Corporal punishment--the intentional infliction of pain with the intent of changing unacceptable behavior--is allowed in schools in 22 States. Two to three million incidents of corporal punishment are estimated to occur each year. Methods of corporal punishment include hitting, slapping, spanking, shaking, punching, kicking, choking, electric shock, confinement in small spaces, excessive exercise, and fixed postures for long periods. Instruments used in corporal punishment include leather straps, switches, baseball bats, and fists. As a result of corporal punishment, 10,000 to 20,000 students request/need medical treatment each year. Serious injuries and long-term damage have been documented as a result of hitting or spanking. Opponents of corporal punishment argue that it promotes acceptance of physical violence and force by persons in authority. Some researchers claim that using violence to discipline children encourages them to use violence in efforts to control peers. Opponents also argue that there is no evidence that corporal punishment produces positive behaviors. Supporters of corporal punishment, on the other hand, claim that it produces immediate decreases in negative behavior; some research supports this claim. Advocates of corporal punishment believe it produces respect for authority, obedience, and self-discipline. Legal action by students subjected to corporal punishment requires that they prove the punishment was excessive. Behavioral scientists generally advocate changing behaviors through a combination of reward, positive motivational techniques, and nonphysical punishment tailored to the misconduct.