A higher plane
Here’s a short geometry test: How many straight lines can be drawn connecting two points on a flat plane? If you make two angles on a triangle smaller, does the third get larger or smaller? If you split a square diagonally, are the two resulting triangles the same size or different? If the answers — for the record, one, larger, and the same — seem obvious, they should be. The questions are examples of the innate understanding of abstract geometry that all humans possess, even if they’ve never studied the subject. For researchers, however, the question is: Where does that knowledge come from? The answer, say Harvard scientists in Elizabeth Spelke’s Laboratory for Developmental Studies, may lie deep in our evolutionary history. Previous research has shown that young children and animals use geometric information in similar ways — to navigate environment and to recognize shapes. In a study published last month in the...