And when people’s firmly held beliefs are challenged—particularly those tied to their sense of self—the brain reacts the same way it would to a physical threat, ready to defend those beliefs as if they were part of the body. Adrenaline courses through the bloodstream, the heart races, and the prefrontal cortex, the brain’s logic center, is functionally compromised. It can make people impulsive and irrational. Cruel, even.
