Dan’s goal, taken from his mentor Richard Zeckhauser, is to get students to think probabilistically about the world. This means engaging with the cha… - David Franklin

It turns out that you only need 23 people for it to be more likely to find a shared birthday than not.

The students are asked to rate their level of surprise on a five-point scale from ‘not surprised at all’ to ‘beyond shock’. Many describe feelings of total shock and numbness: a large majority indicate some level of surprise. He asks them: “Why were you surprised?

After pausing, the student continues: “There’s also an element of believing something because you want it to happen.” This betrays a second bias in which we believe what we want to be true. This is a form of confirmation bias, which exacerbates the distorting effect of availability bias. We seek out information that confirms our existing beliefs or desires, and ignore information that refutes them.