Unit houses are occasionally referred to as _clan houses_, for some archaeologists believe that they may have been occupied by single family groups. Present day social organization in the western pueblos is based on clans, and it is believed that this is of long standing and probably extends far back into prehistoric times. Descent is traced in these pueblos in the maternal line. In such villages a clan is a group made up of individuals descended from the same female ancestor. Houses belong to the women, and a family group which lives together usually consists of a woman and her daughters and their families. The husbands belong to other clans. They live with their wives’ groups, but their religious affiliations are with their own clans. The kivas, or ceremonial chambers, belong to the men of the clan and serve as club rooms as well as providing a place where secret religious rites may be performed. In Developmental-Pueblo times, kivas were very similar in form to those used at the present time in the eastern pueblos. They were circular, subterranean structures which lay to the south or southeast of houses. Walls were of masonry, and there were encircling benches in which pilasters were often incorporated. Roofs were normally cribbed, and entrance was usually through the smoke-hole in the center; although, in some unit-type sites in southwestern Colorado, stone towers are found containing manholes which led into tunnels connecting with kivas.[83] It is interesting to note the apparent derivation of kivas from the old domiciliary pit houses which had, at least in a rudimentary form, all of the features of the later religious structures and which also lay in the same position in relation to the surface masonry structures. It is believed that originally each house had its own shrine. When special structures came to be built exclusively for the performance of religious rites, the people clung to the old form of building, although their dwellings were developing in a different direction. There is an innate conservatism and traditionalism in religion which is well represented in architecture. In our own cities, where we erect medieval cathedrals and sky scrapers, we can see a lag of from four to seven centuries between religious and secular architecture. In some parts of the Southwest, kivas were not the only places available for the performance of religious rites. At Allantown[112] was found a great circular area, paved with adobe and enclosed on three sides by upright stone slabs, which is believed to have been a dance court. On the north side is a platform or dais. Probably in that long ago time there were many days and nights when moving feet beat out the intricate rhythms of the dance against the hard packed adobe, as the gods were importuned to bring life-giving rain for the crops.