This is likely a response to https://news.ycombinator.com/item?id=10612447

The Nicaraguan Sign Language (ISN)[0] is an incredibly interesting phenomenon, demonstrating at least that humans will find a way to use language regardless of whether or not a culture of language exists around them, provided that they have the opportunity to do so early enough. Does it confirm that language capacity is innate, that Chomsky's "language organ" (I'm sure he rues the day he ever used that phrase; he's been trying to clarify what he meant for sixty years) exists? It's not the only occurrence of this sort that is known but it's the first that was documented as it happened. (Hawaiian Creole English also arose among children in relatively recent times, but its documentation is oblique, consisting mostly of recorded complaints about a new and obviously unacceptable manner of speaking among "today's youth".)

It's important to keep in mind that these kids were not taught the language, they developed it on their own because they had no real language. They had ways of communicating, of course, through mimicas, but fundamentally humans are unsatisfied with merely making their needs known. Language—the movement of thought from one skull to another—is a huge part of what we are.

It's a fascinating story, but there are better tellings of it.

[0] https://en.wikipedia.org/wiki/Nicaraguan_Sign_Language

Language is probably the most important point of distinction between humans and all other animals: no animal has anything quite like it. Language is intimately connected with symbolic reasoning, and enabled the social coordination and shared learning that underlays our contemporary technology and success. But where does language come from?

Researching language is very difficult, however, due to the ethical issues of researching human cognition and the difficulty of studying socially learned behaviors of WEIRD college students in contrast to hunter-gatherer infants. So you have had people trying to reason from the examples of severely brain-damaged adults, horrifically abused children, or experiments conducted by temporarily paralyzing peoples' brains.

The amazing thing about NSL is that it is a well-documented example of linguogenesis: A non-linguistic human community essentially developed a new language and developed it to a high degree of sophistication within a scant few generations. This is not merely creolization, or something that was discovered after the fact. People have been able to document the increasing sophistication of the grammar with every class.

Understanding that different people have a different perspective on the world (or at least, grasping that on a gut level) is a key milestone in developmental psychology that normally happens as a very young child (<5yo). This is the first time that this has been definitively tied to language. 30yo's without adequate language to express these concepts were unable to understand them - not just express them.