Some of you may have seen Gabe, the border collie who can identify over 1,000 objects by name, from TV. A new study with Gabe shows that he identifies objects not by their shape but by size, and then texture. He's considered as bright as a two year old. On TV, I've seen Gabe infer the name of a new unidentified toy. He's quite impressive.
This surprising difference object comprehension is difficult for me to take in. I can imagine primates identifying fruit by shape first, then texture, then size. Wouldn't wild dogs need to distinguish prey by their shape first too? Surely a 20 pound skunk is very different from a 20 pound rabbit. Animals change size all of the time. So how does this compute? Do they depend on smell to distinguish species?
It would explain how species can adopt young from other species.
Previous studies have shown that humans between the ages of two to three typically learn to associate words with the shapes of objects, rather than their size or texture. For example, toddlers who learn what a 'ball' is and are then presented other objects with similar shapes, sizes or textures will identify a similarly-shaped object as 'ball', rather than one of the same size or texture.
Gable learned to associate the name of an object with its size, identifying other objects of similar size by the same name. After a longer period of exposure to both a name and an object, the dog learned to associate a word to other objects of similar textures, but not to objects of similar shape. According to the authors, these results suggest that dogs (or at least Gable) process and associate words with objects in qualitatively different ways than humans do.
"Where shape matters for us, size or texture matters more for your dog. This study shows for the first time that there is a qualitative difference in word comprehension in the dog compared to word comprehension in humans."