by Albert Major
Title: The Faculty of Language: What Is It, Who Has It, and How Did It Evolve?
Authors: Marc D. Hauser, Noam Chomsky, W. Tecumseh Fitch
This paper asks what the core components of the human language faculty are, how they evolved, and which aspects are uniquely human. The authors distinguish between the Faculty of Language in the Broad Sense (FLB)—which includes sensory-motor and conceptual-intentional systems—and the Faculty of Language in the Narrow Sense (FLN), which they argue consists solely of recursion: the ability to generate infinite expressions from finite elements. The article integrates insights from linguistics, neuroscience, psychology, and evolutionary biology, using comparative studies of animals and humans as the primary evidence base to trace the evolutionary pathways of language-related capacities.
Experimental Setup (Described Studies and Evidence)
Instead of a single experiment, this review synthesizes dozens of studies comparing humans to nonhuman animals—such as primates, birds, and dolphins—on their ability to process communication signals, learn vocalizations, and represent abstract concepts. Recursion, vocal imitation, and intentional communication were key capacities tested. For example, tamarin monkeys could learn finite-state grammars (e.g., ABAB), but failed to learn phrase-structure grammars (e.g., AⁿBⁿ), which human adults mastered easily. EEG or fMRI were not directly used in the studies reviewed, but comparative behavioral evidence and neurobiological parallels (e.g., mirror neurons, vocal imitation circuits) were emphasized.
When animals like chimpanzees or parrots were taught symbol systems, they showed limited combinatorial flexibility and no spontaneous recursion, unlike human children, who rapidly generalize once they grasp the recursive principle. Birdsong learning and vocal imitation in dolphins paralleled human speech development in some respects but lacked full FLN-level syntax.
In language, recursion is the ability to embed structures within similar structures—like a sentence inside another sentence—allowing us to build infinitely long and complex expressions from a limited set of rules. It’s what lets us say things like “She thinks that he knows that I lied.”
Key Results and Interpretation
Animals share many FLB components (e.g., sound discrimination, conceptual representation), but only humans exhibit FLN capacities. The key innovation is recursion, which is missing or extremely limited in nonhumans. For instance, tamarins could not generalize recursive rules, even after extensive training, suggesting a cognitive boundary. Conversely, human infants acquire recursive structure rapidly and spontaneously, indicating a domain-specific computational capacity. Interestingly, recursion may not have evolved for language, but rather for other tasks like navigation or numerical reasoning, and only later got co-opted into communication.
What You Should Know