Mahler proposed five overall phases of separation-individuation. The first two stages, which extend from birth to four to five months, are considered forerunners of the actual process of separation-individuation. The next three stages are termed sub-phases of the separation-individuation phase proper. Differentiation starts at four to five months and continues until about ten months. Practicing ranges from about ten months until sixteen to eighteen months. Rapprochement ranges from about eighteen months to about two years. After the child comes out of rapprochement, the child is in the beginnings of emotional object constancy, the final subphase of the separation-individuation phase, which extends from two years to about three years.