Cognitive scientists differentiate the “minimal self” – subjective experiences of agency and ownership in our sensorimotor interactions with the world – and the “narrative self” that encompasses those beliefs about the self that are sustained over time. How exactly moment-to-moment experiences are integrated into narrative beliefs, however, remains an open question. We administered a battery of sensorimotor tasks and surveys to index subjects’ (n = 195) propensity to classify stimuli as self-caused and their metacognitive monitoring of such agency judgements, and we compared these behavioral metrics to trait-level beliefs about their own agency. Subjects who were less sensitive to sensory control cues in the sensorimotor tasks also reported lower trait-level agency beliefs. Importantly, however, this relationship all but disappears when controlling for metacognitive accuracy. These results suggest narrative beliefs about self-agency are not just the sum of individual experiences of self-causation but rather the product of a metacognitively-driven integration process.