A bat and a ball cost $1.10 in total. The bat costs $1 more than the ball. How much is the ball? The intuitive answer: 10 cents. The right answer: 5 cents. In Shane Frederick's 2005 study, more than half of students at Harvard, MIT and Princeton got it wrong, and over 80% at less selective universities. Intuition answers before arithmetic gets a chance to check.
Remembering is not replaying a recording — it is rebuilding. Each time you recall a memory, it becomes temporarily malleable and can be altered before being stored again. That is why two people can sincerely remember the same event… differently.
In 2003, Johnson and Goldstein compared European countries. Where you must tick a box to become a donor, consent rates ranged from 4% to 28%. Where you're a donor by default unless you opt out, they topped 85%. People aren't more generous on one side; most simply stick with whatever option was chosen for them.