Other forms: recusants
Someone who refuses to participate in a socially expected activity (especially when they decline to go to church) is a recusant.
Between the 16th and 18th centuries, anyone who broke church rules by refusing to attend services would be labeled a recusant by the Church of England. Today, a recusant might defy authority in other ways: "Once again, the recusants ignored my instructions to get in line after recess." Or use the word as an adjective, like when your recusant brother refuses to stand for the Pledge of Allegiance. The Latin root is recusare, "decline, refuse, or reject."