The Halo Effect: Why We Often Judge a Book by its Cover

Halo effect


The halo effect is a cognitive bias that causes our impression of someone in one area to influence our opinion of that person in other areas. For example, it can cause us to think that someone is more interesting if we find them physically attractive, and vice versa.

This effect is widely prevalent, and influences the way that we perceive not only other people, but also various other entities, such as various groups and companies. In the following article, you will learn about the halo effect, see examples of how it influences us, and understand how you can benefit from understanding its influence.


What is the halo effect

The halo effect is a cognitive bias that causes our impression of someone in one area to influence our opinion of that person in other areas. For example, if we think that someone is physically attractive, we often assume that they have a more interesting personality, compared to what we would assume if they were unattractive.


Why the halo effect influences us

The halo effect is essentially a type of confirmation bias, which is a cognitive bias that causes us to search for and interpret information in a way that confirms our preexisting beliefs.

Specifically in this case, being exposed to a single positive trait of an individual sometimes causes us to immediately form a positive impression of that person, even when we don’t know anything else about them. Then, in order to confirm our initial impression, we interpret other traits that that person has as positive too.


Examples of the halo effect

The halo effect influences how we look at other people in various ways:

  • What people think about a woman’s personality is influenced by how much she weighs. In one study, participants saw a picture of a woman, together with background information about her life and hobbies. One group received the original picture, while the other group received a picture where the woman wore padding, to make her look 50 pounds heavier. The participants rated the thinner woman as more attractive, as having a better personality, and as more likely to be successful at her career.
  • When engaging with political discussion partners, people viewed attractive individuals as more knowledgeable and persuasive, and as better sources for political information.
  • Men gave a higher rating to an essay when they thought that it was written by an attractive female author, compared to when they thought that it was written by an unattractive one.

Furthermore, the halo effect isn’t limited to the way we look at people. It can also, for example, affect the way we look at products and brands, making it a key effect in marketing, especially when it comes to assessing brand equity. Specifically, this means that if you have a positive impression of a certain brand, you’re more likely to buy products from that brand, even if the positive impression is not directly related to the product at hand.


The horns effect

The horns effect is a similar bias, where encountering someone’s negative trait causes us to assume negative things about other aspects of that person.

For example, a study on classroom behavior found that when young kids behaved in a defiant manner, teachers were more likely to rate them as hyperactive and as having attention-deficit hyperactivity disorder (ADHD), even when that was not the case.

In the context of marketing, this means that if you have a negative impression of a certain brand, you’re less likely to buy its products, even when the negative impression is not directly related to them.

Note: In terms of terminology, the halo effect technically encompasses both positive and negative influence. However, sometimes the halo effect is used to refer to positive influence, while the horns effect is used to refer to negative influence. This is why the horns effect is occasionally called a “reverse halo effect”, even though in practice both refer to the same type of confirmation bias.


What the halo effect means for you

The halo effect influences how you see others. Remember this, and account for it both in terms of positive as well as negative influence. That is, just because someone has a single positive trait (e.g. physical attractiveness), doesn’t mean that you should immediately put them on a pedestal. Similarly, just because someone has a single negative trait, doesn’t mean you should immediately disregard them.

The halo effect also influences how others see you. You can take advantage of this, by realizing that your traits and behaviors in one area influence how other people perceive you in other areas.

For example, one study let students listen to an interview with a college professor who spoke English with a European accent. There were two groups of students, each of which saw a slightly different version of the interview. In one version the instructor was warm and friendly, while in the other version he was cold and distant. Students who saw the warm instructor rated his appearance, mannerisms, and accent as appealing, while students who saw the cold instructor rated the exact same attributes as irritating.

This is an example of how, by taking advantage of the halo effect, you can make simple changes in your behavior that completely change the way people perceive you.


Variability in the halo effect

Keep in mind that the halo effect is not a clear-cut, all-encompassing effect that always influences our thoughts in the same way.

For example, in the case of people rating essays based on the attractiveness of the purported author, the effect only appeared when a man thought that he was rating an essay written by a woman. In the case of women rating an essay by a woman, and men/women rating an essay by a man, the physical attractiveness of the author did not play a role in their rating.

This, and similar forms of variability, also appeared in other studies on the topic.

This is just a reminder that human psychology is complex, and that while cognitive biases certainly play a role in how we think, not every decision that we make can be clearly attributed to them.


