Comparative perspectives on mother-infant communication in primates: Are humans unique?

Human cognition is often claimed to be unique within the animal kingdom. Comparing infant development across primate species to examine maternal interactions is a promising approach to understanding potential cognitive differences between humans and other primates. In this review, we focus on the communicative interactions between mother-infant dyads in nonhuman primate species and humans from different cultural backgrounds, as these interactions are crucial for infant survival, the formation of emotional bonds, and cognitive development. We explore different aspects of mother-infant communication, including the dynamics of these interactions, intra-species variation in mother-infant communication across groups and individuals, and the potential role of other caregivers. Additionally, we address current methodological challenges, such as the underrepresentation of multimodal approaches in studying mother-infant communication and the need for standardized methods to facilitate systematic comparisons across species and study populations. We conclude that it is currently premature to answer the question if human mother-infant communicative interactions are fundamentally different as compared to those of other primates, as critical knowledge gaps must be filled first. We address some of these gaps and propose key aspects that need to be examined to develop a more comprehensive understanding of mother-infant communication across primates and its potential influence on infants' developmental trajectories.