Social scientists everywhere have an interest in understanding and explaining what happens in the world. In this anthology, Vayda and Walters aid social scientists with strategy and methods to answer their causal questions. The selected readings are not only by anthropologists, sociologists, economists, and human ecologists, but also by philosophers, biologists, historians, and specialists in various other fields. It will appeal to those doing applied research on practical problems, as well as to those seeking to satisfy their intellectual curiosity about why things happen.