The function of self-preservation develops gradually in the preoedipal and oedipal phase as functioning according to the pleasure principle is gradually replaced by the reality principle and the child takes over the self-protective function from his parents.

I gave examples which highlight age-characteristic factors leading to accidents. Among the factors resulting in accidents are: the tendency to express mental conflict in bodily terms may still be found in the early preoedipal phase of development; anal-sadistic conflicts, age-specific castration anxiety, in combination with the defense mechanism of turning aggression against the self, the mode of expression in action rather than in fantasy or thought, may result in accidents. In adolescents, the same result may come about through the dramatization of sexual fantasies, for instance, together with exhibitionism and sudden, often deep regression.