Intentionality, the ability to read intentions underlying actions, is a core component of folk understanding of mind that is foundational for much of social cognition. Inferences about intentionality permeate perception, prediction, and explanation of behavior; interpretation of linguistic utterances and emotional expressions; and the ability to successfully communicate and collaborate with others. Moreover, intentionality drives moral judgments, attributions of praise and blame, and systems of jurisprudence. Arguably, intentional understanding is as evolutionarily significant as fundamental conceptions of time, space, and [Page 1179]physical causality. This entry describes contrasting views of intentional understanding, the development of intentional understanding in infancy and early childhood, and intentional understanding later in life.