Simple math would demonstrate the truth of this, since 16 year old girls talk without pause from the moment they wake up until the moment they fall asleep (with the phone still at their ear) it only makes sense that they would lead the world in language innovation. This article discusses the English language only, but I'm sure it would prove true of all language, with the possible exception of Arabic, since those women are all so repressed.
The only thing I really don't get? Is how inflection has changed over the years? So every sentence? Sounds like a question? Even when it's not?