Rap battles apparently can be traced to the Black American tradition of Dozens, a duel of insults that ends when the losing party is knocked sufficiently off balance to not be able to come up with a riposte. Though trying to psych people out with words is a recurring phenomenon: blues singers, for example, would compete to improvise the most outrageously filthy lyrics while performing live. (The original, unreleased version of Little Richard’s “Tutti Frutti” came from this tradition.)