One value of this study is its ability to tell us which physical cues people aren’t using to correctly match dogs with their human owners. It’s not about hairstyles, obesity, gender, height, or even eye color. As Nakajima points out, since all of the human models were Asian dog-owners, they all had similarly dark-colored eyes. Instead, it’s clearly something that’s being conveyed in the shared look about the eyes of dogs and their people. I’d add something romantic here about the eyes being the window to the soul, and therefore how this all makes sense given that our pets are of course—of course!—our soulmates, except I’m afraid that I don’t believe in souls of either the human or canine variety.

More likely is a logical scientific explanation about our apparently superhuman (or at least subconscious) ability to extract meaningful psychological cues from eyes. Nakajima is just as stumped as the rest of us about the underlying mechanism. And similar riddles exist, too. The psychologist Nicholas Rule and his colleagues, for instance, have found that naive judges can discern the sexual orientation of strangers from their eyes alone. How they’re going about this remains unclear, however, even to the judges themselves.