How we change what others think, feel, believe and do
We are interpellated, or 'hailed' into subject positions. Thus a policeman who calls to us is interpellating us into a subject position of subjugation by the state. For this to work, we must recognize and accept this subject position.
The process of identification thus creates identity. You identify me and I become that me that you have identified.
A strange fact is that we seem to recognize ourselves when we are hailed. I know that it is me who is being called as I unconsciously accept the subject position. It is as if we had always-already been there. The apparent freedom with which we accept the position only serves to cement us further into it.
Interpellation can be considered as 'recruitment' as it invites a person into a subject position. When they do so, the consistency principle then leads them into a cycle of investment whereby they bond their sense of identity both to the subject position and also the underlying ideology.
Interpellation was described by Althusser in his reinterpretation of Marxism and the position of the subject. He explained how Ideological State Apparatuses interpellated the subjects into ideological positions.
The position we take is relative to a more significant, superior and central 'Other Subject', whether it is the state, God or some other ultimate authority. The person-as-subject is thus defined by the other and the person recognizes themselves as an image or reflection of the Other. This allows the person to claim the quality of the Other but also requires subjugation to the Other. To deny the Other is to deny one's own existence.
Thus we are become trapped within an ideology that creates an Other and hence the person.
Althusser uses Lacan's mirror phase to highlight how subjects are interpellated, but does not recognize the critical misrecognition that Lacan highlights. Althusser has also been criticized for how his subject is magically created of nowhere (what is there before the subject?).
Althusser, L. (1989). 'Ideology and ideological state apparatuses' in Lenin and Philosophy and other Essays. London: New Left Books pp 170-86