In the past, researchers have focused mainly on the effects and consequences of self-awareness; however, they have neglected a more basic issue pertaining to the specific mechanisms that initiate and sustain self-perception. The author presents a model of self-awareness that proposes the existence of 3 sources of self-information. First, the social milieu includes early face-to-face interactions, self-relevant feedback, a social comparison mechanism that leads to perspective taking, and audiences. Second, contacts with objects and structures in the physical environment foster self-world differentiation in infants; this environment also contains self-focusing and reflecting stimuli, such as mirrors and video cameras. Third, the self can develop bodily awareness through proprioception and can reflect on itself using imagery and inner speech. Furthermore, self-awareness is mainly mediated by the prefrontal lobes. The author establishes various links among these different neurological, social, ecological, and cognitive elements of the model.