Thoughts on the Latency Period

One of the principles of development is to produce the product of past development and for further development, with as perfect an Anlage as possible; in other words, to postpone the end of intrauterine development as much as possible, to go through a maximum of phylogenetic developmental phases, physical and mental, before birth. As the ontogenesis repeats the phylogenesis, the early stages serve as raw material, provide mere intensity for later stages, and, the earlier they take place, are the more completely repressed in their phenomenological detail. On the other hand, those functions that naturally or necessarily have remained unchanged through a long period of phylogenesis still have contact with archaic mental or emotional correlates, in spite of intervening latency periods, as proven, e.g., by unconscious behavior and the language of the dream.

We are no longer plagued with the problems of fishhood. The occasional atavism or developmental arrest like a persistent thyroglossal duct is just a reminder of a bygone day. We can say that we are biologically born with everything present that developed through the ages as reaction to reality, everything that is basic and everything that we shall use in the life before us, as soon as it develops sufficiently to be usable. But the psychological development is lagging. It has an additional potentiality: it can develop basic trends after birth. Moreover, if the human body stays at its present developmental stage, the mind can apparently continue to develop for a very long time, changing, as it does, its environment and responding to the changes which it creates.

Psychologically the intrauterine life has to be prolonged extrauterinally to catch up with the physiological development. The actual interplay with the outer world is necessary for this purpose. Light, noise, change of temperature, the pleasures and displeasures of social life with the mother and others have to be experienced to bring the brain up to psychological