Imagine that you own a transport business and that you need to hire a driver for a new truck that you have bought. You put an advertisement for this job and a person turns up in your office to be interviewed. In this interview, the person says, “When I was in school, I belonged to the school football team and scored many goals”. Now, would you employ this person just based on the fact that he or she was a good football player in school? Hopefully, you would not, as playing football does not necessarily make one a good truck driver!
Unfortunately, in reality, one’s brain can have the tendency to assume that a person is good at something just based on the fact that the person is good at something else, even though that other skill may not be relevant to what one is assessing. Psychologists have named this type of illogical thinking, the “halo effect”.
The following short examples of the halo effect will help you to understand it better.
Example 1
Imagine that you have unfortunately injured one of your knees after tripping on something and that you will need to have surgery in a few weeks to repair the damage. You find that your local hospital has two surgeons who can repair your knee and of course, you want to choose the best one. To decide as to which one of the two surgeons you want to operate on your knee, you make appointments to meet each of them.
The first surgeon you meet is wearing a very nice suit and has put on a perfectly matched tie. His hair is perfectly combed and in general, he looks great. You have a bit of a discussion with him and then go to see the other surgeon.
The other surgeon looks very different from the first one. His suit is shabby and a bit worn out. His tie does not match the suit and his hair is a bit messy as well. Essentially he does not look as great as the first surgeon.
Now, which surgeon will you choose to repair your knee?

I guess that if you were in this position in real life, you would choose the well-dressed surgeon as being the best one to operate on your knee. This however would be an illogical choice, as the way a surgeon dresses has nothing to do with how good his surgical skills are. In fact, it may even be possible that the surgeon who is overly worried about his appearance may be really bad at how he performs surgery! Instead of relying on appearance, perhaps a better way to work out which surgeon is better would be to ask the surgeons for their success rate and maybe check online reviews about them.
Example 2
Imagine that a certain car company makes very nice luxury cars. The cars are well-made, have beautiful styling, and have very high-quality engines. To enlarge their business, this car company then decides to also run a chain of luxury hotels and advertises this everywhere.
Now imagine that there is a person called John who loves luxury cars and admires the car company a lot. One day, John decides to go on holiday and he needs to book a hotel room. Assuming that the hotels run by the car company would be as great as the cars they make, John promptly books a room at one of their hotels.
However, when John stays at the hotel run by the car company, he discovers, to his great disappointment, that the hotel is being run very poorly. His room in the hotel is dark, the bed is very uncomfortable, and even the food is very ordinary. When booking the hotel room, John’s brain did the halo effect type of illogical thinking which made him wrongly assume that a company that makes good cars will also run hotels well, when in reality, making cars and running hotels are very different things.
As you have seen in the above examples, the halo effect can cause one to make incorrect decisions. When making an assessment of something, make sure to use only criteria that are relevant to what you are assessing.