In this study, attention is drawn first to the fact that, in the complex fabric of development woven by the mutual interactions of ego, id, evolving self, object relations, and life experiences, this study looks only at the interactions of instinctual drives and symbiosis/separation-individuation. The instinctual drives are powerful psychobiological motivating forces, whereas symbiosis/separation-individuation is a developmental process that unfolds during the first three years of life.

I have suggested that an upsurge in aggression thrusts the symbiotic-phase child into the separation-individuation phase and process. Material from longitudinal direct observations of two of our project children is presented to document this hypothesis. I have further proposed that, given normal enough developmental conditions, biologically predetermined differentiations in the instinctual drives trigger the various phases and subphases of symbiosis and separation-individuation during the first three years of life.