The origins of stigma lie not in ignorance or psychopathology but in Darwinian biology, said Griffith. Sociobiological systems involved in peer affiliation, social hierarchy, kin recognition, and social exchange operate through the dorsal anterior cingulate gyrus. That part of the brain detects information conflicts and prompts the prefrontal cortex to resolve them with reference to some quickly identifiable but potentially stigmatizing mark—race, gender, age, clothing, and so on.