Tribes may embody diverse kinship rules, structures, types of political authority, and lifestyles (sedentary, semi-nomadic, nomadic),5 which may be influenced by security and economic conditions and government policies.6 Thus, for instance, the Arab tribes of the Arabian Peninsula, Levant, and North Africa tended, at least traditionally, to be relatively egalitarian and non-hierarchical organizations lacking a well-developed leadership structure, while the Turkic tribes of the Central Asian steppes tended to be hierarchical, highly centralized organizations ruled by powerful chieftains.7 Although Arab tribal ideology is relatively egalitarian, in reality, major disparities in status, power, and wealth exist within and between tribes.8 Among settled tribes, sheikhly families and clans te...