It's no secret that African Americans are a powerful force on Twitter, with higher rates of use and black-culture-related topics frequently topping the trending topic list. And there's much more than anecdotal evidence of blacks taking the lead more generally when it comes to what the rest of the country eventually embraces and deems "cool."
So we're not shocked by a recent study  by computer scientist Jacob Eisenstein of the Georgia Institute of Technology in Atlanta and his colleagues, which found that much of the shorthand used on the social networking site evolves in cities with large African-American populations before spreading out more widely. From BBC News: 
Other neologisms have different life stories. Spelling bro, slang for brother (male friend or peer) as bruh began in the southeastern US (where it reflects the local pronunciation) before finally jumping to southern California. The emoticon "-__-" (denoting mild annoyance) began in New York and Florida before colonising both coasts and gradually reaching Arizona and Texas.
Who cares? Well, the question of how language changes and evolves has occupied linguistic anthropologists for several decades. What determines whether an innovation will propagate throughout a culture, remain just a local variant, or be stillborn? Such questions decide the grain and texture of all our languages -- why we might tweet "I'm bored af" rather than "I'm bored, forsooth".
There are plenty of ideas about how this happens. One suggestion is that innovations spread by simple diffusion from person to person, like a spreading ink blot. Another idea is that bigger population centres exert a stronger attraction on neologisms, so that they go first to large cities by a kind of gravitational pull. Or maybe culture and demography matters more than geographical proximity: words might spread initially within some minority groups while being invisible to the majority.
It's great to be able to take credit for "bruh" and "-__-," but to us, the research raises larger questions about how this apparent influence and power to define dialogue could be used for something more substantial than slang.