Why Your Brain Treats Strangers Like Threats

You're walking down a street at night. A figure steps out ahead — and before you've said a word, your body is already preparing for danger. But the stranger isn't the threat. The threat is the speed of your brain. In this video: why your brain judges people in less time than a blink, error management theory (Haselton & Buss), Tajfel's minimal groups, out-group homogeneity, the amygdala, the cross-race effect — and how real contact updates the model. Your brain was built to survive a world of small groups and rare outsiders. You're also the part that can watch it — and update it.