This is obviously a topic too deep and voluminous to fit into a single book but it's my opinion the author does a reasonably good job of it. I felt, however, that the author submitted too many sweeping conclusions, by drawing causal links between observations of behavior and their underlying psychological motivation. This was also true of the author's claims as to the cause of extinction of megafauna during the Stone Age. These sorts of firm declarations were unnecessary in most cases, and in others were simply wrong, despite being the conventionally accepted wisdom on the subject matter. A more speculative tone and approach on the author's part might have been more engaging to the reader, and honestly a more accurate assessment of our true understanding of things. Despite that, the work was a worthwhile read that did and excellent job of encapsulating one of the broadest topics imaginable. Readers will walk away with at least a general concept of our origins, with details on the ingredients that made up the eventual survival success story of humans.