Don't judge a girl by her hair color.

We're all familiar with the stock descriptions cool blonde, sassy brunette, and fiery redhead – as if a person's hair color were a significant clue to their personality. We naturally make assumptions about people’s personalities according to their looks (or physiognomy, if you want to be fancy and technical) – sensual lips, soulful eyes, etc. – but nothing provides a result as effortlessly as hair color. Red hair, for instance, even if it’s not accompanied by an adjective such as “fiery,” projects a vibrant, independent personality. It's almost counter-intuitive to think of a redhead as icy, weak, or boring.

King David was supposedly a redhead, and though it doesn't say anywhere in the Bible that she was, Mary Magdalene frequently turns up in art with rosy tresses. Brigid O'Shaughnessy, The Maltese Falcon's delicious femme fatale, is another notable redhead. On the opposite end of the innocence spectrum, there's Anne (of Green Gables) Shirley with her carrot-colored curls. In the black and white film version of The Maltese Falcon, Miss O'Shaughnessy's hair color couldn't register, and neither could the locks of spoiled socialite, Tracy "Red" Lord, in The Philadelphia Story.

You need Technicolor for that kind of thing: Vicky Page, the doomed ballerina in The Red Shoes; Mary Kate Danaher, the tempestuous spinster (and then wife) in The Quiet Man; and Glinda, the Good Witch of the North in The Wizard of Oz. Speaking of redheaded witches, Buffy has Willow Rosenberg (though she and Glinda don't hail from the same coven). Bree van de Camp is the special red brand of soapy goodness on Desperate Housewives. And while we're on the subject of television, someone on the Mad Men crew simply adores redheads: Joan, Peggy, Helen Bishop, and Bobbie Barrett. Cartoon-wise, Ariel the Little Mermaid and Jessica Rabbit immediately come to mind.

Aside from the fact that all of these (with the exception of King David) are females, they also have an unconventional, feisty nature in common – whether they're witches, housewives, socialites, secretaries, or femme fatales. There is also the time-honored tradition of casting redheads as prostitutes with hearts of gold – Mary Magdalene, Belle Watling (Gone with the Wind), Vivian (Pretty Woman), and Satine (Moulin Rouge). You can do this sort of character-analysis-by-hair-color for blondes and brunettes and come up with some common denominator – which may seem either less or more arbitrary. Yes, blondes are sophisticated or dumb, and brunettes are adorable or bitchy, but if she has red hair, whether she's good or bad, nice or nasty, she will be extraordinary, rebellious.

On a somewhat off-topic note, I'm curious where "dumb blonde" comes from. I suspect it didn't originally imply "stupid", but silent – as the ideal (for women) was to be fair and quiet. Thus Brunettes, by default, wound up being known as smart, since "dark" is the opposite of fair. Red, though it can vary in shade, doesn't quite fall into either category. Hence, apart from the natural association of red with fire and all its connotations, the additional rebellious quality attributed to redheads. After all, you can have a rotten temper and still be a conformist. But I'm simplifying – hugely.

Any character functions on the basis of more than something as superficial as hair color. There are surely fictional redheads that don’t fit the rebellious model (though I can’t come up with any specific examples at the moment), just like there are hot-blooded blondes and dumb brunettes – and any character can be a misfit regardless of hair color. The crucial point, I think, is that when we pick a character’s hair color, we sometimes let it shape the character more than we realize. Or vice versa – we’ll pick the color according to the personality type.

So here’s to breaking the old molds and making new ones.