Summary and conclusions

  • The halo effect causes our impression of someone in one area to influence our opinion of that person in other areas.
  • For example, if we think that someone is physically attractive, we often also assume that they have a more interesting personality, compared to what we would assume if they were unattractive.
  • This is a type of confirmation bias, which causes us to interpret information in a way that confirms our preexisting beliefs. Specifically, it means that once we form an initial impression of someone, we try to interpret their traits in a way that matches that impression.
  • The halo effect influences how you see other people, which you can account for by not immediately deifying or vilifying someone based on a single trait.
  • The halo effect also influences how others see you, which you can take advantage of by understanding that your behavior in one area will influence people’s perception of you overall.


Setting Yourself Up to Remember: The Benefits of Memory Cues

Benefits of Memory Cues


There are so many things we have to remember to do every day, that we often end up forgetting quite a few of them. One way to remember them is to use external memory cues, which are objects or events that remind us of the things that we need to do. This article will explain to you how these cues work, give you examples of various types of cues, and show you how you can use cues to help you remember.


How cues help us remember

Memory cues are external objects or events that help trigger an action or a memory of that action. These cues can often be more effective in doing this than internal memory cues, which are things such as thoughts, intentions, and mental reminders.

By serving as a trigger, memory cues help us with our prospective memory, which is a type of memory that involves remembering to perform actions in the future. This is different than our retrospective memory, which involves recalling things that we experienced in our past.

Note: I won’t get into the specific cognitive mechanisms behind external cues here, but if you want to read more on the topic, you can start with this fMRI study on prospective memory, or this paper on strategic and automatic processes in prospective memory retrieval.


Examples of external cues

Simply put, memory cues can be any external thing that helps us remember what we need to do. For example, if you remember to brush your teeth in the morning because the toothbrush is right next to the sink where you wash your face, you could say that the toothbrush served as a memory cue.

Below are some examples of ways you can use external cues to remember to do things:

  • If you need to remember to floss your teeth, you can put the box with the floss on top of your tube of toothpaste.
  • If you need to remember to take a pill each morning, you can put the pills next to whatever you usually eat for breakfast, or in a visible location in the area where you eat.
  • If you want to start the day by writing a paper for a class instead of procrastinating on social media, you can put a piece of paper with a reminder on top of your keyboard.
  • You can also use cues to remember more abstract things. For example, you can use your watch as a reminder to take things easy, so that every time you look at it you remember to relax a little.


The worst kind of example

While memory cues usually help with small things, they can also make a big difference, and one of the most notable examples for this is in the case of parents forgetting their kids in the car.

This sort of event is unfortunately common. A study which analyzed heat-related deaths of young children in parked cars found that 73% of the children were left there by adults, half of which were unaware or forgot that they were leaving their child in the car. Often, the children were left behind by a family member who intended to take them to childcare, but forgot and went to work instead.

One father tells a story of how he used to always run errands by himself on Wednesday. One Wednesday however, the relative who usually babysits for him couldn’t come, so the dad took his 10-months-old son Will with him when he went grocery shopping. “Luckily” for him, the kid fell asleep just as they left the house, and remained asleep throughout the car ride. When they got to the grocery store, the dad rushed quickly out of the car and across the parking lot, in an attempt to avoid spending time in the freezing temperatures of the Massachusetts winter. Once he got to the grocery store, he realized that he forgot the grocery list on the passenger seat of the car. As he says next:

When I realized what else I had forgotten, I learned the true meaning of “panic attack.” I just stood there, paralyzed by a deeper fear than I have ever known. I could try to sugarcoat it by saying I was sleep-deprived and out of my normal routine—factual statements—but there was no denying another fact: I simply forgot about my son. If not for remembering the grocery list, there is a very good chance my boy would’ve been frozen to death upon my return.

This is an example of a situation where a simple memory cue (the grocery list), made a huge difference. If you have a kid yourself, you can implement this solution using intentional memory cues, by leaving your briefcase, phone, or wallet next to your kid when you drive with them in the car.

Some people even advocate leaving something like your left shoe behind, with the idea being that there’s no chance of you not noticing that you don’t have your shoe on. While this could work for some people, the problem with this is that it causes more inconvenience than leaving something like your phone or briefcase. This is risky, because the more inconvenient a cue is, the less likely you will be to use it every time, which makes it unreliable. The best memory cue is the one that strikes the balance between serving as an effective reminder, and being convenient enough to use consistently.


How to use cues to remember things

Cues are relatively simple to implement, using one of two ways:

  • You can set up certain things that will serve as cues- this means that you intentionally set up a certain item or event which will appear at an appropriate time and serve as a reminder. For example, you could leave your phone next to your kid when you enter the car.
  • You can also decide that something which occurs naturally will serve as a cue- this means that you intentionally take advantage of something that you encounter naturally or which occurs naturally in your everyday life, and use it as a reminder for something that you need to do. For example, you could make the act of opening the car door a reminder to check your pocket for your phone and wallet.


