“When I ask my audiences this question, they generally say it’s just something they heard but they have no idea where or from who. Yet they are very confident that this is true. That should be proof enough that the way we form beliefs is pretty goofy.” – Annie Duke
The quote above pertains to the belief that male baldness is passed down from the maternal grandfather. Turns out, your Mom’s Dad is just “a variable” in explaining baldness, not “the variable”. People’s belief in this is based on hearsay, not objective evidence of a meaningful sample size. The point Duke is making in “Thinking in Bets” is that we form our beliefs rather indiscriminately.