The ensemble of partial drives directed toward the mother, once she is perceived as an object that is differentiated from the self, is accompanied by hostile rivalry toward the father. This oedipal rivalry is extended to the hostile relationships that occur among siblings.
In "Neurotic Mechanisms in Jealousy, Paranoia and Homosexuality", Sigmund Freud posited an analogy between this mechanism and the process that is the basis for social bonds: "In both processes, there is first the presence of jealous and hostile impulses which cannot achieve satisfaction; and both the affectionate and the social feelings of identification arise as reactive formations against the repressed aggressive impulses."
Putting himself in the place of this other, the subject imagines himself as being dispossessed of a source of enjoyment (jouissance) that tolerates no sharing. The subject's hatred is all the stronger because unconsciously, this struggle is for possession of an object that bears the narcissistic illusion of perfect continuity between self and other. The destructiveness of the tendency away from differentiation is thus transformed into hatred and suspended through triangulation.