Divergent: Divergent Series, Book 1 (paperback) Veronica Roth
One choice can transform you. Beatrice Prior's society is divided into five factions—Candor (the honest), Abnegation (the selfless), Dauntless (the brave), Amity (the peaceful), and Erudite (the intelligent). Beatrice must choose between staying with her Abnegation family and transferring factions.
Her choice will shock her community and herself. But the newly christened Tris also has a secret, one she's determined to keep hidden, because in this world, what makes you different makes you dangerous.