Puzzles
People will bet on a coin they trust over odds they simply can't calculate
You're offered two urns to bet on. Urn A has exactly 50 red balls and 50 black balls. Urn B has 100 red and black balls in a completely unknown ratio. You must bet on a colour being drawn from one urn — does it matter which urn you choose?
Reveal the answer
Standard probability theory says no: Urn B's unknown 50/50 average expectation is identical to Urn A's known 50/50 split. Yet most people strongly prefer betting on Urn A, whichever colour they choose. Daniel Ellsberg used this in 1961 to show people aren't just averse to risk — they're separately averse to ambiguity, and not knowing the odds at all feels worse than knowing you've got an even chance.
— Daniel Ellsberg, Risk, Ambiguity, and the Savage Axioms — Quarterly Journal of Economics, 1961