Intersubjectivity, the coordination of people’s beliefs and actions, is central to human psychology and society. However, a legacy of Cartesian dualism has fragmented research along two dimensions (psychological vs. interpersonal; structural vs. interactional). This fragmentation obscures how the psychological and interpersonal aspects of intersubjectivity mutually reinforce one another. I argue that, despite epistemological differences, these literatures converge on recurring formal correspondences: three recursive levels of perspective-taking (direct, meta, meta-meta), three-turn interaction sequences (initiation-response-feedback), and triadic self-other-object relations. Building on these convergences, I propose a minimal model of dialogical intersubjectivity that entails three-turn social interaction generating and sustaining three levels of perspective-taking. Each turn can take the prior turn as its object, thereby adding a level of perspective-taking. The exchange of turns rotates participant positions (e.g., speaker becomes listener), introducing an external vantage point on the prior contribution, thus ratcheting up intersubjectivity by one level. This model explains how implicit assumptions become explicit and how social interaction patterns give rise to psychological processes.
