The book is interesting, well written, and covers much of the recent research on collective or group decision making, but it has glaring oversights. The author is most at home in economics where the book does the best at reporting research findings, but his references to social conformity are very limited despite that being at the core of the book. He completely overlooks research on the nonconscious dimension of decision making and implicit or automatic learning (at the basis of stereotypes and racial prejudice), and he neglects negative findings that groups may not outperform the best individuals in problem solving. From a reading of the book alone, one would never expect to see something like racial discrimination, the Holocaust, or the Taliban emerge in a society. Although the title refers to "societies and nations", the book only concerns the United States. Toward the end of the book, his accounts of the academic review process, the progress of science, and voting theories are naive at best. The book has no index.