TED演講:語言如何改變?nèi)祟?3/5)

But in fact, it turns out that some time around 200,000 years ago, when our species first arose and acquired social learning, that this was really the beginning of our story, not the end of our story. Because our acquisition of social learning would create a social and evolutionary dilemma, the resolution of which, it's fair to say, would determine not only the future course of our psychology, but the future course of the entire world. And most importantly for this, it'll tell us why we have language. And the reason that dilemma arose is, it turns out, that social learning is visual theft. If I can learn by watching you, I can steal your best ideas, and I can benefit from your efforts, without having to put in the time and energy that you did into developing them. If I can watch which lure you use to catch a fish, or I can watch how you flake your hand axe to make it better, or if I follow you secretly to your mushroom patch, I can benefit from your knowledge and wisdom and skills, and maybe even catch that fish before you do. Social learning really is visual theft. And in any species that acquired it, it would behoove you to hide your best ideas, lest somebody steal them from you.