The Sotho-Tswana people would have diversified into their current arrangement during the course of the 2nd millennium, but they retain a number of linguistic and cultural characteristics that distinguish them from other Bantu-speakers of southern Africa. These are features such as totemism, a pre-emptive right of men to marry their maternal cousins, and an architectural style characterized by a round hut with a conical thatch roof supported by wooden pillars on the outside. Other major distinguishing features included their dress of skin cloaks and a preference for dense and close settlements, as well as a tradition of large-scale building in stone.