When I first saw the title of the book I thought at the series "Lie to Me". Unfortunately, the book was far from what I expected. And this not because it uses advanced and specialized terms in psychology, but because it treats the subject from a sort of psychological-mystical point of view.
The book is hard to read because it is structured like a dictionary. Gestures and physical aspects of the human being together with their corresponding symbolism are put into categories, enumerated and explained one after the other. I think this book is more useful if someone read only the gesture or physical feature he is interested in at a certain time rather than reading the entire book at once. Often there were moments when I had difficulties focusing and my mind was flying in other places while reading. In addition to this, and probably the most important thing, there were times when I had the feeling I'm reading astrology or something like that from the area of mysticism. Or that I'm re-reading the expired theories of the 19th century regarding the identification of criminals based on their physical features.
I cannot deny the expertise of the authors - who, according to them, have more than 20 years of experience in this field - but I can tell for sure that people can scratch their back with the left hand or the right hand for many reasons, not only because they are bothered by the person speaking in front of them (this is just a silly example made by me to emphasize things). People act or look in one way or another also because they might be forced to the limitations of their body, not because they feel or think something. Moreover, I noticed that most of the explanations given were negative, in the sense that people are prone to act or look in a certain way when they are driven by bad stimulus.
Bottom line, many of the things explained in the book did not make sense to me.