Spontaneous Understanding of Geometry

Mundurukú children and adults were asked, in their language, to point to the one “weird” or “ugly” box from each series of six boxes. Forty five of these experiments are described in the paper, in Figure 1. The shapes above test the idea of a straight line, a principal in Euclidian geometry. Ninety three percent of the Mundurukú participants got this right. Using the same protocol described above, this series of shapes in boxes tests the viewers ability to pick out the box in which the white circle is not in the center of the black circle. This concept of geometry is considered a “metric property.” Sixty eight percent of the Mundurukú participants got this right. Picking out the “weird” image from the series of shapes above requires a mental geometrical transformation. Forty three percent of the Mundurukú participants got this right. [Imagse © Science]

In a series of experiments reported in Science, children and adults from an isolated Amazonian indigene group, the Mundurukú, showed that they understood and could use a variety of concepts of geometry even though they do not have words for these concepts.

This study brings new evidence to bear on a much-discussed and debated question amongst psychologist and philosophers alike: how does language influence thought? The work suggests that conceptual principles of geometry are inherently present in the minds of the Mundurukú, even though they lack the words for geometrical terms and concepts.

Both Mundurukú children and adults grasped ideas such as parallel lines and right-angled triangles and were able to use geometric relationships diagrammed on paper to locate hidden objects as well as American children, though somewhat less so than educated American adults. The results provide evidence for geometrical intuitions in the absence of schooling, experience with graphic symbols or maps, or a rich language of geometrical terms.

19 January 2006