What Makes Us Human?

Scientists have struggled for centuries to pinpoint the qualities that separate human beings from the millions of other animal species that have evolved on this planet. David Pogue explores the traits we once thought were uniquely ours—language, tool-making, even laughter—to uncover their evolutionary roots. He'll trace some of the crucial steps that transformed cave men to accountants, and find out if any of his own DNA came from a Neanderthal ancestor.