Overview: Chris Packham explores the evolution of the great ape's brain to reveal how different parts have been adapted over time by its anatomy, ingenuity and sociability, culminating in one of the most complex brains on the planet. Chris examines how the ability to use two hands asymmetrically sets the great ape apart from other tool-using animals and how social living is linked to the evolution of the amygdala in both humans and our ape cousins. New research reveals how bonobos' peace-loving reputation may have developed through a similar domestication process to that undergone by our pet dogs.