The anal and later stages of development have been somewhat neglected in the last two decades due to interest in the oral and prenatal stages. The anal stage not only receives contributions from the oral stage but makes its own unique contributions. The oral experience reinstates the original oneness of mother and infant, whereas the anal experience denotes withdrawal from the mother and autonomy. In this later stage of ambivalence, narcissism is expressed by aggression, self-assertion, contrariness, and sadism, and the sense of identity depends largely on the opposition: 'I against you.'