Coining a nickname for an entire generation has become something of a pastime for academics, journalists and marketers. This week, the cable network MTV joined the generational name game when it announced it had its own moniker for the millions of kids coming after millennials: the Founders. The idea that the people who make up a generation share certain characteristics—and thus should share a name—dates back to the mid-19th century, and most cohorts from even before that time have been given retroactive nicknames.