All groups in the Lao-Tai family cultivate wet-field rice, most commonly glu- tinous varieties. They live in sedentary villages, often quite large, of houses built off the ground on stilts or poles. Social distinctions persist, separating aristocrats from commoners. Most are Buddhists, and all propitiate local spirits (phi). The Lao-Tai family forms the general category of Lao Loum, or lowland Lao (UNDP 2002). The 30 officially recognized ethno-linguistic groups of the Austroasiatic family can be divided into five subcategories, of which two—Palaungic and Khmuic—are located only in northern Laos, one (Vietic) is confined to a strip along the Lao-Viet- namese frontier, and the remaining two—Katuic and Bahnaric—are found only in the plateaus and mountains of southern Laos. Chazée (1999, p 51) reports having identified 59 distinct ethnic and “subethnic” minorities in this family. Many of the largest group are the Khamu, accounting for 11% of the Lao population. The two largest groups in the south are the Katang (2.1%) and the Makong (2%). No other group numbers more than 1%. The minorities composing the Austroasiatic family all live at higher altitudes than the Lao, in smaller villages containing houses on shorter stilts or poles. Some produce rice in rainfed paddies; others grow dry-field rice using slash-and-burn meth-ods. Communities are not hierarchically stratified, but kin groups may be identified with totemic animals. Most are animist, worshipping a variety of spirits identified with the locality, house, or family. Some have converted to Buddhism or Christianity through contact with Lao neighbors or foreign missionaries. Together these minorities in the Austroasiatic family constitute the general category of Lao Theung, Lao of the (mid-altitude) slopes. The Hmong-Yao group contains the Hmong (6.9%) (divided by Chazée into two subgroups) and two smaller Yao minorities together amounting to 0.5%. Eight Tibeto-Burman minorities are officially recognized, of which only the Akha (1.9%) account for more than 1% of the total population. In contrast, Chazée recognizes 33 ethnic and subethnic groups. Both Hmong and Yao are further divided into exogamous patrilineal clans, 15 for the Hmong and 12 for the Yao, who are further divided into subclans. Most reside at higher altitudes than the Austroasiatic minorities, and differ from them by building their houses on the ground. They grow nonglutinous rice using slash-and-burn methods. Both have been influenced by centuries of contact with the Chinese before migrating to Laos, the Yao more than the Hmong. For example, the Yao use Chinese characters to write their religious and customary texts, and for both the worship of ancestral spirits is important. The Tibeto-Burman minorities are mostly confined to the far north of Laos in the province of Phongsaly. They generally live at slightly lower altitudes than the Hmong and Yao, but like them build their houses on the ground. They are also swidden farmers who prefer nonglutinous rice to the glutinous varieties. Each group worships its own pantheon of animist spirits, except the Phounoi, who have converted to Buddhism. Minorities of the Hmong-Yao and Tibeto-Burman families are together referred to as Lao Soung, Lao of the mountain tops. The persistence of the extraordinary ethno-linguistic diversity in Laos reflects, in part, past difficulties in communication throughout the country. The diversity and his- tory of the individual ethnic groups are also reflected in the diversity of, and within, the rice-growing environments within the country that have also persisted until relatively recently, and which are reported elsewhere in this book. Changes, both government- initiated and as a direct result of improvements in communication, are resulting in increased interaction among the ethnic groups, with minority groups having increased contact with the ethnic Lao majority, particularly as a result of education initiatives and increased commercialization of agriculture. Traditional upland cultivation prac- tices based on slash-and-burn systems will be replaced by more sustainable forms of agriculture. In the lowland environment, modern improved rice varieties have already largely replaced traditional varieties. Fortunately, extensive germplasm collections undertaken during 1995 to 2000 will enable the conservation and preservation of much of the traditional rice germplasm of Laos (see Chapter 9). However, much of the indigenous knowledge associated with past traditional agricultural practices has a high probability of being lost. Government policies are not the only basis of the changes that are taking place in Laos. As in other parts of Southeast Asia, people of Laos are moving from villages into towns to seek employment and a better life. Although this is a movement that is now primarily affecting ethnic Lao, it is also likely to affect ethnic minority families in the future as differences in standards of living increase between the provincial cities along the Mekong and rural areas. Considerable internal migration is already taking place within provinces as families move to district and provincial capitals (Bounthavy and Taillard 2000, p 50-57).