Last week I had the good fortune of participating in a stimulating workshop on protolanguage organized by Dorit Bar-On and Mitch Green at the University of Virginia. Thanks to the organizers for their excellent work.
I was asked to comment on a paper by Bruno Galantucci (BG) et al. on a new discipline I never encountered before: experimental semiotics (ES). ES asks people to communicate in novel ways under various constraints and studies the novel communication systems that emerge in those contexts.
Experimental Semiotics (ES) looks like an innovative and promising way to investigate many features of communication systems, including their acquisition, structure, and evolution.
Two questions that are of special interest to philosophers and to those interested in the origin of language are what the nature of language is and whether language is continuous or discontinuous with other (especially non-human) communication systems.
As Bruno Galantucci (BG) pointed out, ES provides evidence that “combinatoriality” (recurrence of basic forms) emerges during a semiotic coordination game when the communication system fades quickly and compositionality (complex expressions take their meaning from the meanings of their parts) emerges during a semiotic matching game when players have to often encode novel meanings.
I pointed out that human language is productive, i.e. it can generate infinitely many recursive structures from finitely many primitives. Combinatoriality defined simply as recurrence of basic forms does not seem to be enough for true productivity. True productivity requires a grammatical division of words into types (noun, verb, etc.) and a recursive syntax that determines which combinations of primitives are well formed (sentences) and which combinations are not. A relevant question is whether any of the ES games that BG describes exhibit “combinatoriality” with enough structure (rules) to amount to true productivity.
A similar point applies to compositionality. True linguistic compositionality comes hand in hand with true productivity, which requires a grammar and a recursive syntax. A relevant question is whether any of the ES games that BG describes exhibit full-blown linguistic compositionality.
It may well be that relatively simple ES games produce communication systems with some degree of “combinatoriality” and a simple form of compositionality. But that is not enough for these communication systems to be of the same kind as natural language. Perhaps the communication systems that ES has studied so far are more akin to a protolanguage than a full blown language. If any ES games do exhibit true productivity and compositionality, then perhaps they should be considered novel languages on a par with natural languages.
Thinking about ES was fun and suggested an experiment that as far as I know has not been tried. I called it a Gavagai Game (in honor of Quine, who thought that reference is indeterminate and therefore we could never be sure that someone who utters “gavagai” while pointing at a rabbit means rabbit rather than undetached rabbit parts, etc.). Two or more people who speak very different languages (and perhaps come from different cultures) are forced to communicate under various conditions, without restrictions to a particular medium of communication or communication rules. It would be interesting to see what kind of communication system they would develop (would it be a pidgin?), what their first steps would be, how their communication system would evolve, how close to a language it would be, and how they would reach agreement as to what they are referring to (to the extent that they do). If anyone has the time and resources to try this…