Despite its small population, Laos has no less than 68 tribal groups. About half of the population are Lao Loum, "lowland Lao" who live in the river plains. Officially, this group includes the Lao Tai, who are subdivided into numerous subgroups. The Lao Theung (20-30%), or "upland Lao", live on mid-altitude slopes (officially defined as 300-900m), and are by far the poorest group, formerly used as slave labor by the Lao Loum. The label Lao Sung (10-20%) covers mostly H'mong and Mien tribes who live higher up. There are also an estimated 2-5% Chinese and Vietnamese, concentrated in the cities.
Laos is officially Buddhist, and the national symbol, the gilded stupa of Pha That Luang, has replaced the hammer and sickle even on the state seal. Still, there is a good deal of animism mixed in, particularly in the baci (also baasi) ceremony conducted to bind the 32 guardian spirits to the participant's body before a long journey, after serious illness, the birth of a baby or other significant events.
Lao custom dictates that women must wear the distinctive phaa sin, a long, patterned skirt, although tribal groups often have their own clothing. The conical Vietnamese-style hat is also a common sight. These days men dress Western style and only don the phaa biang sash on ceremonial occasions. Nowadays women often wear western-style clothing, though the "phaa sin" is still the mandatory attire in government offices (not only for those who work there, but also for Lao women just visiting).
