A new experiment: Does AI really know cats or dogs -- or anything?

Most humans can recognize a cat or dog at an early age. Asked to articulate how they know if an animal is a cat or a dog, an adult might fumble for an explanation by describing experience, something such as "cats appraise you in a distant fashion, but dogs try to jump up on you and lick your face." We don't really articulate what we know, in other words. The signature achievement of artificial intelligence in the past two decades is classifying pictures of cats and dogs, among other things, by assigning them to categories. But AI programs never explain how they "know" what they supposedly "know."