The article examines how infants are first permeated by culture. Building on Thibault (2000), semiogenesis is traced to the joint activity of primary intersubjectivity. Using an African example, analysis shows how--at 14 weeks--an infant already uses culturally specific indicators of "what a caregiver wants." Human predispositions and the mother's enactment of cultural processes enable the child to give joint activity a specific "sense." Developmentally, the child prods the caregiver to shaping his or her actions around social norms that transform the infant's world. This nascent lopsided relation is probably necessary for learning to talk. Acting with its mother, the baby's full-bodied activity uses adult "understanding" in ways that are cultural, contingent, and indexical. Infant activity is already semiotic. (Contains 3 tables and 8 footnotes.)