Mental model
20 cards from across every topic, each citing a source. Tap one to open it in the feed.
- 'A language is a dialect with an army and navy.'
Popularised in 1945 by Yiddish scholar Max Weinreich, the line sums it up: whether something is called a language or a …
- 'The word really means …' is usually a fallacy.
The etymological fallacy: believing a word's origin fixes its true meaning. 'Decimate' meant killing every tenth Roman …
- 20 percent of your work delivers 80 percent of the result.
Vilfredo Pareto noticed in 1896 that 20 percent of Italians owned 80 percent of the land. The pattern shows up …
- A 99 percent accurate test, and you're still probably healthy.
A disease affects 1 in 10,000. The test detects it 99 percent of the time and gives 1 percent false alarms in healthy …
- A look-alike word is a hypothesis, not a translation.
Spanish and English share thousands of cognates: nación/nation, animal/animal, importante/important. That speeds up …
- And then what? The question most decision-makers skip.
First-order thinking sees the direct effect: a bounty on rats reduces rats. Second-order thinking asks "And then?": in …
- Does your language shape your thinking? Yes, but quietly.
The strong Sapir-Whorf claim, that language determines what you can think, is refuted. The weak version holds: language …
- Don't ask how to win. Ask how to lose for sure.
Inversion flips the problem. Instead of "How do I become productive?" you ask "How do I guarantee a ruined day?": phone …
- Good enough beats perfect, and makes you happier.
Herbert Simon coined the term satisficing in 1956: instead of hunting for the best option, you set a threshold in …
- Imagine the project has failed. Now explain why.
Gary Klein developed the pre-mortem: before starting, the team imagines a year has passed and the project has failed …
- Nobody ignored you. They forgot your message.
Hanlon's razor: never attribute to malice that which is adequately explained by stupidity. The unanswered email, the …
- Odysseus had himself tied up because he didn't trust himself.
To hear the Sirens' song without drowning, Odysseus had himself bound to the mast and ordered his crew not to release …
- Once a metric becomes the target, it stops working.
Goodhart's law: when a measure becomes a target, it ceases to be a good measure. Pay programmers per line of code and …
- Six sliders for comparing cultures.
From 1967, Geert Hofstede analysed surveys of IBM employees in 50 countries and found dimensions on which cultures …
- The explanation with the fewest assumptions usually wins.
William of Ockham stated in the 14th century that one shouldn't multiply assumptions beyond necessity. If your car …
- The map is not the territory, and your model isn't the world.
Alfred Korzybski put it in 1931: the map is not the territory. Every map leaves things out, or it would be as large as …
- The money's gone whether or not you finish the film.
Sunk costs are paid and won't come back: the 12-euro cinema ticket, three years in the wrong degree. Rationally, only …
- Why 'yes' in Japan sometimes means 'no'.
Anthropologist Edward T. Hall in 1976 sorted cultures by how much they rely on context. In low-context cultures such as …
- Why the millionth unit costs almost nothing and the first a fortune.
A chip factory costs several billion euros whether it makes a thousand chips or a billion. Economies of scale: fixed …
- Your portfolio changes its risk on its own, without you doing anything.
Say you chose 60% stocks and 40% bonds. Stocks rise 25% over a year while bonds stay flat: you now hold 65% stocks …