Status Updates From Reflective Parenting

So far I've only read the introduction but it looks like this could be the book I'm looking for. The theories that lay at the base of the book are all about understanding what is going on in a child's brain, how he sees & understands the world and how adults can read into the child's reactions on the outside to understand what is going on inside. Curious to see if they refer to really young children - esp toddlers.