How to explain the ontogenetic origin of sociality in human infants without invoking innate cognitive phenomena (grammar, language for thought, sociality, and so on)? My research will describe the biological origin of sociality in infants without assuming any preexisting, innate cognitive or social abilities. I implicitly counter cognitive science claims both by argument and detailed a Conversation Analysis (CA): 1) Employing claims from the philosophy Wittgenstein (and secondarily L. Vygotsky and S. Weil), I argue that cognition is not necessary for social interaction to exist and/or ensue; 2) I demonstrate the claims in ´1´, through a CA of infant/caregiver interaction in various languages; 3) I demonstrate how Wittgenstein´s claims, that sociality, in the form of turn-taking, is built on infants´ natural (biological) reactions; 4) I will also demonstrate that infants´ biological reactions occasion and are occasioned by caregivers’ interactional turns, allowing interaction to be orderly, and thus grounding infant sociality. 5) The grounding of infant sociality provides the ground for general society. In CA, a strong claim exists that the primordial site for sociality is social interaction (Schegloff 2007). This claim constitutes my starting point. It begs the question however, of what is the (ontogenetic, not phylogenetic) origin of sociality for individuals. The unreflective answer has been interaction, or ´talk´ as the CA people claim. However, the very existence of CA as an research methodology assumes the existence of talk or conversation as a constituent part of interaction. Young infants (0-5 months in my study), by definition, cannot talk, invoking additional problems and questions for CA methodology. If infants cannot talk, and if talk is the primordial site of sociality, then how does sociality originate in individual infants? Of course the nativists/innatists such as Chomsky, Fodor, Pinker, and many others, offer the answer that apriori cognitive phenomena exist, such as innate grammar, which allows society and language to develop. On the other side stand the behaviorists, who claim that society or social structure is merely a complex form of a child imitating adult behaviors. Both of these positions are untenable from my (Wittgensteinian/CA) research point of view. Employing Wittgenstein´s claims as the ground of this research, I focus on infants’ biological reactions, crying, gazing, drinking bottle, and so on, as behaviors that are reacted to by caregivers, and are at crucial times by the caregiver, treated as if the infants´ biological reactions are legitimate social interactional turns, as if infants are mature social members. In acting so, caregivers create criteria (acting as if) for the legitimacy of the infants´ turns. The preliminary results of my research so far seem to demonstrate that it is indeed these infant biological reactions and a particular orientation to same, by caregivers, which seems to ontogenetically initiate sociality in infants. I will examine if and how turn-taking and sequencing exist and continue in infant/caregiver interaction, and how these interactional devices foster infant sociality, which then presumably fosters the learning of language.