"Negative ethnicity" is Koigi wa Wamwere's name for the deep-seated tensions in Africa that the world has seen flare so terrifyingly. The genocide in Rwanda and "ethnic" killing in the Democratic Republic of Congo, Nigeria, and elsewhere stand out as examples. Wa Wamwere argues that these clashes cannot properly be described as ethnically motivated; ethnicity, a positive distinction, has nothing of the hatred here at work. Negative Ethnicity gives...