Gottlieb promoted the value of a developmental psychobiological systems approach to the study of human development. This approach recognizes the importance of comparative, animal-based research to advancing our understanding of the complexities and dynamics of the process of development. The major contribution of animal developmental studies is their provision of food for thought (hypotheses, not facts) about human development and general principles of development. Here we briefly describe how, guided by Gottlieb's pioneering vision, we have utilized coordinated studies of non-human animal and human infants to begin to identify patterns of selective attention and perceptual processing that are common across species in early development. Our converging findings highlight the importance of multimodal (intersensory) redundancy in guiding and constraining early perceptual learning in avian and mammalian species.