From what I know.
-It seems that the Yi are very diverse. Some seem to be more related to the Qiang, while others more related to Miao.
-most, if not all, speak a language in the Tibeto-Burman family. Some dialects appear to be unintelligible to other Yi groups.
-Chinese records state that they descendent from the ancient Qiang. Perhaps there is some linkage between these peoples and groups such as the Nanman, etc.
-They had a complicated system of slaves, in which you had your elites, and varying levels of slaves. Some of which also owned their own slaves. Naturally this all came to an end when the PRC was established.
anyone with more info?
pics from the net:
Yi clothing (male and female)

some of the varying Yi headdresses for females



Yi writing
http://www.omniglot.com/writing/yi.htm
