been measured in job interviews: an appealing appearance and confident speech raise ratings of abilities that were not tested in the conversation at all. That's where structured interviews come in.
You can see it in relationships too, especially at the beginning. Falling in love assigns people traits no one has observed, and later disappointment is often not a change in the person but the halo fading.
It's also useful to remember that the halo does not work symmetrically over time. It forms in seconds but takes months to come apart - and all that time, it affects what you notice and what you miss.
What is the halo effect?
What was the most troubling feature of this effect in experiments?
Sources
- The halo effect was described in 1920 based on officers' ratings and has been replicated many times: an overall impression of a person shifts ratings of their individual qualities. In experiments, participants were unaware that their overall impression was influencing their specific judgments. The effect has been shown in assessments of competence during hiring and underlies recommendations for structuring interviews
Next in the “Attraction” series
3 articles in full on the site, 4 more in the app
