Thailand is a country with many distinct ethnic groups, like other countries, including the majority Thai and numerous groups referred to as hill tribes living primarily in the mountains of the north. The Thai (or ethnic Tai/Dai) and Thai Chinese make up approximately 90% of the nation's population of approximately 67.5 million.
Khmer and Mon-Khmer make up approximately 6%, the Malays of Southern Thailand make up around 3%. Among the groups categorized as hill tribes, Hmong (Mien), Karen and other small hill tribes make up around 1%. There are 70 ethnic groups in Thailand, including 24 groups of Tai peoples.
In the Thai official documents the term "hill tribe" (Chao Khao) began to appear in the 1960s. This term highlights a "hill and valley" dichotomy that is based on an ancient social relationship existing in most of Northern and Western Thailand, as well as in Sipsongpanna and Northern Vietnam. For the most part the Dai/Tai/Thai coccupied the more fertile intermontane basins and the valleys, while the less powerful groups lived in the less rich higher altitudes. This dichotomy was often also characterized by a master/serf relationship