This is a great book. I attended the LPMA training from Spencer, Shenk and Capers last year and the course was based partially on this book. It is a good book to read to gain an understanding of core motivational factors of behaviors. I thought it was a great read but most will find it full of useless stats.
I only heard of this book through one of my close friends, but I decided to read it because of her glowing recommendation.
This book, beyond any doubt, is good. My only problem with this book is that it's so intensely academic, I had a hard time following it through its entirety. McClelland capably studies different cultures throughout time and assesses what made a few of them progressive and achieving. Important in these cultures is other-directedness and a high need for achievement. This was shown in Protestant countries, in Japan (in spite of their traditional ways), and in other societies as well.
It is copiously researched and intensively prepared by McClelland. Is it an easy read? Definitely not.
I totally recommend this book. I enjoyed reading it and also learning about facts that make people and societies to be successful o unsuccessful. Not only facts but characteristics.