Sibling terms in Asia and Africa: A geolinguistic approach to linguistic patterns

Sibling terms in Asia and Africa are examined by making new maps, each of which shows detailed distributions of each type of sibling term system. The interpretation of the maps strongly supports a previous interpretation, as follows: (1) Change from Type A to Type B and from Type B to Type C can be inferred from the distributions, (2) Type D and Type E expanded relatively recently, and (3) Type F shows the relic, peripheral distributions.