"In this overview of the evolution of human society, Carl Coon argues that the twenty-first century will witness a crucially important and difficult transition for the human race. Blending the disciplines of anthropology and evolutionary psychology with over thirty years of experience in the diplomatic corps, Coon traces the evolution of the human tendency to divide others into two groups, "us versus them." People tend instinctively to behave altruistically toward members of their own in-group and to react with suspicion, or even hostility, toward outsiders. He points out that complex human societies became possible only when cultural attitudes encouraged individuals to define their in-groups in more expansive ways. Thus, small, kin-based bands grew into villages, kingdoms, and eventually, the modern nation-state, Today, he argues, we have reached a stage where the whole world must be viewed as "us," for only a united world community can cope with current global challenges."--Jacket.