Laos was once described as less a nation state than a conglomeration of tribes and languages ... less a unified society than a multiplicity of feudal societies'. This is still borne out by the country's ethnic mix: Lao traditionally divide themselves into four categories - Lao Loum, Lao Thai, Lao Theung and Lao Sung - roughly classified according to the altitude at which they live, and, by implication (not always accurate), their cultural proclivities.
About half the population are ethnic Lao or Lao Loum. Of the rest, 10% to 20% are tribal Thai, 20% to 30% are Lao Theung (lower mountain dwellers, mostly of proto-Malay or Mon-Khmer descent) and 10% to 20% are Lao Sung (Hmong or Mien tribes who live higher up). The Lao government has an alternative three-way split, in which the Lao Thai are condensed into the Lao Loum group. Using that system, the majority are Lao Loum, about a third are Lao Theung and the rest are Lao Sung. This triumvirate is represented on the back of every 1000 kip bill, in national costume, from left to right: Lao Sung, Lao Loum and Lao Theung.
But which tribes belong to which category? There are officially 68 ethnic groups in Laos, classified according to many factors -language, history, religion, customs, dress etc. To divide these groups only by the altitude at which they live (especially since many tribes have been 'invited' down since 1975) is somewhat ludicrous. Recognising this complexity, ethnographer Laurent Chazee (see Books in the Facts for the Visitor chapter for details) has put forward a scheme of 119 ethnicities divided among Thal-Kadai, Austro-Asiatic (Mon-Khmer), Miao-Yao (Hmong-Mien), Sino-Tibetan and 'Others'. Several in the last category could go in one of the other four.