Sex segregation is the physical, legal, and cultural separation of people according to their biological sex. It is practiced in many societies, especially starting when children attain puberty. In certain circumstances, sex segregation is controversial.[57] Some critics contend that it is a violation of capabilities and human rights and can create economic inefficiencies and discrimination, while some supporters argue that it is central to certain religious laws and social and cultural histories and traditions.[58][59] Purdah is a religious and social practice of female seclusion prevalent among some Muslim and Hindu communities in South Asia.[60] It takes two forms: physical segregation of the sexes and the requirement that women cover almost entirely their bodies.