Spatial reasoning in bilingual Mexico: Delimiting the influence of language

What is the relation been spatial language and cognition? Across speech communities, linguistic preferences for particular spatial frames of reference (FoR) predict nonlinguistic spatial reasoning strategies. This has been taken to imply a powerful influence of language on reasoning, but extra-linguistic factors may also matter. We present evidence from a bilingual community in Juchitán, Mexico, where the two languages contrast in how they encode space. In our spatial reasoning task, the population overall showed a mixed profile of FoR use. This naturally occurring variability provided a laboratory for asking, at a fine-grained level, what factors predict individuals’ spatial reasoning. Contrary to suggestions in the literature, we found no effects of language dominance or of the language used for the task. Instead, reliance on an egocentric strategy for the non-linguistic task was predicted by mastery of egocentric spatial vocabulary. These results delimit the influence of language on spatial reasoning.