Certain topics of human experience are repeatedly explored, consistently receiving ineluctably partial answers. Developmental psychology has a rich history of research on such topics. It studies how the first interpersonal encounters emerge, how intimacy and intersubjectivity between adult and baby develop; it explores the development of perceptual abilities that allow babies to become involved in the interpersonal world; it deals with the unfolding of gestural and verbal communication skills, and it elucidates the complexity of play in infancy. Academic knowledge on these topics increased in the last decades and new questions and research strategies emerged. Our Research Group on Socio-Cognitive Processes in Infancy and Early Childhood, at the Psychology of Knowledge and Learning Department in FLACSO (Facultad Latinoamericana de Ciencias Sociales/ Latin American Faculty of Social Sciences) in Argentina, focuses on these topics. They are all addressed in one or more chapters of this book. Our approach to them is a product of interdisciplinary cooperation. This book was shaped through the meetings of our research group in developmental psychology, including what we consider the extended team ?which includes members of SACCOM (Sociedad Argentina para las Ciencias Cognitivas de la Música/ Argentine Society for the Cognitive Sciences of Music) and SADAF (Sociedad Argentina de Análisis Filosófico/ Argentine Society of Philosophical Analysis). Based on these encounters, we generated a conception of developmental psychology in permanent dialogue with the psychology of music, the philosophy of mind and human movement studies.