 Based on the theory of evolution, in order for a unique neural circuit to arise and be inherited, it must have provided some distinct survival or fitness advantage.It has been proposed that the ability to recognize faces is important for seeing another person as a friend or an enemy and that over the course of human history, as territorialism made other humans our biggest predators, this ability became crucial for survival.This circuit specializes over time, becoming more adept at distinguishing facial features among familiar people, race-groups, and age-groups.