This intriguing puzzle, which even Harvard students got wrong, highlights how two modes of thinking, fast and slow, affect our decisions

Puzzle.  Three students, Peter, James, and Emma, went out to celebrate their exams. Peter bought five beer bottles, each costing £3,...

Puzzle.   You have a glass of milk and a bucket of water. First, take a spoonful of milk from the glass and add it to the bucket. Then,...