Common thinking traps (cognitive biases)

12 items · Ages 12+

12 biases with long research records. Each item names the researchers who first described or tested it. How strong each effect is varies with the situation, and researchers still debate the details; for the fundamental attribution error, for example, the effect is weaker in some cultures. Popular lists name hundreds of biases; this one keeps to well-studied ones.

Everyone's mind takes shortcuts, and most of the time they serve us well. These twelve are the places where the shortcuts lead us wrong in predictable ways. Knowing their names makes them easier to catch, in yourself first.

How to learn it

Encode each bias with your own example: after reading the everyday one, think of a time it happened to you and say it out loud. A personal story is far stickier than a definition. Chunk them by what they bend (judging numbers, looking ahead and back, beliefs and choices, judging people). Then practice retrieval in real life: name a bias when you see it in an ad or a story.

Encode make it vivid → Space bring it back on day 1, 3, 7, 21 → Retrieve pull it from your head. From the infographic Remember It on Purpose.

Common thinking traps (cognitive biases)

Bias	What it is	Everyday example	First described by
Anchoring	Leaning too hard on the first number you hear when you make an estimate.	A jacket tagged "was $120, now $60" feels like a deal, even if $60 is what it usually costs.	Tversky and Kahneman, 1974
Availability heuristic	Judging how common or likely something is by how easily examples come to mind.	After a news story about a plane crash, flying feels riskier than driving, though per mile driving is far more dangerous.	Tversky and Kahneman, 1973 and 1974
Gambler's fallacy	Believing that a chance event is "due" because it hasn't happened in a while.	After five heads in a row, feeling sure the next flip will be tails. A fair coin is still 50-50 every time.	Described by Tversky and Kahneman (1971) as part of the "law of small numbers"
Planning fallacy	Expecting your own task to take less time than it will, even when similar tasks ran long before.	Planning to finish a school project in one evening when the last three took a week each.	Kahneman and Tversky, 1979; Buehler, Griffin and Ross, 1994
Optimism bias	Believing good things are more likely, and bad things less likely, to happen to you than to other people.	Expecting your old car will keep running fine, though you know cars that age often break down.	Weinstein, 1980
Hindsight bias	Feeling, once you know how something turned out, that you knew it all along.	After the game: "I knew they would lose." Before it, you weren't sure at all.	Fischhoff, 1975
Confirmation bias	Noticing, believing and remembering the facts that fit what you already think, and passing over the ones that don't.	A fan who thinks a lucky shirt helps remembers the wins in that shirt and forgets the losses.	Wason, 1960; reviewed by Nickerson, 1998
Framing effect	Choosing differently when the same facts are worded as a gain or as a loss.	Ground beef labeled "90% lean" sounds better than "10% fat," though it is the same meat.	Tversky and Kahneman, 1981
Loss aversion	Feeling a loss more strongly than a gain of the same size.	Losing a $10 bill stings more than finding one feels good.	Kahneman and Tversky, 1979 (prospect theory)
Status quo bias	Preferring to keep things as they are, even when a change would serve you better.	Staying on the same phone plan for years without checking whether a cheaper one fits.	Samuelson and Zeckhauser, 1988
Halo effect	Letting one good impression of a person color how you judge their other, unrelated qualities.	Assuming a friendly, well-dressed stranger must also be smart and honest.	Thorndike, 1920
Fundamental attribution error	Explaining other people's actions by their character while overlooking their situation.	Deciding the driver who cut you off is rude, when they might be rushing to the hospital.	Named by Ross, 1977; Jones and Harris, 1967

Common thinking traps (cognitive biases): practice sheet

Name: ______________________ Date: ____________ Score: ____ / 12

Bias	What it is	Everyday example	First described by
	Leaning too hard on the first number you hear when you make an estimate.
	Judging how common or likely something is by how easily examples come to mind.
	Believing that a chance event is "due" because it hasn't happened in a while.
	Expecting your own task to take less time than it will, even when similar tasks ran long before.
	Believing good things are more likely, and bad things less likely, to happen to you than to other people.
	Feeling, once you know how something turned out, that you knew it all along.
	Noticing, believing and remembering the facts that fit what you already think, and passing over the ones that don't.
	Choosing differently when the same facts are worded as a gain or as a loss.
	Feeling a loss more strongly than a gain of the same size.
	Preferring to keep things as they are, even when a change would serve you better.
	Letting one good impression of a person color how you judge their other, unrelated qualities.
	Explaining other people's actions by their character while overlooking their situation.

Write from memory, then check against the study sheet. Mark the misses and review those first next time. · teddyrookbook.com/memory/challenges/cognitive-biases/

Sources

Checked October 30, 2026. Progress is kept on this device only (per learner). More lists: all memory challenges · memory games.