Van den Berghe contends that intergroup relations are reducible to individuals competing for scarce resources. While social classes are grouped according to common material interests, ethnic groups are organized by real or punitive common descent—ultimately on the basis of common interests. The author argues that ethnic nepotism is, at its very foundation, biological. This new approach is expanded further, taking into account how ethnicity is responsive to a wide spectrum of environmental factors. He analytically relates his own ideological biases to the substance of his work. What results is an intensely personal book of monumental scope and admirable intellectual honesty.