Some habits are vital to who we are in that they shape both our self-perception and how we are seen by others. This is so, I argue, because there is a constitutive link between what I shall call ‘identity-shaping habits’ and narrative agency. Identity-shaping habits are paradigmatically acquired and performed by persons. The ontology of personhood involves both synchronic and diachronic dimensions which are structurally analogous to the synchronic acquisition and the diachronic performance of habits, and makes persons distinctly suitable (...) to being shaped by habits. Since habits differ vastly in their scope, I develop a conceptualization that carves out defining features of identity-shaping habits. Such habits, I venture, fundamentally alter a person’s embodiment such that the alterations to their psychological and physiological make-up vitally inform their persistence—if not metaphysically, then at least practically by crucially shaping one’s narrative agency. (shrink)