I'd give it 4 stars--On the Piper Patter rating scale, it's a Borrow It. Glad it came from the library, but then I don't buy many nonfiction books anyway.
This book is a great explanation for why sometimes people just "click". Many reasons, from being a part of something, to similarities, to basic proximity. Probably the most interesting part of the book for me was the discussion about "high self-monitors"--people who are skilled at regulating their moods, actions, voice levels according to differing social situations. They seem to go really far in life--and knowing the difference between them and "low self-monitors" can be very helpful when writing different character types.