Face-blind

Face-Blind:

What if you couldn't recognize faces?

It's an amazing faculty, actually: try this optical illusion, and you'll see that you can easily recognize the faces even at extremely low resolution.

A great deal of the human mind is biologically ordered to focus on this, which means that we are normally very good at it. It is normal for animals to be good at particularly important adaptive traits, and incapable of others that would seem to be as easy. "It is fairly easy to teach a dog to walk on its hind legs, but virtually impossible to teach it to yawn for a food reward. Cats can be taught to escape from boxes by pushing a sequence of buttons and pulling strings, but cannot learn to escape by scratching themselvs."*

That latter claim is kind of surprising, since you'd think you could use the ordinary kind of operant conditioning to train the cat. Apparently not!

Neither can you learn to recognize faces, apparently: you either can or cannot. You can train to recognize different kinds of faces: when I first started dealing with horses, I couldn't tell any two brownish horses apart; eventually, I could not only recognize but read the face of a horse, determining its sex and so on from the facial structure. You can do that with higher animals generally. In doing so, though, you're not generating a new mental faculty: you're only training one you have by nature.

* Stephen Budiansky, The Nature of Horses (New York: The Free Press, 1997), 158.