“…Research on animal communicative behavior has long acknowledged the utility of distinguishing different frames for different types of causal process, invoking ethologist Niko Tinbergen's “four questions”: (1) the mechanism of a behavior, (2) the fitness value of the behavior, (3) its evolutionary foundation, and (4) its emergence in the lifespan (Tinbergen, 1963; cf., Bateson & Laland, 2013). Linguists have implicitly invoked a similar range of frames for examining dynamic processes in language 4 : the microgenetic frame focuses on the moment‐by‐moment processing of language, whether in production or comprehension (see Cutler, 2005, 2012; Hagoort, 2019; Levelt, 1989); the ontogenetic frame focuses on development in the lifespan, especially the process of first‐language acquisition in the first few years of life, but also covering any developmental phase including second‐language learning in adulthood (Behrens, 2021; Bowerman & Levinson, 2001; Clark, 2003; Klein, 1986; Saville‐Troike & Barto, 2017; Tomasello, 2003); the phylogenetic frame focuses on the processes by which our species evolved such that we (and only we) are capable of acquiring language (Fitch, 2010; Hurford, 2007, 2012); and the diachronic frame refers to changes in a language that occur over historical time (and that imply population‐level processes): in cognitive approaches to linguistics, work in the diachronic frame has primarily concerned semantic change, either in the lexicon (Blank & Koch, 1999), in the morphosyntax (Harris & Campbell, 1995), or in the link between the two (i.e., in research on grammaticalization; see Nikiforidou, 1991, Traugott & Heine, 1991, Sweetser, 1990, Hopper & Traugott, 1993, Traugott & Dasher, 2002, Heine, 2002).…”