50 Cognitive Biases

Fundamental Attribution Error. When someone else is late, it’s because they’re lazy. When you’re late, it was the traffic.

Self-Serving Bias. Attributing all your successes to skill or effect and all your screw ups to bad luck or a bad situation.

In-Group Favoritism. We tend to favor those in our in-group versus those who are different from us.

Bandwagon Effect. Everyone likes to jump on a trendy bandwagon.

Groupthink. Also just what it sounds like. Going along with the group to avoid conflict. The downfall of many a large organization.

Halo Effect. Assuming a person has other positive traits because you observed they have one. Just because someone is confident or beautiful doesn’t mean they are also smart or kind, for example.

Moral Luck. Assuming winners are morally superior.

False Consensus. Thinking most people agree with you even when that’s not the case.

Curse of Knowledge. Assuming everyone else knows what you know once you’ve learned something.

Spotlight Effect. Overestimating how much other people are thinking about you.

Availability Heuristic. Why we worry more about rare airplane crashes than objectively much deadlier road accidents. People make judgments based on how easy it is to call an example to mind (and plane crashes are memorable).

Defensive Attribution. Getting more upset at someone who commits a crime we feel we could have fallen victim to ourselves.

Just-World Hypothesis. The tendency to believe the world is just, so any observed injustice was really deserved.

Naive Realism. Thinking we have a better grasp of reality than everyone else.

Naive Cynicism. Thinking everyone else is just selfishly out for themselves.

Forer Effect (aka Barnum Effect). The bias behind the appeal of astrology. We see vague statements as applying specifically to us even when they apply to most everybody.

Dunning Kruger Effect. One of my personal favorites. This principle states that the less competent you are, the more confident you’re likely to be because you’re too incompetent to understand exactly how bad you are. The opposite is also true — those with greater skills are often plagued with doubt.

Anchoring. The way in which the first piece of information we hear tends to influence the terms or framing of an entire discussion.

Automation Bias. Over relying on automated systems like GPS or autocorrect.

Google Effect (aka Digital Amnesia). You’re more likely to forget it if you can just Google it.

Reactance. Doing the opposite of what you’re told when you feel bullied or backed into a corner. Very topical.

Confirmation Bias. We tend to look for and be more easily convinced by information that confirms our existing beliefs. A big one in politics.

Backfire Effect. Repeatedly mentioning a false belief to disprove it sometimes ends up just making people believe it more.

Third-Person Effect. The belief that others are more affected by a common phenomenon than you are.

Belief Bias. Judging an argument not on its own merits but by how plausible we think its conclusion is.

Availability Cascade. The more people believe (and talk about) something the more likely we are to think it’s true.

Declinism. Romanticizing the past and thinking we live in an age of decline.

Status Quo Bias. People tend to like things to stay the same, even if change would be beneficial.

Sunk Cost Fallacy (AKA Escalation of Commitment). Throwing good money (or effort) after bad to avoid facing up to a loss.

Gambler’s Fallacy. Thinking future probabilities are affected by past events. In sports, the hot hand.

Zero-Risk Bias. We prefer to reduce small risks to zero rather than reduce risks by a larger amount that doesn’t get them to zero.

Framing Effect. Drawing different conclusions from the same information depending on how it’s framed.

Stereotyping. Just what it sounds like — having general beliefs about entire groups of people (and applying them to individuals whether you know them or not).

Outgroup Homogeneity Bias. Seeing the diversity within the groups to which you belong but imagining people in groups to which you don’t belong are all alike.

Authority Bias. Putting too much stock in authority figures.

Placebo Effect. This isn’t strictly a cognitive bias according to Musk’s graphic, but still useful to know. If you think something will work, you’re likely to experience a small positive effect whether it really does or not.

Survivorship Bias. We remember the winners and forget about the many, invisible losers. Big in startups.

Tachypsychia. How exhaustion, drugs, or trauma mess with our sense of time.

Law of Triviality (AKA Bike-Shedding). Giving excessive weight to trivial issues while ignoring more important ones.

Zeigarnik Effect. Uncompleted tasks haunt our brains until we finish them.

Ikea Effect. We tend to overvalue things we had a hand in creating. (In my experience not true of Billy bookcases, but still …)

Ben Franklin Effect. We tend to think more positively about people once we’ve done a favor for them.

Bystander Effect. Again, not strictly a cognitive bias, but important. Describes how people are less likely to take responsibility to act if they’re in a crowd.

Suggestibility. Seen most often in children, this is when we mistake an idea or question someone else said for your own memory.

False Memory. Mistaking something you imagined for a memory.

Cryptomnesia. The opposite of the one above. Thinking a true memory is something you imagined.

Clustering Illusion. The tendency to “see” patterns in random data.

Pessimism Bias. Always seeing the glass as half empty.

Optimism Bias. Always seeing the glass as half full.

Blind Spot Bias. The bias that makes us think we don’t have as many biases as other people. You do.