This qualitative multi-case study explored the social exchanges and responsive connections between infants and their infant childcare teachers within a group care context. Infants' naturally occurring behaviours were videotaped purposefully at two separate time points, near the end of their first year and approximately six months later. Findings revealed various ways that infants and their teachers were "in synch" or "out of synch" within everyday practice. Infant teachers were "in synch" with infants when they established reciprocal and meaningful joint understandings that were differentiated according to infants' individual and changing developmental needs. Infant teachers could also be "out of synch" with an infant when they missed the infant's subtle cues or an infant did not easily adapt to caregivers' expectations and styles. Our findings urge teachers and teacher educators to think deeply about the meaning and complex nature of high quality, responsive caregiving within infant childcare environments.