To varying degrees, these scales have been conceptually rooted in Mahler ' s (Mahler et a l . , 1975) theory of separation-individuation. Mahler observed and described the steps in the separation-individuat ion process, which begins w i t h the earliest signs of the infant's differentiation or hatching f rom a symbiotic fusion w i t h the mother; proceeds through the period of the infant's absorption i n its o w n autonomous functioning, to the near exclusion of the mother; continues through the all-important period of rapprochement, in which the chi ld, precisely because of a more clearly perceived state of separateness f rom mother, is prompted to redirect attention back to mother;

and finally culminates in a feeling of an early sense of self, of individual identity, and of constancy of the object.