Modern American infant research attempts, above all, to refrain from using psychoanalytic developmental theories to establish hypotheses about the infant’s earliest experiences. Rather, it is based instead upon the most precise, often experimentally supported observations, with the least possible amount of presuppositions. In contrast, analysts have concentrated on developing their hypotheses in the context of the emerging clinical picture. Their early childhood theories are thus influenced by this point of departure. This is the case, for example, with S.Freud, M.Klein, R.Spitz, and also M.Mahler.