system
Given the following post, respond as if you're commenting on Reddit:
human
Does a language's complexity (grammar, pronunciation, vocabulary size, etc.) follow a standard curve over time?

As a language develops, matures, and eventually fades away or morphs into new distinct languages, does it follow a standard pattern in terms of linguistic complexity?

Is it true that mature languages simplify themselves over time, with rules for grammar, spelling, and pronunciation becoming more relaxed? If so, why do languages get complex in the first place?
gpt
There aren't "mature" and "immature" languages. As far as linguists are concerned, all languages (barring a few exceptions like creoles and some sign languages) are equally "mature". (Edit: to clarify this a bit, we have no idea how old most languages are. Excepting creoles and some sign languages, their origins are shrouded in the depths of human prehistory. We have the comparative method, and it's powerful, but it only gets us so far before it becomes incredibly unreliable.)

As to whether languages get 'more' or 'less' complex over time, that's difficult to answer for a few reasons. There is no single measure of linguistic complexity. We can, perhaps, quantify complexity in a part of a language (for one such approach, see Ackerman and Malouf 2013), but not for a whole language.

There are a lot of different pressures that act on language users. Speakers are generally lazy, and want to use the minimum of effort to get their point across. Listeners, on the other hand, want unambiguous and clear speech so they don't have to spend a lot of time processing the signal. One very popular (though controversial) framework these days is called Optimality Theory, and attempts to integrate these pressures into linguistic description.