Back in the Middle Ages, there was a pseudo-science called physiognomy which maintained that you could tell what a person's morality was like based on his outward physical appearance. This is taken to extremes in Chaucer's The Canterbury Tales, where the pilgrims' character flaws are revealed through their physical descriptions (leading some experts to conclude, for example, that the Pardoner is gay).

A post at Boing Boing discusses how Roald Dahl, author of Charlie and the Chocolate Factory, among dozens of novels and short stories for both children and adults, makes use of physiognomy:

In many children's books--contrary to what parents tell their children about the meaning of appearances--physical ugliness signifies its moral equivalent. Dahl takes this to an extreme, describing his villains' repulsive attributes with brio: Mr. Hazell's "great, glistening, beery face . . . as pink as a ham," in "Danny, the Champion of the World" (1975); Aunt Sponge's resemblance to "a great white soggy overboiled cabbage"; the "grizzly old grunion of a grandma" in "George's Marvelous Medicine" (1981)--the one Dahl book I find irredeemably sour--who has "a small puckered-up mouth, like a dog's bottom." Dahl shared with George Orwell an acute sense of why small children often see adults as unsightly or intimidating. "Part of the reason for the ugliness of adults, in a child's eyes, is that the child is usually looking upward, and few faces are at their best when seen from below," Orwell wrote. Dahl once said that adults should get down on their knees for a week, in order to remember what it's like to live in a world in which the people with all the power literally loom over you.

But this may be a British thing.

I will now reveal that, for the last week, I have been reading Harry Potter. Last Saturday, when children all over the English-speaking world were starting Harry Potter and the Half-Blood Prince, I was just beginning Harry Potter and the Sorcerer's Stone. As of now, I am halfway through the fourth book, Harry Potter and the Goblet of Fire. And let me tell you, J.K. Rowling makes just as much use of physiognomy as Dahl or Chaucer ever did.

Take Harry Potter's loathsome adopted parents, the Dursleys. Mr. Dursley, Harry's uncle, is a very fat man, described as having small, squinty eyes and no neck. Their son, Dudley, Harry's cousin, is equally fat. Harry's aunt, Mrs. Dursley, is actually quite skinny. What does this all mean? In the world of Harry Potter, a physical description or a name goes a long way in saying how J.K. Rowling feels about you. Uncle Vernon Dursley and Dudley Dursley are both very fat and Uncle Vernon is morbidly concerned with normality. He hates anything to do with magic and lives in constant, horrible fear that someone will find out that his nephew is . . . not normal! As such, the Dursleys go to great lengths to be hyper-normal, so much so that they ignore anything interesting in the world. Take a look at the name "Dudley Dursley." There's a reason why it sounds a lot like the word "dud": Dudley is a dud in the sense that he is "unsatisfactory or worthless." This is manifested in his name as well as his physical characteristics. Torpidity in body means torpidity of the mind; that is, Dudley is lazy physically as well as mentally. He does not exercise his mind or his body, and he fills both with crap: sweets and cakes for his body, and television, computer games, and Playstation for his mind. He has no interest in learning anything new or interesting or bettering himself as a person.

Dahl did the same thing in Charlie and the Chocolate Factory, using physical descriptions to indicate inner vices. He also masterfully used onamotapoetic names for his characters. Does the name "Augustus Gloop" sound appealing? What does "gloop" sound like? Whatever it is, it can't be good. Rowling does the same thing. What does "Slytherin" sound like? Obviously, it sounds like a snake, which in fact is the symbol of the clearly evil Slytherin house. How about "Griffyndor"? Sounds like a griffyn (gryphon or griffen), an animal that is half lion and half eagle. That's one freaking noble animal! Rowling wants us to like Griffyndor and despise Slytherin, and gives them names appropriate to those tones. The characters have names like that, as well. "Draco Malfoy"? Draco comes from the Latin draconis, which means "dragon" (and the word draco still means "dragon" in Spanish), and "malfoy" has the root "mal-," which refers to anything that is evil or bad (malevolus, for example, means "ill-disposed, spiteful, malicious"; see also the Disney villain Malificent from Sleeping Beauty). The Headmaster at Hogwart's is named Dumbledore, and the word "dumb" is in there deliberately. Dumbledore isn't stupid, but like his archetype, he is at once powerful and wise, but also doddering and absent-minded (Disney comes back again; cf. Merlin from The Sword in the Stone, and for something different, cf. Buddhist sannyasi [pl. of sannyasin], old men who have acheived Nirvana but live as hermits and are kind of eccentric). Severus Snape? Again, Snape is clearly not to be trusted; his onamotapoetic name indicates that he is related somehow to a snake, which is true: he is the head of evil Slytherin house and a very nasty man in general.

Again, I say this may be a British thing because I've seen it out of Dahl and Rowling as well as Orwell, who worked physiognomy into Animal Farm and Nineteen Eighty-Four. How many American authors utilize this technique? It does in a few short words something that paragraphs of description couldn't do nearly as well. We're meant to like "Griffyndor" because of the heroic associations it conjures up (especially for the British, who would find a certain patriotic element in the image of the lion, one of the two animals on its seal), and we are meant to loathe "Slyetherin" because of its associations with snakes and serpents, animals which we perceive as ignoble, sneaky, treacherous, and possibly evil.