Book 4 introduces interactive regulation: How we regulate each other. Terminology for thinking about self regulation in a one person system and self regulation in a two person system help clarify our cultural confusion about relying on other people for our emotional balance.
The Graphics and language are based on news form the field of Interpersonal neurobiology. Interactive regulation skills are a form of cultural capital that allow us to take on big challenges without getting combative, avoidant or overwhelmed.