noun

• (psychology) The process whereby the ideas of another are unconsciously incorporated into one's own psyche.
  "Sometimes the attempt was made to reduce the inner to the outer world (Condillac, Mach, Avenarius, materialism); sometimes the outer to the inner world (Descartes, Berkeley, Fichte); sometimes the sphere of the absolute to the others (e.g., by trying to infer causally the essence and existence of something divine in general); […]; sometimes the general differentiation of subject and object to pregivenness of the co- or 'fellow-man', to whom an environmental element—as, for instance, 'this tree' — is supposed to be introjected, followed by subsequent introjection by the observer to himself (Avenarius); sometimes one's own body to a merely associative coordination of the self-perception of the own self and organ sensations with the own body as perceived from outside."