When we talk about American ethnic groups, what do we mean?.

Abstract
American ethnic groups are often thought of as discrete categories to which people belong and that explain some aspects of psychological functioning. However, ethnicity is a complex multidimensional construct that, by itself, explains little. To understand its psychological implications, it is necessary to identify and assess those aspects of ethnicity that may have an impact on outcomes of interest. In this article, the author examines 3 key aspects of ethnicity: cultural norms and values; the strength, salience, and meaning of ethnic identity; and the experiences and attitudes associated with minority status. These aspects are best understood in terms of dimensions along which individuals and samples vary, rather than as categories into which individuals can be classified. (PsycINFO Database Record (c) 2007 APA, all rights reserved) (journal abstract)