Racial subconscious, or racial memory, was a psychological theory which posited the existence of certain concepts and ideas which were inherent to a species, such as images representative of good and evil, and those which were considered terrifying.
In 2267, upon encountering a series of gothic imagery clearly meant to frighten humans, including witches, a black cat, and a dark castle, Commander Spock and Captain Kirk realized that the environment was being created based on the racial memories of humans as to what would scare them the most. (TOS: "Catspaw")