Opinião de um leitor q. Gostei muito.  fonte: Amazon Do You Want to Know Why Hierarchies Exist in Human Society? By Jeff on July 4, 2014 I bought this book about 5 years ago, read it then and just re-read it. For those who aren't sure if they want to buy the book, I'd recommend searching for a PowerPoint presentation on the book created by Dr. Brian Paciotti - do a search on that name to find his website. Then, click on "Teaching" and "Interethnic Contacts" - the PowerPoint presentation is Lectures 9 & 10. Dr. Paciotti has admirably summed up the arguments in the book and reading through his presentation will give you an idea of whether or not you want to buy the book. I found the book's thesis to be sound because the core of the argument is that in all human societies which generate an economic surplus (this leaves out hunter-gatherer societies), there are three characteristics: discrimination based on age, gender and what Sidanius and Pr