Final answer:
The feature of human language that enables the creation of an infinite number of new messages is called its generative capacity. This capacity is embedded in the structural rules of language and is a product of unique biological adaptations in humans.
Step-by-step explanation:
The feature of human language that allows for an infinite capacity for generating new messages is known as its generative capacity. At the core of this infinite potential for human communication are structural rules that instruct how sounds, signs, words, and phrases can be combined to form meaningful utterances. These rules dictate aspects of language such as word order, singular versus plural nouns, and verb tenses signaling past, present, or future actions. While advanced animal communication systems exhibit some systematic rules, they are far more limited than human language, which is uniquely open-ended and allows for endless innovation and variety.
Strong biological underpinnings contribute to the human capacity for language, including specialized structures in the throat, brain, and genetic makeup. This capacity is evident from birth, as babies can learn any language through passive exposure. Language acquisition not only facilitates communication but also supports complex reasoning and social interaction, contributing to the development of human culture. Moreover, our language continues to evolve, incorporating new concepts and terms as society changes, showcasing its dynamic and generative nature.