What can language creation tell us about language evolution?

How did the languages we use today come about? One way to make this problem more tractable is to think about language, not as a single entity but as a compilation of properties. Biological evolution may have resulted in the creation of some properties of language. However, cultural evolution, which relies on changes introduced by successive generations of users and is quicker than biological evolution, may also be responsible for the introduction of properties into language. Although it is difficult to distinguish linguistic properties introduced through biological evolution from those introduced through cultural evolution, one way to approach this problem is to observe a modern-day child who has not been exposed to a usable model for language. Despite the lack of a language model, a child in this situation can communicate and uses gestures to do so. These gestures, called homesigns, contain many, but not all, of the properties found in natural language. I suggest that the properties of language found in homesign are good candidates for linguistic properties that arose through biological evolution. By contrast, the properties not found in homesign are good candidates for linguistic properties that were introduced into language through cultural evolution. (PsycInfo Database Record (c) 2025 APA, all rights reserved).