From the field into the lab: causal approaches to the evolution of spatial language

Striking variation exists in preferences for specific spatial linguistic strategies among different speech communities. Increasing evidence now suggests that this might not simply be a result of neutral drift, but rather a form of linguistic adaptation to the local social, cultural, or physical environment. Recent studies indicate that different factors like topography, subsistence style, and bilingualism successfully predict the choice of spatial frames of reference (FoR) on linguistic and non-linguistic tasks. However, the exact causal relationships between these variables and the cultural evolutionary mechanisms behind the selection of one FoR strategy over another are still not fully understood. In this paper, we argue that to arrive at a more mechanistic and causal understanding of the cultural evolution of spatial language, observations from descriptive fieldwork should be combined with experimental and computational methods. In the framework we present, causal relationships between linguistic and non-linguistic variables (such as FoR choice and topography) can be isolated and systematically tested in order to shed light on how sociotopographic factors motivate the variation in spatial language we observe cross-linguistically. We discuss experimental results from behavioral studies and computer simulations that illustrate how this approach can deliver empirical findings that go beyond simple correlations.