  This paper measures the stability of cross-linguistic register variation. A
register is a variety of a language that is associated with extra-linguistic
context. The relationship between a register and its context is functional: the
linguistic features that make up a register are motivated by the needs and
constraints of the communicative situation. This view hypothesizes that
register should be universal, so that we expect a stable relationship between
the extra-linguistic context that defines a register and the sets of linguistic
features which the register contains. In this paper, the universality and
robustness of register variation is tested by comparing variation within vs.
between register-specific corpora in 60 languages using corpora produced in
comparable communicative situations: tweets and Wikipedia articles. Our
findings confirm the prediction that register variation is, in fact, universal.
