Hannah Fry: The mathematics of love

Why are babies cute? Why is cake sweet? Philosopher Dan Dennett has answers you wouldn't expect, as he shares evolution's counterintuitive reasoning on cute, sweet and sexy things (plus a new theory from Matthew Hurley on why jokes are funny).

Iranian-American comedian Maz Jobrani takes to the TEDxSummit stage in Doha, Qatar to take on serious issues in the Middle East -- like how many kisses to give when saying “Hi,” and what not to say on an American airplane.

Despite her best efforts, comedian Julia Sweeney is forced to tell a little white lie when her 8-year-old begins learning about frog reproduction -- and starts to ask some very smart questions.

When Colin Stokes’ 3-year-old son caught a glimpse of Star Wars, he was instantly obsessed. But what messages did he absorb from the sci-fi classic? Stokes asks for more movies that send positive messages to boys: that cooperation is heroic, and respecting women is as manly as defeating the villain…

Don't make people pay for music, says Amanda Palmer: Let them. In a passionate talk that begins in her days as a street performer (drop a dollar in the hat for the Eight-Foot Bride!), she examines the new relationship between artist and fan.