The separation of men and women in prayer is not universal among Muslims. In the mosque built around the Ka’bah, men and women are not separated, but pray together in circular formation around the shrine. In Turkish mosques women pray in balconies above the prayer hall for men, and in some American mosques women pray parallel to men while in others they pray behind the men.
The reason usually adduced for this practice involves notions of modesty. The Muslim ritual prayer is very physical in nature, involving standing, bowing, and prostrating oneself. While in congregational prayers, Muslims are supposed to stand side by side and shoulder to shoulder with those next to them. Many Muslim cultures have considered it distracting or immodest to have men and women praying side by side or to have women prostrate themselves in front of men.