How Things Spread

Original broadcast date: March 4, 2016. What makes an idea, a brand, or a behavior catch fire? This hour, TED speakers explore the mysteries behind the many things we spread: laughter and sadness, imagination, viruses and viral ideas. Guests include neuroscientist Sophie Scott, entrepreneur Seth Godin, philanthropist Bill Gates, social scientist Nicholas Christakis, and historian Yuval Harari.