I liked the first 3 chapters of the book, which establish the basic building blocks of infant-parent communication, e.g. eye contact, smiles. As a new parent, it is helpful to know (beyond mere intuition) that these are the earliest forms of communication, and also when and how they are likely to appear (generally not until at least 6 weeks-3 months). I also found it interesting to explain my own innate behaviors/communication repertoire, eg exaggerated faces, baby voice. As the book proceeds, the author theorizes how these basic building blocks become dialogues and eventually relationships. This is the majority of the book and feels far more speculative/subjective/theoretical. I don't doubt (it is obvious) that relationships are built on repeated interactions, and that interactions in turn are built on more atomic forms of communication, but the author presents it in almost a mathematical way, kind of formulaic or like a recipe, which doesn't resonate with me. The book also becomes increasingly abstract and conceptual as it progresses into these theories.