A common form of embodied social engagement involves acting as an ensemble, with all participants aware of each other and mutually engaged. In this naturalistic comparative study, we term this kind of triadic socio-cognitive activity ‘fluid collaboration’. Fluid collaboration occurs when participants establish the pace of ensemble activity mutually, with their moves flexibly adjusted and responsive to one another and to the demands of their shared endeavors. The moves of a fluidly collaborating ensemble depend on each other and might be described as harmonious. This kind of ensemble behavior appears to be the activity of “one organism with many limbs”. Utilizing a micro-analytic qualitative method, our finding of cultural differences in fluid collaboration relates to previous ethnographic and comparative work involving patterns of collaborative activity in Indigenous and Indigenous heritage communities in the Americas.