Stress. It makes your heart pound, your breathing quicken and your forehead sweat. But while stress has been made into a public health enemy, new research suggests that stress may only be bad for you if you believe that to be the case. Psychologist Kelly McGonigal urges us to see stress as a positive, and introduces us to an unsung mechanism for stress reduction: reaching out to others.

Dan Gilbert, author of "Stumbling on Happiness," challenges the idea that we'll be miserable if we don't get what we want. Our "psychological immune system" lets us feel truly happy even when things don't go as planned.

At TED U, Gever Tulley, founder of the Tinkering School, spells out 5 dangerous things you should let your kids do -- and why a little danger is good for both kids and grownups.

Cognitive scientist Donald Hoffman is trying to answer a big question: Do we experience the world as it really is ... or as we need it to be? In this ever so slightly mind-blowing talk, he ponders how our minds construct reality for us.

Right now, billions of neurons in your brain are working together to generate a conscious experience -- and not just any conscious experience, your experience of the world around you and of yourself within it. How does this happen? According to neuroscientist Anil Seth, we're all hallucinating all the time; when we agree about our hallucinations, we call it "reality." Join Seth for a delightfully disorienting talk that may leave you questioning the very nature of your existence.