Cross-linguistic zero-shot communication via ad-hoc pseudowords

In verbal communication, speakers must encode meanings into signs such as words. Within a given language community, the correspondence between word forms and meanings can become conventionalized. However, speakers from different language communities cannot rely on these shared conventions. Here, we investigate whether purely verbal communication using single words is still possible in such a context, enabled by generalized form-meaning mappings. In a pre-registered experiment, we presented Italian speakers with words and instructed them to come up with corresponding German translations. The resulting German-like pseudowords were then shown to German speakers, who were asked to guess the original words. Supporting our hypotheses, results showed that the German participants' guesses were semantically closer to the original words than to randomly selected control words. These findings highlight the remarkable human ability to spontaneously create and interpret meaningful signals, even across language boundaries and without relying on an established mutually-known lexicon.