The article reviews evidence that infants in their second year of life can attribute false beliefs to others, challenging the traditional view that this ability emerges around age 4. Recent studies using spontaneous-response tasks, such as violation-of-expectation (VOE) and anticipatory-looking (AL) tasks, suggest that infants can understand false beliefs about location, identity, and perception. These findings are robust across different tasks and agents, indicating a sophisticated understanding of mental states. The authors discuss alternative interpretations, such as associations and unusual events, and highlight the limitations of elicited-response tasks, which may be too complex for young children. They propose a "response account" to explain why young children fail at elicited-response tasks, suggesting that the brain's ability to execute multiple processes simultaneously is not yet fully developed. The article concludes by outlining several outstanding questions and directions for future research.The article reviews evidence that infants in their second year of life can attribute false beliefs to others, challenging the traditional view that this ability emerges around age 4. Recent studies using spontaneous-response tasks, such as violation-of-expectation (VOE) and anticipatory-looking (AL) tasks, suggest that infants can understand false beliefs about location, identity, and perception. These findings are robust across different tasks and agents, indicating a sophisticated understanding of mental states. The authors discuss alternative interpretations, such as associations and unusual events, and highlight the limitations of elicited-response tasks, which may be too complex for young children. They propose a "response account" to explain why young children fail at elicited-response tasks, suggesting that the brain's ability to execute multiple processes simultaneously is not yet fully developed. The article concludes by outlining several outstanding questions and directions for future research.