There remains a widely perceived notion that "Muslim" societies are especially resistant to embarking upon the path of demographic and familial change that has transformed population profiles in Europe, North America, and other "more developed" areas. In reality, however, fertility levels are falling dramatically for countries and sub - national populations throughout the Ummah — and traditional marriage patterns and living arrangements are undergoing tremendous change. This brief chapter will highlight some of these changes, examine some of their correlates and possible determinants, and speculate about some of their implications.