Humans possess a higher-level, universal capacity to grasp abstract geometrical concepts, a study finds. Humans are unique among primates in their ability to create formal symbolic systems that capture regularities in the external world. Mathias Sablé-Meyer, Stanislas Dehaene, and colleagues provide evidence that humans, but not baboons, use a symbolic strategy to process the regularities of geometric shapes, regardless of age, culture, or education. The authors generated 11 quadrilaterals, or four-sided shapes, that varied in their number of geometric regularities, including parallel lines, equal angles, equal sides, and right angles. During each trial, 605 adults were asked to identify a deviant among six shapes presented. Both response times and error rates decreased as the total number of geometric regularities rose. Similar results were observed with 28 kindergartners, 156 first-graders, and 22 Himba adults, who were recruited in small villages in Namibia and did not attend a single year of school. By contrast, 11 baboons that were extensively trained on the task and reached a similar accuracy as kindergartners were not sensitive to geometric regularities. The performance of baboons was captured by a simple perceptual model, whereas human behavior was well predicted by a model that assumes an additional level of symbolic processing of geometric features. The findings reveal a signature of human singularity in grasping abstract geometrical concepts and challenge nonsymbolic models of human shape perception, according to the authors.
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Article #20-23123:
"Sensitivity to geometric shape regularity in humans and baboons: A putative signature of human singularity," by Mathias Sablé-Meyer et al.
MEDIA CONTACTS:
Mathias Sablé-Meyer, Université Paris-Saclay, Saclay, FRANCE;
tel: +33 6 28 32 60 01;
email: <mathias.sable-meyer@ens-cachan.fr>;
Stanislas Dehaene,
Université Paris-Saclay, Saclay, FRANCE;
email: <stanislas.dehaene@cea.fr>