This book is well written and well organized. Each chapter covers a specific area of Gender Differences (Sex Differences) as it relates to various cognitive abilities. The book begins with an introduction that presents a summary of the scientific method and explains some of the common falsies and social pressures that lead to incorrect conclusions. Each chapter then summaries some of the author's experiments as well as the work of other researchers. The end of each chapter then has a summary and end notes for the chapter. The book includes an appendix that reviews basic statistical math. And the book concludes with indexes.The book does not cover every observed difference between men and women. For example, it says nothing about the fact that there is a greater spread of IQ scores for men than for women. There are more male geniuses and more retarded males. Presumably because any features on the X chromosome are not dampened or enhanced by a second X chromosome. This incompleteness in no way takes away from the value of the book or it's quality.The subject, gender differences, is a very politically charged one and the author does an excellent job of avoiding the pressure to be politically correct and presents the findings as they are - except maybe in the differences in mathematical skills where she seems to work hard to find a way to explain away the differences between men and women ;)As much as I like the book, it does have a couple of weaknesses. Most notably the author tries, at times, to explain the finding with an evolutionary theory. The problems with this are: the facts do not need to have an evolutionary reason, the facts are sufficient in themselves. Second, evolutionary theories cannot be verified. They are not scientific, they fall more in the realm of religion.Another, minor, annoyance is that figures and tables are often several pages away from where they are referenced.I began reading the book skeptically, expecting political correctness, I was pleasantly surprised. I was originally going to give it four stars because of the evolutionary theories given, but the more I read, the more I think it deserves five.I would recommend this book as a place to start study of differences between men and women. I also believe it would make a good text book in a gender studies course. I like it so much that I have already purchased several copies to give away. There can be no higher recommendation than that.