Introduction -- pt. 1. Theoretical perspectives: Attachment and reflective function : their role in self-organization ; Historical and interdisciplinary perspectives on affects and affect regulation ; The behavior geneticist's challenge to a psychosocial model of the development of mentalization -- pt. 2. Developmental perspectives: The social biofeedback theory of affect-mirroring : the development of emotional self-awareness and self-control in infancy ; The development of an understanding of self and agency ; "Playing with feality" : developmental research and a psychoanalytic model for the development of subjectivity ; Marked affect-mirroring and the development of affect-regulative use of pretend play ; Developmental issues in normal adolescence and adolescent breakdown -- pt. 3.Clinical perspectives: The roots of borderline personality disorder in disorganized attachment ; Psychic reality in borderline states ; Mentalized affectivity in the clinical setting -- Epilogue.