Sensitivity to geometry in humans and other animals

Geometry can be defined as the mathematical formalization of space and of objects with spatial content (i.e., objects defined by angles, lengths, parallel lines, etc.). Amongst all theories of geometry, Euclidean geometry is considered the most intuitive of all for humans. The reason for this, it has been argued, is that humans and maybe other animals, evolved intuitions coherent with Euclidean principles that helped them better interact with the physical world. The physical world, however, is not Euclidean in all of its aspects. Objects' mass and their interaction with the gravitational field are not considered in Euclidean geometry, although objects' geometrical characteristics can determine their physical properties. This association between geometry and physics could influence how animal minds categorize geometrical objects. In this paper, I briefly review the evidence suggesting that humans and other animals are sensitive to differences in objects' geometrical characteristics. I further address the question whether Euclidean or physics intuitions underlie humans' and other animals' sensitivity to geometry and conclude that although physics intuitions might better explain how animals, including humans, categorize objects in terms of basic geometrical characteristics such as their shape, size, orientation, sense, and position, humans are special in their ability to reason about more abstract Euclidean concepts.