The document summarizes theories on identity by Althusser, Stryker, and Marcuse. Althusser's theory of interpellation proposes that individuals absorb their identity from dominant ideologies through uncritical consumption of media texts. Stryker's identity salience hierarchy refers to identities ordered by importance, where more salient identities are more likely to be invoked. Commitment can change an identity's position. Marcuse argues that identity formation is constrained by consumerism and technology, leaving no room for inner self-development and instead creating false needs through advertising.