Greed is good. War is inevitable. Whether in political theory or popular culture, human nature is often portrayed as selfish and power hungry. UC Berkeley psychologist Dacher Keltner challenges this notion of human nature and seeks to better understand why we evolved pro-social emotions like empathy, compassion and gratitude.

We've all heard the phrase 'survival of the fittest', born from the Darwinian theory of natural selection. Keltner adds nuance to this concept by delving deeper into Darwin's idea that sympathy is one of the strongest human instincts — sometimes stronger than self-interest.

FEATURING: Dacher Keltner, professor of psychology and founding faculty director of the Greater Good Science Center at UC Berkeley