Psychologist Philip Zimbardo asks, “Why are boys struggling?” He shares some stats (lower graduation rates, greater worries about intimacy and relationships) and suggests a few reasons — and he asks for your help! Watch his talk, then take his short 10-question survey: http://on.ted.com/PZSurvey

Many of us have a social media presence — a virtual personality made up of status updates, tweets and connections, stored in the cloud. Adam Ostrow asks a big question: What happens to that personality after you’ve died? Could it … live on?

Khanna predicts that in the future, the real superpowers aren’t going to be countries. Instead, we’ll see the emergence of an entirely new structure: alliances comprised of universities, companies, non-profits, humanitarian agencies, sub-state units like city governments, and churches, all united around a common interest or vision.

Ron Gutman reviews a raft of studies about smiling, and reveals some surprising results. Did you know your smile can be a predictor of how long you’ll live — and that a simple smile has a measurable effect on your overall well-being