"Understanding what chimpanzees are like has made me realize that we humans are not so different from other animals as we used to think. What makes us most different is that we are far more clever than even the cleverest chimp, and we have words. We have a spoken language. We can tell stories about what happened a week or a year or a decade ago. We can plan for the future, and we can discuss things - one person's idea can grow and change as other people contribute their ideas. Great ideas become greater, problems are solved."