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Comment by jampekka | Hacker News Reader

The poverty of the stimulus (POS) argument is that "evolutionary pre-training" in the form (recursive) grammar is fundamentally required and can not be inferred from the stimulus.

The argument is based on multiple questionable assumptions of Chomskian linguistics:

- Humans actually learn grammar in the Chomskian way - Syntax is separate from semantics, so only language (utterances) can be learned from uttrances, and not e.g. what is seen in the environment - At least in the Gold's formalization of the argument language is learned only from "positive examples", so e.g. the learner can't observe that some does not understand some utterance

One could argue for a (very) weak form of POS that there has to be some kind of "inductive bias" in the learning system, but this applies to all learning as shown by Kant. The inductive bias can be very generic.

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>At least in the Gold's formalization

It seems to be a persistent myth (possibly revived more recently due to Norvig?) that Chomsky's POS argument has some interesting connection to Gold's theorem. The two things have only a very loose logical connection (Gold's theorem is in no sense a formalization of any claim of Chomsky's), and Chomsky himself never based any of his arguments for innateness on Gold's theorem. Here is a secondary source making the same point (search for 'Gold'): https://stevenpinker.com/files/pinker/files/jcl_macwhinney_c...

The assumption that syntax is 'separate from semantics' also does not figure in any of Chomsky's POS arguments. Chomsky argued that syntax was separate from semantics only in the fairly uncontroversial sense that there are properly syntactic primitives (e.g. 'noun', 'chain', 'c-command') that do not reduce entirely to semantic or phonological notions. But even if that were untrue, it would not undermine POS arguments, which for the most part can be run without any specific assumptions about the syntax/semantics boundary. Indeed, semantic and conceptual knowledge provides an equally fertile source of POS problems.

Yeah, I don't necessarily buy the whole Chomskian program. I'm willing to be persuaded that the reason kids learn to speak despite their individual poverty of stimulus is that there was sufficient empirically experience stimulus over evolutionary time. The Chomskian grammar stuff seems way too Platonic to be a description of human neuroanatomy. But be that as it may, it's clear the stimulus it takes to train an LLM is orders of magnitude greater than the stimulus necessary to train an individual child, so children must have a different process for language acquisition.

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