Well, I suppose you could argue either way, but I think it's a better question in the sense that humans are going to be used as a control group by most people t

Well, I suppose you could argue either way, but I think it's a better question in the sense that humans are going to be used as a control group by most people that follow pop science, and they're going to make assumptions that humans have this ability innately (I imagine development psychology has some degree of understanding for this already). Most discussion about this is going to be comparing the results to something else. Then there are questions like, could someone tell themselves apart from an identical twin without error?