In Angelina Jolie's new movie, Changeling, she doesn't actually play the changeling -- that's her son. Over the last decade, however, has there been any star more mercurial than Jolie, whose image has gone from blood-drinking wild child to globe-trotting humanitarian to the world's most glamorous mom of six? Well, maybe one, at least on a follicular level. That, of course, would be her partner Brad Pitt. Which one possesses the most expressive, most eclectic, most astoundingly mutable hair? Below, we provide the scientific evidence that definitively answers this much-speculated-upon question.

1. Is the subject's hair capable of turning multiple different colors, like a chameleon?

2. Does the subject's hair possess the power to radically alter wind patterns?

3. Is the subject's hair as soft and glossy as a unicorn's mane?

4. Can the subject's hair do a passable impression of Little Richard's early career pompadour?

5. Does the subject's hair look good even when the subject is wearing a really hideous dress?

6. Can the subject's hair enlarge itself to several times its normal volume when frightened or attempting to mate?

7. Does the subject's hair sometimes look as if it were gently tussled by angels with Parkinson's disease?

8. Can the subject grow copious amounts of golden blond hair on its face, until it resembles a homeless golden retriever?

WINNER: BRAD PITT!