Summary and conclusions

  • Our prospective memory enables us to remember actions which we need to perform in the future, such as flossing our teeth every day.
  • External memory cues can aid our prospective memory, by triggering a mental reminder of actions that we need to perform.
  • External cues can often be more reliable in triggering necessary actions than internal cues, such as mental reminders that we set for ourselves.
  • You can either intentionally set up certain items/events to serve as cues, or you can pick things that you already encounter naturally in your everyday life.
  • The best reminders are those that are convenient to integrate into your routine, which ensures that you will use them consistently. Even the most effective reminder is useless if it is inconvenient enough that you don’t use it every time you should.


The Strategic Advantage of Being a Small Fish

The three gunslingers


Roland, Harry, and Billy are three outlaws who recently arrived at the town of Deadwood. After realizing there’s not enough room for the three of them in this town, they decide to meet at the town center at noon, and duel to the death.

The rules of the duel are simple: each one, in his turn, gets to fire one shot at whomever he wants. This goes on until there’s only one man left standing.

Roland is an excellent shot, who never misses. Harry, on the other hand, is pretty good but not perfect, and hits the target 70% of the time. Billy is the worst shot of the three, and can only hit the target 30% of the time.

Since Billy is the youngest, and the worst shot by far, the other two outlaws let him go first. Roland, being the best shot of the three, agrees to let Harry go second, and therefore to go last himself.

Billy, now realizing he probably made a mistake entering this duel, is standing there and contemplating who to shoot, since leaving town is unfortunately no longer an option. What should he do if he wants to survive?


Game theory analysis

When it comes to choosing who to shoot, Billy has two options:

  • Harry: If Billy shoots Harry and hits, Roland will kill him for certain on his turn, since Roland never misses.
  • Roland: If Billy shoots Roland and hits, Harry will shoot him on his turn. While Harry only has a 70% chance of hitting Billy, that’s quite a bit better than Billy’s 30% chance of hitting Harry, and this is made worse by the fact that Harry gets to take the first shot at him.

As you can see, neither option looks too promising, though option B looks a bit better than option A. But what if there was a third, preferable option?

In fact, the best strategy for Billy is to fire his first bullet straight in the air. Then Harry, on his turn, will shoot at Roland, since he knows that if he doesn’t then Roland will kill him during the next turn (because Harry poses a bigger threat to Roland than Billy does).

If Harry kills Roland, then Billy gets to fire the first shot at Harry, which is better for Billy than having Harry take the first shot at him.

If Harry misses Roland, then Roland kills Harry on his turn. Then, Billy gets one shot at Roland, before Roland wipes him out.

Regardless of whether Harry misses or hits, Billy is better off missing his first shot intentionally, rather than trying to hit one of the other two outlaws.


The lesson

Sometimes, if you’re a little fish in a big pond, it’s better to stand back, and let the big fish take each other out before you step into the race. Often, the leader and the runner-ups can be so weakened by their attacks on each other, that those far behind them can take advantage of this and catch up. While doing this still didn’t guarantee that Billy will survive, his odds certainly improved in comparison to what would have happened if he had decided to step into the game from the start.


Other things we’ve learned

Being the big fish can actually be a disadvantage- in this scenario, Roland has the lowest odds of survival, despite being the best shot of the three. Being the big fish didn’t guarantee victory for him; instead, it just made him a bigger target.

Don’t give up a potential advantage- if Roland hadn’t let the other two guys go before him automatically, he would have had a much better chance of survival. Just because you’re the big fish, doesn’t mean you should give up any potential advantages.

Know how to pick your battles- though Billy was able to improve his odds by thinking strategically and waiting before entering the fight, he is still more likely to die than not. The truly smart move for him would have been to avoid this duel in the first place.


Summary and conclusions

  • Often, being the big fish in a pond can be a disadvantage, because it makes you a bigger target.
  • If you’re the big fish, don’t automatically give up all your potential advantages; just because you’re stronger doesn’t mean you’re guaranteed victory.
  • If you’re the small fish, you can often benefit from hanging back before attacking, and letting the leader and the runner-ups weaken each other.
  • The most important strategic consideration is knowing how to pick your battles. If you enter the wrong battle, even the best strategic thinking might not help much.


This strategy and example come from “The Art of Strategy: A Game Theorist’s Guide to Success in Business and Life”. It’s a good read for someone looking to understand basic game theory and how it applies to real-life situations.