Is it only humans that count from left to right?
How does one answer the question on whether animals, other than humans, count from left to right like us? The authors of this paper [1] come up with an ingenious way to test this. Here is their approach. Animals could be trained to interact with an object at a particular position in a long series of such identical objects for a reward. During training the series of objects need to be placed in such a way that counting from left to right or right to left requires interacting with the same object. This can be achieved by placing the series of objects sagittally - such that only one object (closest) is facing the animal and the rest are positioned along a single long column till the farthest object. However, while testing the animal for directional preference, the series of objects need to be placed coronally - such that all objects are arranged facing the animal in a single row. Here counting from right to left or left to right results in choosing an object at different positions. This