Discrete and systematic communication in a continuous signal-meaning space

Human language displays both discreteness (the segmentation of continuous sensory information into distinct categories) and systematicity (the alignment of these categories into structured, meaningful patterns). These properties are crucial for language's flexibility and expressivity, but the cognitive biases driving their emergence remain unclear. To address this, we designed a real-time communication game where participants developed auditory signaling systems, generalizing from a small number of learned signal-meaning mappings to communicate about a continuous color space. The emergent communication systems exhibited both discreteness and systematicity. Systematicity, in particular, predicted successful communication. Our results suggest that cognitive biases toward non-arbitrary meaning-form associations may facilitate the development of successful cooperative communication.