What Is… a Heuristic in Psychology

Examples of heuristics (cognitive rules of thumb)

In this series, I dig a little deeper into the meaning of psychology-related terms. This week’s term is heuristic.

A heuristic (from the Greek “to discover”) is a mental rule of thumb or shortcut that allows our brains to process information and arrive at conclusions more quickly. I recently wrote about philosophical razors, which are a type of logical heuristic. This post will cover psychological heuristics, which you probably use regularly without even realizing it.

Heuristics aren’t necessarily a bad thing. They’re efficient, they don’t require conscious thought, and they handle unimportant stuff pretty well. The problem comes when we get too attached to our conclusions and believe that we arrived at them logically. Despite the logical appearance, our mind just made a flying leap and that’s where it happened to land.

Heuristics were first described by psychologists Amos Tversky and Daniel Kahneman in a 1974 paper. They identified three of them: representativeness, availability, and anchoring and adjustment. Several more have since been identified.

Anchoring and adjustment

People will evaluate pricing based on the initial anchor point they’re given. A used car might be worth $6000, but if the dealer’s asking price is $10,000, that’s what your brain wants to use a reference point. You end up adjusting your evaluation and thinking you got an awesome deal by only paying $7500. The dealer, on the other hand, is happy you fell for their trick and paid too much.

When you go to a clothing store, either in-person or online, sale items will always be clearly marked with the original price. That serves as the anchor, making you think you’re getting a great deal, even if the original price was way higher than it deserved to be in the first place. I can get sucked into this one; I am cheap, and feeling like I got a great deal is very satisfying.

Availability heuristic

We judge the frequency of events based on the example that comes to mind most easily; this is known as the availability heuristic. Car crashes are waaaaaay more common than plane crashes; however, because plane crashes are big news and car crashes are not, the way we estimate likelihood is skewed by plane crashes being more front of mind. Car crashes become background risk, while some people are terrified of flying.

We also overestimate violent crime rates and misjudge trends in those rates because those types of crimes get a lot of media attention.

Familiarity heuristic

The familiarity heuristic is a variation of the availability heuristic, and it means that if something comes to mind quickly, we’re likely to think it’s the right/safe choice. We’re also likely to overestimate the safety of familiar environments, to the point that we may miss seeing major hazards. This may be part of why you’re most likely to have a car accident when you’re close to home.

Representativeness heuristic

Our brains like to create social categories and come up with representative examples of those categories. When someone comes along who reminds of one of those representative examples, we slot them into that category and apply all the beliefs and judgments we have around the category to the person we’ve just shoved in there. That’s the representativeness heuristic—hello, stereotypes.

This is also why we’re bad at identifying what’s random and what’s not. We expect a random set of data to look a certain way… but we’re totally out to lunch. If you flip a coin ten times and it comes up heads each time, you might think that it’s a trick coin or, at the very least, that there’s a higher likelihood of flip #11 coming up tails, because getting 11 heads in a row just doesn’t happen randomly. Except it does, and you’d be wrong, because the odds of every flip are 50:50, and the coin has no memory of what’s already happened. Even if it did, it probably wouldn’t care.

Scarcity heuristic

The scarcity heuristic means that the rarer something is, the more valuable it’s believed to be. When toilet paper started flying off shelves because of panic buying in spring 2020, the scarcity heuristic kicked in and people start hoarding enough toilet paper to last for the next decade.

Think of diamonds and cubic zirconia. Diamonds cost more because they’re rare, so people are willing to shell out the big bucks for them even though they look pretty much the same to the average person.

Social proof

We are sheeple, and if other people are doing it, we think we probably should be too. Add this to the scarcity heuristic, and it’s not just a few nutters hoarding toilet paper; the social proof of seeing others walking out of the store with a cart full of toilet paper everyone makes everyone want to get in on the action.

Similarly to the social proof heuristic, we make some moral evaluations based on how commonly we observe a behaviour. The more common that a behaviour is, the more likely we are to deem it a moral action, even if the behaviour itself is actually selfish. Baaaaaa!

