Today we know that feelings of pride and self-esteem are related to levels of the neurotransmitter serotonin in the brain, and that chimpanzees exhibit elevated levels of serotonin when they achieve alpha male status.13 It seems unlikely that there was ever a moment when behaviorally modern human beings did not compare themselves with one another or feel pride when they received social recognition. In this respect, Plato had a better understanding of human nature than Rousseau.
