We address a gap in research on the bi-directional effects of language on thought and thought on language, and the developmental pathways that transmit interactions between language and cognition from one generation to the next. The significant empirical advances we propose will result in a unified, cross-disciplinary theory which addresses language diversity through the dynamic interaction of language and cognitive systems across languages and cultures. To this end, we select shape as a core spatial property of entities in the physical world of things which determines bodily action on objects. The abstract properties of shape are codified in multiple ways in the world’s varied languages, including spoken and signed languages – in object and category labels and their organization into classes of categories, spatial prepositions, verbs, and quantifying expressions. Visual shape perception and shape representation in early perceptual and cognitive development are inherently intertwined and interdependent with early language acquisition. Children on atypical developmental trajectories show a cascade of disrupted development in both shape perception and language that can have substantial life-long consequences. Despite this compelling evidence of the pervasiveness of shape, no theoretical account has been offered to explain its nature as a system, neither has this topic been approached integrating evidence and methodologies across disciplines. The main goal of the current endeavor is to provide such an account from the point of view of systems theory and aligning methodologies across vision research, cognitive development, theory of language and language typology and sign language. Our premise is that shape holds a privileged status in human representational systems – in perceiving, using and reasoning about objects and in organizing the structures of the world’s languages and, as such, is key to understanding human intelligence and its developmental trajectories.