Flexible frameworks for spatial thinking: Evidence from the Tsimane’ of Bolivia
 

The physical properties of space may be universal, but the way people conceptualize space is variable. In some groups, people tend to use egocentric space (e.g. left, right) to encode the locations of objects, while in other groups, people encode the same spatial scene using allocentric space (e.g. upriver, downriver). These different spatial frames of reference (FoRs) characterize the way people talk about spatial relations and the way they think about them, even when they are not using language. Although spatial language and spatial reasoning tend to covary across groups, the root causes of this variation are unclear. In two experiments with the Tsimane’, an indigenous Amazonian group, we found that individual participants’ FoR use in both linguistic and nonlinguistic tasks reversed across spatial axes, according to known differences in their discriminability: On the lateral axis, where egocentric (i.e. left-right) discrimination is difficult, participants’ spatial behavior and language was predominantly allocentric; on the sagittal axis, where egocentric (i.e. front-back) discrimination is relatively easy, they were predominantly egocentric. These findings challenge the longstanding assumption that each language group can be characterized by a predominant spatial frame of reference. Rather, both spatial memory and language can differ categorically across axes, even within the same individuals. We suggest that differences in spatial discrimination can explain (co)variation in spatial memory and language across cultures, between individuals, and over development.