If you're envious of Sarah Jessica Parker and Taylor Swift's signature curls but have stick straight hair, read on! You're that much closer to wavier locks thanks to the discovery of the "curly hair gene." Scientific treatments are now being developed to make hair curlier—or straighter like Tyra's and Gwyneth's—without the use of heating tools! Not sure whether to go curly or straight? Try on these star looks with our Hollywood Makeover tool.