Drift and Selection in Language Change
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 frequent words being replaced and regularizing less often. Two main hypotheses have been proposed to explain this: Frequent words change less because selection against innovation is stronger at higher frequencies, or because stochastic drift is stronger at lower frequencies. To test these hypotheses, we conducted experiments in which participants were tasked with learning a miniature language. Nouns were subjected to treatments that varied drift and selection. We then 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 observed in low-frequency nouns, adding to a growing body of evidence that drift may be a major driver of language change.