 A number of medical, pediatric or psychological societies have issued statements opposing all forms of corporal punishment in schools, citing such outcomes as poorer academic achievements, increases in antisocial behaviors, injuries to students, and an unwelcoming learning environment.They include the American Medical Association, the American Academy of Child and Adolescent Psychiatry, the American Psychoanalytic Association, the American Academy of Pediatrics (AAP), the Society for Adolescent Medicine, the American Psychological Association, the Royal College of Paediatrics and Child Health, the Royal College of Psychiatrists, the Canadian Paediatric Society and the Australian Psychological Society, as well as the United States' National Association of School Psychologists and National Association of Secondary School Principals.Men spanking their wives and girlfriends was often seen as an acceptable form of domestic discipline in the early 20th century as a way to correct behavior, maintain male dominance, and enforce gender norms.