The halo effect (Halo Effect) is one of the cognitive biases most frequently encountered in everyday life and it is an erroneous generalization inspired by a single characteristic or quality of the object or person.
The term was coined by Thorndike in 1920 and derives from his research in the military, when he detected the innate tendency of soldiers to attribute a series of positive characteristics to their superiors once they discover a positive characteristic or, conversely, consider them negatively starting from a negative feature Horn effect.
Later, Nisbett and Wilson carried out an experiment in which two groups of students from the University of Michigan (118 people) had to observe two videos in which a professor lectured. He was still the same professor, but in one video he was authoritarian while in the other he was cordial and affable. Each group saw only one of the two characteristics of the professor.
Each student was then asked to describe the professor's appearance. Students who saw the positive side described him as a nice and attractive person while those who saw the negative side described him as a negative person. It was interesting that by asking the students if the teacher's attitude had influenced their judgment, they all said no, convinced that they were objective.
The same effect was observed in another experiment carried out a few years later by Karen Dion. On this occasion the participants were shown several photos and asked to give a judgment on the person who appeared in the photo. Physically attractive people were described as responsible, affable and likeable. This was also true when the interviewees did not personally know the subject.
It should be emphasized that the halo effect is not only evident in relationships with people but also with products. An example of a halo effect is the one related to the taste of Coca Cola that you can find in the article: “Coca Cola or Pepsi”.
What psychological mechanisms are behind the halo effect?
This bias is a cognitive distortion that affects the way we perceive reality but the psychological mechanisms that give rise to this form of evaluating the world are still under discussion.
Thorndike believed that the halo effect was much more than a mere presumption or interpretation of the meanings of isolated qualities, considering that the origin of the halo lay in our inability to resist the affective influence of the global evaluation versus the evaluation of specific qualities. In other words, we are not quite capable of separating an isolated feature with a strong emotional impact, from our global vision of the person, fact or product in question.
Nisbett and Wilson believed that the origin of the halo effect lay not so much in the emotional impact of the isolated feature but rather in people's lack of awareness, which could allow them to separate an individual quality from a global judgment.
On the other hand, Solomon Ash thought that the halo effect was the consequence of a cognitive dissonance. If the first impression we make of a person is positive, then we will have the tendency to evaluate that person as a whole always in a positive way, in order not to affect the coherence between emotions, behaviors and beliefs.
Personally I think that the people around us and reality itself are very complex, nothing is black or white and sometimes the variety overwhelms us or, simply, we do not have all the psychological tools necessary to deal with it.
So, we tend to simplify and let ourselves be carried away by the first characteristic we know of the object. Many times this mechanism works at an unconscious level, so we do not even realize the halo effect, but this is just an attempt to make sense, logical and simple, to a reality that we do not know in depth.
Of course, in this regard, the halo effect will be more or less intense or more or less conscious, depending on the emotional impact of the individual characteristics we know.
The halo effect would be the tendency to simplify starting from an isolated characteristic with the aim of maintaining a congruous vision of the world and interpersonal relationships, when we do not have sufficient data to develop a deep and complex judgment on people or phenomena of our reality.