Justin Bieber was named Artist of the Year at the 38th annual American Music Awards this evening, beating out formidable contenders Eminem, Ke$ha, Lady Gaga, and Katy Perry, at the wee age of 16. Biebs took home a trophy for every category in which he was nominated, the others being Favorite Pop-Rock Album, Breakthrough Artist, and Favorite Male Pop Artist. Meanwhile, his mentor Usher won the R&B/Soul award for Raymond v. Raymond, Carrie Underwood nabbed the Top Country Music Album award for Play On, the Black Eyed Peas won Best Pop/Rock Band, and Taylor Swift won for Favorite Female Country Artist. The AMA winners were determined by real-life American voters. [HR, People]