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

Halo effect


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.


Examples for 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 a description of what she likes to do in life. 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.
  • 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.
  • When engaging with political discussion partners, people viewed attractive individuals as more knowledgeable and persuasive, and as better sources for political information.

Furthermore, the halo effect isn’t just 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.


Why it 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.


The horns effect

The horns effect is a similar effect, 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 much more likely to rate them as being hyperactive and as having an 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.

(In terms of terminology, the halo effect technically encompasses both positive and negative influence. Sometimes however, the halo effect is used to specify positive influence, while the horns effect is used to specify 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 meant 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 for how a simple change in behavior can completely change the way people perceive you, and for how you can take advantage of the halo effect.


Variability in the halo effect

Keep in mind that the halo effect is not a clear-cut, all-encompassing effect that always influences your 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. The same variability also appeared in other studies on the topic.

This is just a reminder that human psychology is complex, and that while effects and 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 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 example for various types of cues, and show you how you can take advantage of them yourself, in order to improve your ability to remember.


How cues help us remember

When we think about memory, we often think about retrospective memory, which involves recalling things that we experienced in our past. Prospective memory, on the other hand, is a type of memory which involves remembering to perform actions in the future. In this post we will focus on how cues can help with our prospective memory, by reminding us to perform necessary, everyday functions.

Simply put, memory cues can be any external item or event 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.

These cues work by triggering an action or a memory of that action. They can often be more effective in doing this than internal memory cues, which are things such as thoughts, intentions, and mental reminders.

(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 and this paper on strategic and automatic processes in prospective memory retrieval).


Examples for external cues

Below are some examples for 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 could 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 it easy, so that every time you look at it you remember to relax a little.


The worst kind of example

While memory cues can help with small tasks, they can often make a big difference.

Unfortunately, one of the most common examples of people going on autopilot and forgetting to do things is parents leaving their kids in the car.

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 by 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 to run errands. “Luckily” for him, the kid fell asleep just as they left the house, and remained sleeping 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 sit 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 for a situation where a simple memory cue 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, 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.

While this is part of what makes it an effective reminder, using it 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. You can do one of two things:

  • 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 certain things which occur normally will serve as a cue for you- sometimes, you can take advantage of things you already encounter, and use them as a reminder of things 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 everyday.
  • 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 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 worthless if it is inconvenient enough that you don’t use it in reality.


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 then 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 doesn’t guarantee that Billy will survive, his odds certainly improved in comparison to what would have happened if he had decided to step in to 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 first automatically, he would have had a much better chance of surviving. 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 into 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, and letting the leader and the runner-ups weaken each other before attacking.
  • The first and 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.

I recommend it over the earlier version of the book (“Thinking Strategically”), because that’s what the authors themselves recommend. However, the difference between the two versions isn’t too crucial.