Siouan languages
Authors who call the entire family "Siouan" distinguish the two branches as "Western Siouan" and "Eastern Siouan" or as "Siouan-proper" and "Catawban". Others restrict the name "Siouan" to the western branch and use the name "Siouan–Catawban" for the entire family. Generally, however, the name "Siouan" is used without distinction.
Simeulue
From the ethnic point of view the inhabitants of Simeulue are similar to the people of neighboring Nias Island. Two languages and a number of dialects are spoken on the island: Devayan and Sigulai, which are different from the languages spoken in the north of Sumatra. The majority of the island's population is Muslim.