Being aware of our thinking patterns

I find it fascinating that our brains try so hard to be helpful, but can totally miss the boat. Perhaps the takeaway is that thoughts just aren’t reliably accurate. Someone (although I don’t know who) has said “don’t believe everything you think”, and that’s very good advice. There’s some good stuff that our minds come up with, but there’s also a lot of nonsense floating around in there. Deciding which is which isn’t necessarily easy.

Do these heuristics sounds familiar to you (not necessarily the name of the heuristic, but the shortcuts they refer to)? How do you think we can get around our natural tendency to believe in nonsense thoughts?

You may also be interested in the post What Is… a Cognitive Bias.


The Psychology Corner: Insights into psychology and psychological tests

The Psychology Corner has an overview of terms covered in the What Is… series, along with a collection of scientifically validated psychological tests.

Ashley L. Peterson headshot

Ashley L. Peterson


Ashley is a former mental health nurse and pharmacist and the author of four books.

12 thoughts on “What Is… a Heuristic in Psychology”

  1. Thanks for this! I am most amazed at the Social Proof heuristic. It is absolutely bonkers that we see behavior as moral just because it is common. As you say in your post – “The more common a behaviour is, the more likely we are to deem it moral action, even if the behaviour itself is actually selfish.” Scares me to even think about what that could mean…. Good to know that it happens so as to prevent where possible? Can we prevent?

  2. I found heuristics really interesting during my degree. I remembered the research on car accidents in familiar places and thought it absolutely makes sense as people can often drive ‘on autopilot’ and not even remember the journey, thinking that’s okay because they know it like the back of their hand.

    A good reference with the scarcity heuristic and toilet paper. I wonder if the Toilet Paper Shortage of 2020 will feature in the Psych textbooks for future generations to learn from.

    Social Proof is also really interesting where Covid is concerned. Must have Covid on the brain because I kept thinking of different examples throughout your post. I wasn’t able to get an N95 mask until, ironically, just after I had Covid, so by early April I was wearing a mask every time I left the house. I got so many strange looks. I was the only bugger doing it. Luckily I don’t much care that I look like a moron when I know I’m doing the right thing. Now it’s mandatory and ‘everyone’s doing it’. Or at least, some are. The more you see wearing masks, the more likely you will and that you’ll feel it’s necessary and effective. If you’re surrounded by selfish idiots that won’t wear a mask because ‘nobody can tell me what to do, innit’, then you’re more likely to shun masks and think they’re useless and stupid.

    The way in which our brains work in order to be helpful or come to conclusions and inferences more quickly really is fascinating. The way in which it can go wrong, be victim to bias or be less effective is all the more fascinating, particularly because the landscape we’re now is in so different to that in which the human brain was first adapted to, without tech or cars or the seemingly odd social norms and such we have now.

    1. It really is fascinating, and COVID has brought up so many examples. I think the psych textbook writers are going to be busy for decades talking about COVID.

  3. We think that we-people in the West are judgy humans by practice. So shortcuts to judgments and assessments make sense. Maybe only by acknowledging cultural relativism can we see that most of our assessments are not truths to be set in stone but a product of the scripts (neurological code) written in our brains by our parents/caregivers, institutions, media, etc.

    It’s a Matrix argument, and most people like the pill that keeps you in the simulation because waking up to the artificial and dependent nature of most conclusions and social customs can be terrifying.

    1. I might not be remembering this correctly, but I think heuristics aren’t culture-dependent and aren’t taught. They’re strategies the mind uses automatically to reduce workload.

      There absolutely are culture-bound judgments and constructions of what truth is, but I think heuristics are a different process.

  4. I love how you take a serious subject and often give it a flip of your feistiness. Interesting to contemplate at what point we shake off the ‘flying leaps’ and do some real thinking.

  5. Thanks for this article! Always wondered what “heuristic ” meant. When I was in grade ten I took marketing, back then it was print, radio, and window display. We learned that you can price something at $2.99 and people will buy it. Take the same product price it at $3.00 and they will leave it sit on the shelf.
    It really is all about psychology, it sounds weird, but these things work.

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