Yang's illustration of the various "schools of thought" used by social scientists over time help you better understand ethnicity?

explain how or whether Yang's illustration of the various "schools of thought" used by social scientists over time help you better understand ethnicity? Read Ethnic Studies: Issues and Approaches, by Philip Q. Yang - Chapter 1, 2 and 3 Required Text: Yang, Philip Q. Ethnic Studies: Issues and Approaches. New York: State University of New York Press, 2000. – ISBN # 0-7914-4491-1