Abstract
This chapter is concerned with the emergence of emotional communication—transactional emotions—early in life. The authors review methodological and conceptual issues in research on early interaction, and then present two studies of emotional communication. The first study uses computer vision to describe infant-mother interaction from a micro-analytic perspective. It reveals evidence of changing infant-mother emotional dynamics during the course of interaction. The second study formally models these changing dynamics utilizing continuous ratings of affective valence. Each study utilizes a different approach for continuously measuring emotion during interaction that may resolve methodological impasses and shed new light on emotional transactions.