"All ideas have a genealogy," says David Eagleman. A writer, neuroscientist, and adjunct professor at Stanford University, he's definitely clued in to what makes ideas click. He posits that the brain craves something new so much that if you give someone the same thing over and over that after a certain amount of time you'll begin to see diminished returns in excitement. But sometimes "new" isn't necessarily new at all. He points out that although the iPhone is a revolutionary product it bears heavy similarity to an invention from IBM... from two decades ago. New ideas tend to be built upon similar ones, David Eagleman says, because "what we’re doing is building on the foundations of what has come before us." See Review of David's new book is The Runaway Species: How Human Creativity Remakes the World.