The nature of young children's communicative environment has been central to theoretical debates about the importance of innate and environmental factors in the development of communication and language. In this paper, we explore aspects of the communicative development and environment of young children growing up in two very different cultures, one in a village of eastern Nepal and the other in a rural area of Western Germany. We analysed longitudinal video recordings of 6 children from each culture in naturalistic settings, at age-matched time points over a period of 8 months. Four children were 8 months old at the outset of the study, 4 were 2 years and 2 months old, and 4 were 3 years old. There were major differences between cultures in the number of adults and children present during the recordings, with other children playing an increasingly important role for the older children in the Nepal recordings. We found no difference between cultures in the onset of pointing and imitation or of reaching, requesting and offering, indicating that these behaviours may be part of a human-specific timetable for socio-cognitive development. We also found that imitation by both the target children and those around them was strictly limited to the youngest group in both cultures. This suggests that imitation may be very important for early development in the prelinguistic phase, while around the age of 2, with the child's developing competence, other ways of interacting take over. The theoretical implications of our results are discussed with reference to the roles of child-intrinsic and environmental factors in the developmental process.