Halo effect
A good first impression lights up everything… even when it has nothing to do with it.
Observed for over a century in workplace, educational and social evaluations. It's one of the most consistent judgement biases.
Sound familiar?
You see someone very good-looking and well dressed and, without knowing anything else, they also strike you as smarter, kinder and more trustworthy. Nobody has shown you any of that, but your mind has already made up its mind.
What it is
The halo effect is the tendency to let a single trait of a person (or a brand, or a product) shape how we judge everything else about them. If we like something, we credit it with more positive qualities; if we dislike it, the opposite happens (sometimes called the "horns" effect).
The name comes from the halo of light around saints: one trait "lights up" the whole person.
The experiment
In 1920, Edward Thorndike looked at how US Army superiors rated their subordinates on traits such as physique, intelligence, leadership and character.1 He found the ratings were far too closely linked: if someone was rated highly on one thing, they were rated highly on almost everything. Thorndike called it a "constant error" in ratings.
In 1977, Richard Nisbett and Timothy Wilson went further.2 They showed students a video of a lecturer with a foreign accent. In one version he behaved warmly, in the other coldly. Those who saw the warm version rated his appearance, mannerisms and even his accent as more appealing. The most unsettling part: they denied that liking him had influenced those ratings.
What we know today
The halo effect has been documented in many settings. A classic 1972 study titled "What is beautiful is good" showed that attractive people were credited with more desirable personality traits and a brighter future, based on nothing more than a photo.3
What makes it so hard to avoid is exactly what Nisbett and Wilson showed: it happens without our noticing, and when asked, we believe our judgement was objective.
Myth vs. reality
Myth "I judge people for who they are. I don't get carried away by appearances."
Reality The participants in these studies thought so too. The halo effect works unconsciously, so feeling objective doesn't mean you are.
In everyday life
- Separate your ratings: if you have to evaluate someone (a candidate, a piece of work), score each aspect separately using criteria set in advance.
- Be wary of "I've got a good feeling about this" for important decisions: ask for concrete evidence.
- Advertising: celebrities sell products because their halo rubs off on the brand.
Sources
- Thorndike, E. L. (1920). A constant error in psychological ratings. Journal of Applied Psychology, 4(1), 25–29. doi.org/10.1037/h0071663
- 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.org/10.1037/0022-3514.35.4.250
- Dion, K., Berscheid, E., & Walster, E. (1972). What is beautiful is good. Journal of Personality and Social Psychology, 24(3), 285–290. doi.org/10.1037/h0033731