Ted Radio Hour: Maslow

Humans need food, sleep, safety, love, purpose. Psychologist Abraham Maslow ordered our needs into a hierarchy. On this week's show, TED speakers explore that spectrum of need, from primal to profound

What do we know about one of our most basic needs: sleep? Not a lot, says circadian neuroscientist Russell Foster. We know we need to do it to stay alive, but much about it remains a mystery. 

Computer security expert Bruce Schneier says there's a big difference between feeling secure and being secure. He explains why we worry about unlikely dangers while ignoring more probable risks. 

Journalist Sebastian Junger was embedded with soldiers during the war in Afghanistan. He says many veterans miss war because it fulfills a deep human need to belong to a trusted group.

Caroline Casey didn't know she was legally blind until she was 17 years old. The shocking news tested her confidence and self-esteem in ways that shaped the rest of her life. 

Psychologist Mihaly Csikszentmihalyi says we can achieve one of the most elusive needs---self-actualization--by finding a state of “flow,” in our work or our hobbies.