This is a "socal" guide book, not a "tour" guide book. It aims at making sure you are a conscientious traveler who can visit and mingle in a new place well - and for that I am very grateful. I just spent three weeks in India and found that basically everything I read in the book about their social behaviors and norms was true - and it is helpful for understanding how things work in India.
This book is particularly useful when you want to spend time around people in the host country you visit. The people of India are very helpful (sometimes too helpful), and they like to foster relationships, but they don't do things the same way that we do in the USA. This book will help you to understand the 'why' of their behavior so that you can temper your expectations correctly and have a pleasant stay.
I LOVED this book, and found it to be a true insight into the social norms in India and the social motivators: Family is king, language is a source of pride, collaboration is more important than results, saying 'no' is rude - so you will get an answer even if the person does not know. These are just some of the helpful insights of the book. Heck, even some of the Indians I was travelling with were surprised by the wealth of knowledge it provided me.