Intersubjectivity is activity plus accountability

Intersubjectivity is central to human social life. We argue that the uniquely human form of intersubjectivity can be defined as the combination of activity and accountability. It consists of more than merely sharing knowledge or perspectives. Intersubjectivity arises through human social activity in which people pursue shared goals and where their respective contributions are observable and subject to public evaluation. We also argue that human intersubjectivity is intertwined with language, in two ways. First, some form of intersubjectivity is necessary for language to have evolved in our species in the first place. Second, language then transforms the nature of our intersubjectivity, through its definitive properties of inferentially articulated description, self-reflexivity, and productive grammatical flexibility. Social accountability—the bedrock of society—is grounded in this linguistically transformed kind of intersubjectivity. We illustrate these points with reference to data from two relatively simple examples: two-person timber sawing and two-person mat-weaving.