(video, 16 min)
Matt Ridley, the author of The Rational Optimist and many other great books, argues that humanity's collective brain created through trading and exchange of ideas is what makes us different from other species.
This simple idea is much deeper than it may appear at first glance.
According to Matt Ridley, over the course of a million+ years, humans started producing more tools that cannot be made by any single person, but require collective intelligence of a (large) number of people. For example, take two objects of similar size: a hand axe, made essentially without additional innovations for 1 million years, and a computer mouse.