Instruct: Classify Amazon reviews into positive or negative sentiment
Query: A Seminal Book, A Theory that Explains A Lot

This book belongs on the shelf along with "The Origins of Consciousness in the Breakdown of the Bicameral Mind", "The Moral Animal", "Non Zero", "The Third Chimpanzee" and "Darwin's Dangerous Idea". It is a brilliant theory of the origins of language, supported by statistical analysis of physiological data (relative cortex size of primates, including humans), sociological data (the size of human groups across societies ranging from hunter gatherers to modern armies) and current social psychology experiments by his grad students (spot checks of random conversations in malls and pubs). Well supported, and startling, you will look at your society and your use of language differently.