This essay argues that a unifying theme based on developmental psychology underlies Annette Michelson’s disparate writings on cinema, ranging from science fiction to Soviet Cinema to the American avant-garde. Emphasizing Michelson’s repeated recourse to the work of Jean Piaget on cognitive development, I argue thata central criteria of assessment involved the “mental age” of the film: whether it followed the terms of an “adult” logic of mental possibility or regressed into childhood attachments to the given. Drawing on Michelson’s key writings from the 1970s and 1980s, I argue that her developmentalist account of cinema generates a complex and dense account of the epistemic and aesthetic possibilities of time and temporal organization.