Over half a century ago, George Zipf observed that more frequent words tend to be older. Corpus studies since then have confirmed this pattern, with more frequent words being replaced and regularized less often than less frequent words. Two main hypotheses have been proposed to explain this: that frequent words change less because selection against innovation is stronger at higher frequencies, or that they change less because stochastic drift is stronger at lower frequencies. Here, we report the first experimental test (...) of these hypotheses. Participants were tasked with learning a miniature language consisting of two nouns and two plural markers. Nouns occurred at different frequencies and were subjected to treatments that varied drift and selection. Using a model that accounts for participant heterogeneity, we measured the rate of noun regularization, the strength of selection, and the strength of drift in participant responses. Results suggest that drift alone is sufficient to generate the elevated rate of regularization we observed in low‐frequency nouns, adding to a growing body of evidence that drift may be a major driver of language change. (shrink)

The acceptability of sentences in natural language is constrained not only grammaticality, but also by the relationship between what is being conveyed and such factors as context and the beliefs of interlocutors. In many languages the critical element in a sentence (its focus) must be given grammatical prominence. There are different accounts of the nature of focus marking. Some researchers treat it as the grammatical realization of a potentially arbitrary feature of universal grammar and do not provide an explicit account (...) of its origins; others have argued, however, that focus marking is a (grammaticalized) functional solution to the problem of efficiently transmitting information via a noisy channel. By adding redundancy to highlight critical elements in particular, focus protects key parts of the message from noise. If this information‐theoretic account is true, then we should expect focus‐like behavior to emerge even in non‐linguistic communication systems given sufficient noise and pressures for efficiency. We tested this in an experiment in which participants played a simple communication game in which they had to click cells on a grid to communicate one of two line figures drawn across the grid. We manipulated the noise, available time, and required effort, and measured patterns of redundancy. Because the lines in many cases overlapped, meaning that only some parts of each line could be used to distinguish it from the other, we were able to compare the extent to which effort was expended on adding redundancy to critical (non‐overlapping) and non‐critical (overlapping) parts of the message. The results supported the information‐theoretic account of focus and shed light on the emergence of information structure in language. (shrink)

We investigated the emergence of sociolinguistic indexicality using an artificial-language-learning paradigm. Sociolinguistic indexicality involves the association of linguistic variants with nonlinguistic social or contextual features. Any linguistic variant can acquire “constellations” of such indexical meanings, though they also exhibit an ordering, with first-order indices associated with particular speaker groups and higher-order indices targeting stereotypical attributes of those speakers. Much natural-language research has been conducted on this phenomenon, but little experimental work has focused on how indexicality emerges. Here, we present three (...) miniature artificial-language experiments designed to break ground on this question. Results show ready formation of first-order indexicality based on co-occurrence alone, with higher-order indexicality emerging as a result of extension to new speaker groups, modulated by the perceived practical importance of the indexed social feature. (shrink)

How do speakers learn the social meaning of different linguistic variants, and what factors influence how likely a particular social–linguistic association is to be learned? It has been argued that the social meaning of more salient variants should be learned faster, and that learners' pre‐existing experience of a variant will influence its salience. In this paper, we report two artificial‐language‐learning experiments investigating this. Each experiment involved two language‐learning stages followed by a test. The first stage introduced the artificial language and (...) trained participants in it, while the second stage added a simple social context using images of cartoon aliens. The first learning stage was intended to establish participants' experience with the artificial language in general and with the distribution of linguistic variants in particular. The second stage, in which linguistic stimuli were accompanied by images of particular aliens, was intended to simulate the acquisition of linguistic variants in a social context. In our first experiment, we manipulated whether a particular linguistic variant, associated with one species of alien in the second learning phase, had been encountered in the first learning phase. In the second experiment, we manipulated whether the variant had been encountered in the same grammatical context. In both cases we predicted that the unexpectedness of a new variant or a new grammatical context for an old variant would increase the variant's salience and facilitate the learning of its social meaning. This is what we found, although in the second experiment, the effect was driven by better learners. Our results suggest that unexpectedness increases the salience of variants and makes their social distribution easier to learn, deepening our understanding of the role of individual language experience in the acquisition of sociolinguistic meaning. (shrink)