Vol. 22, No. 2
Cultural evolution of combinatorial structure in ongoing artificial speech learning experiments
1 University of Amsterdam
2 University of California San Diego
3 University of Edinburgh
The Yupno of Papua New Guinea make extensive use of topographic terms—such as uphill and downhill—for conceptualizing spatial relations (Wassmann, 1994). Given the ubiquity of topographic distinctions in everyday Yupno language, an interesting question is whether such contrasts are also used when topographic landmarks are not available, such as within traditional houses. Yupno houses have flat, oval floor plans, a central fireplace, and few, if any, windows. Yet in natural conversation topographic terms are still widely used indoors. We conducted a field experiment to test whether the use of these terms indoors followed a pattern, and, if so, whether the pattern was motivated by the orientation of the houses in macro-space or, instead, by the houses' own intrinsic asymmetries. 16 Yupno adults (8 men, 8 women) participated in a reference disambiguation task in which they pointed to or grabbed real-word objects in response to pre-recorded imperative sentences (e.g. "Point to the uphill orange"). The auditory stimuli consisted of four topographic target words (two contrasting pairs). Two different traditional houses were used between participants: one faced a downhill direction in the macro-scale topography outside the house; the other faced an uphill direction. Results demonstrate that in both houses participants systematically evoked a micro-world construal of absolute, topographic terms: objects toward the door were construed as downhill, while objects away from the door were construed as uphill, irrespective of the topographic conditions outside. Our results are best explained by a systematic conceptual mapping of an asymmetry of the macro-world (downhill, uphill) onto an asymmetry of the micro-world (toward the door, away from the door). We discuss different factors that serve to support this construal, as well as some implications for the taxonomy of spatial frames of reference.