How can humans be so compassionate and altruistic and also so brutal and violent? To understand why we do what we do, neuroscientist Robert Sapolsky shares his cutting edge research into the biology that drives our worst and best behaviors.

“Now, to me, the single most important point about all of this is that every bit of biology I have mentioned here can change in different circumstances. Brains change. Neurons grow new processes. Circuits disconnect. Everything in the brain changes, and it could happen in years, just hours or in seconds“.