Brief at the risk of being misunderstood: consolidating population- and individual-level tendencies

Abstract

Communicative pressures can give rise to regular patterns of language use. These patterns, in turn, can come to shape a language’s structure over time. In a recent study, Kanwal et al. (Cognition, 165:45–52, 2017) investigate whether an interaction of such pressures may underlie the cross-linguistic tendency of frequent forms to be shorter. Using a miniature artificial language, they show that speakers follow this tendency if pressured for brevity and accuracy. In this study, we use probabilistic models of varying complexity to shed light on the individual-level factors behind this trend. We find that a hierarchical model that accommodates for subjects’ heterogeneous beliefs about object frequencies best explains the data. At the population level, this model predicts an association of short forms with frequent meanings, in line with past research. At the individual level, however, it reveals a number of patterns that systematically deviate from this trend. On the one hand, these findings support the hypothesis that individual-level pressures may underlie natural languages’ relationship between frequency and brevity. On the other, by characterizing the individual-level dynamics on which this relationship rests, they highlight the importance of consolidating multiple strata of analysis and of understanding where and why they might diverge.