Biases Are Features

Your brain runs on heuristics, mental shortcuts that trade accuracy for speed. They usually help, but they can misfire. The availability shortcut makes vivid events feel more likely than they are. A plane crash dominates the news, so flying can feel scary even though everyday car travel is statistically far more dangerous.

For our ancestors, that bias paid off. Overreacting to a threat was cheap; underreacting could be fatal. Bolting from a harmless shadow cost a few seconds, while ignoring a real predator cost everything. So the brain was tuned for survival, not accuracy, and it still leans that way today.