In a pair of 14 year old DZ twins of different sexes, a particularly profound emotional separation becomes manifest during childhood.
The twins come from a family whose members are considerably introvert, and where very few exchanges of emotional manifestations take place. The male twin offers a more fundamental alteration of personality, and his emotional control is often overwhelmed by antisocial tendencies of relative frequency. In accordance with her family surroundings his twin, instead, possesses a particularly rigid and severe moral conscience.
The twins are spiritually separated when at the age of eight and nine years, the boy attempts certain sexual approaches on the little girl. At first the child consents, but gradually a most intense feeling of guilt rises up in her, which is accompanied by an aversion, rapidly changing into invincibile hatred towards her brother, whom she fears will subject her to further sexual practises.
Notwithstanding the preponderance of the sexual factor, the antisocial behaviour of the boy, also contributed to a certain extent to this separation.
From a psychoanalytic point of view, the girl's behaviour, characterised by a typical inversion of feelings could be in- terpreted as a reaction formation.
As the boy has been classified from a psychiatric diagnosis as bearing a psychopathic personality which occupies a position between neurosis and psychosis, the eventual possibility of a certain degree of familiar and social adjustement is not to be excluded.