International audience This book focuses on the variability of metacognitive skills across cultures. Metacognition refers to the processes that enable agents to contextually control their first-order cognitive activity (e.g. perceiving, remembering, learning, or problem-solving) by monitoring them, i.e. assessing their likely success. It is involved in our daily observations, such as “I don’t remember where my keys are,” or “I understand your point.” These assessments may rely either on specialized feelings (e.g. the felt fluency involved in distinguishing familiar from new environments, informative from repetitive messages, difficult from easy cognitive tasks) or on folk theories about one’s own mental abilities. Variable and universal features associated with these dimensions are documented, using anthropological, linguistic, neuroscientific, and psychological evidence. Among the universal cross-cultural aspects of metacognition, children are found to be more sensitive to their own ignorance than to that of others, adults have an intuitive understanding of what counts as knowledge, and speakers are sensitive to the reliability of informational sources (independently of the way the information is linguistically expressed). On the other hand, an agent’s decisions to allocate effort, motivation to learn, and sense of being right or wrong in perceptions and memories (and other cognitive tasks) are shown to depend on specific transmitted goals, norms, and values. Metacognitive variability is seen to be modulated (among other factors) by variation in attention patterns (analytic or holistic), self-concepts (independent or interdependent), agentive properties (autonomous or heteronomous), childrearing style (individual or collective), and modes of learning (observational or pedagogical). New domains of metacognitive variability are studied, such as those generated by metacognition-oriented embodied practices (present in rituals and religious worship) and by culture-specific lay theories about subjective uncertainty and knowledge regarding natural or supernatural entities.