▪ Abstract Using Australian languages as examples, cultural selection is shown to shape linguistic structure through invisible hand processes that pattern the unintended outcomes (structures in the system of shared linguistic norms) of intentional actions (particular utterances by individual agents). Examples of the emergence of culturally patterned structure through use are drawn from various levels: the semantics of the lexicon, grammaticalized kin-related categories, and culture-specific organizations of sociolinguistic diversity, such as moiety lects, “mother-in-law” registers, and triangular kin terms. These phenomena result from a complex of diachronic processes that adapt linguistic structures to culture-specific concepts and practices, such as ritualization and phonetic reduction of frequently used sequences, the input of shared cultural knowledge into pragmatic interpretation, semanticization of originally context-dependent inferences, and the input of linguistic ideologies into the systematization of lectal variants. Some of these processes, such as the emergence of subsection terminology and moiety lects, operate over speech communities that transcend any single language and can only be explained if the relevant processes take the multilingual speech community as their domain of operation. Taken together, the cases considered here provide strong evidence against nativist assumptions that see linguistic structures simply as instantiations of biologically given “mentalese” concepts already present in the mind of every child and give evidence in favor of a view that sees individual language structures as also conditioned by historical processes, of which functional adaptation of various kinds is most important. They also illustrate how, in the domain of language, stable socially shared structures can emerge from the summed effects of many communicative micro-events by individual agents.