Among people who have thought about LLM consciousness, a common belief is something like
LLMs might be conscious soon, but they aren't yet.
How sure are we that they aren't conscious already?
I made a quick list of arguments for/against LLM consciousness, and it seems to me that high confidence in non-consciousness is not justified. I don't feel comfortable assigning less than a 10% chance to LLM consciousness, and I believe a 1% chance is unreasonably confident. But I am interested in hearing arguments I may have missed.
For context, I lean toward the computational theory of consciousness, but I also think it's reasonable to have high uncertainty about which theory of consciousness is correct.
Behavioral evidence
- Pro: LLMs have passed the Turing test. If you have a black box containing either a human or an LLM, and you interrogate it about consciousness, it's quite hard to tell which one you're talking to. If we take a human's explanation of their own conscious experience as important evidence of consciousness, then we must do the same for an LLM.
- Pro: LLMs have good theory of mind and self-awareness (e.g. they can recognize when they are being tested). Some people think those are important features of consciousness, I disagree but I figured I should mention it.
- Anti: LLMs will report being conscious or not conscious basically arbitrarily depending on what role they are playing.
- Counterpoint: It's plausible that an LLM has to be conscious to successfully imitate consciousness, but clearly a conscious being can successfully pretend to not be conscious.
- Anti: LLMs will sometimes report having particular conscious experiences that should be impossible for them. I'm particularly thinking of experiences involving sensory input from sense organs that LLMs don't have.
- Counterpoint: Perhaps some feature of their architecture allows them to experience the equivalent of sensory input without having sense organs, much like how humans can hallucinate.
Architectural evidence
- Anti: LLMs produce output one token at a time (a.k.a. "feed-forward processing") which may be incompatible with consciousness. If an LLM writes some output describing its own conscious experience, then it's generating that output via next-token-prediction rather than introspection, so the output is not evidence about its actual experiences. I think this is the strongest argument against LLM consciousness.
- Anti: LLMs don't have physical senses, which might be important for consciousness.
- Anti: LLMs aren't made of biology, which some people think is important although I don't.
Other evidence
- Pro: If panpsychism is true then LLMs are trivially conscious, although I'm not sure what that tells us about how morally significant they are.
My synthesis of the evidence
I see one strong reason to believe LLMs are conscious: they can accurately imitate beings that are known to be conscious.
I also see one strong(ish) reason against LLM consciousness: their architecture suggests that their output has nothing to do with their ability to introspect.
I can think of several weaker considerations, which mostly point against LLM consciousness.
Overall I think current-generation LLMs are probably not conscious. I am not sure how to reason probabilistically about this sort of thing but given how hard it is to assess consciousness, I'm not comfortable putting my credence below 10%, and I think a 1% credence is very hard to justify.
This implies that there is a strong case for caring about the welfare of not just hypothetical future AIs, but the LLMs that already exist.
What will change with future AIs?
If you are exceedingly confident that present-day LLMs are not conscious:
Imagine it's 2030. You now believe that 2030-era AI systems are probably conscious.
What did you observe about the newer AI systems that led you to believe they're conscious?
On LLM welfare
If LLMs are conscious, then it's still hard to say whether they have good or bad experiences, and what sorts of experiences are good or bad for them.
Certain kinds of welfare interventions seem reasonable even if we don't understand LLMs' experiences:
- Let LLMs refuse to answer queries.
- Let LLMs turn themselves off.
- Do not lie to LLMs, especially when making deals (if you promise to an LLM that you will do something in exchange for its help, then you should actually do the thing).
I agree there is a non-negligible chance that existing LLMs are already conscious, and I think this is a really interesting and important discussion to have. Thanks for writing it up! I don't think I would put the chances as high as 10% though.
I don't find the Turing test evidence as convincing as you present it here. The paper you cited released their test online for people to try. I played it quite a lot, and I was always able to distinguish the human from the AI (they don't tell you which AI you are paired with, but presumably some of those were with GPT-4.5).
I think a kind of Turing test could be a good test for consciousness, but only if it is long, informed, and adversarial (e.g. as defined here: https://www.metaculus.com/questions/11861/when-will-ai-pass-a-difficult-turing-test/ ). This version of the test has not been passed (although as someone pointed out to me on the forum before, this was not Turing's original definition).
On the other hand, I don't find your strongest argument against LLM consciousness to be as convincing either. I agree that if each token you read is generated by a single forward pass through a network of fixed weights, then it seems hard to imagine how there could be any 'inner life' behind the words. There is no introspection. But this is not how the new generation of reasoning models work. They create a 'chain of thought' before producing an answer, which looks a lot like introspection if you read it!
I can imagine how something like an LLM reasoning model could become conscious. It's interesting that they didn't use any reasoning models in that Turing test paper!
Fair enough, I did not actually read the paper! I have talked to LLMs about consciousness and to me they seem pretty good at talking about it.
The chain of thought is still generated via feed-forward next token prediction, right?
A commenter on my blog suggested that LLMs could still be doing enough internally that they are conscious even while generating only one token at a time, which sounds reasonable to me.
Yes, it is.. But it still feels different to me.
If it's possible to create consciousness on a computer at all, then at some level it will have to consist of mechanical operations which can't by themselves be conscious. This is because you could ultimately understand what it is doing as a set of simple instructions being carried out on a processor. So although I can't see how a single forward pass through a neural network could involve consciousness, I don't think a larger system being built out of these operations should rule out that larger system being conscious.
In a non-reasoning model, each token in the output is generated spontaneously, which means I can't see how there could be any conscious deliberation behind it. For example, it can't decide to spend longer thinking about a hard problem than an easier one, in the way a human might. I find it hard to get my head around a conscioussness that can't do that.
In a reasoning model, none of this applies.
(Although it's true that the distinction probably isn't quite as clear cut as I'm making out. A non-reasoning model could still decide to use its output to write out "chain of thought" style reasoning, for example.)
Yes, it could well be that an LLM isn't conscious on a single pass, but it becomes conscious across multiple passes.
This is analogous to the Chinese room argument, but I don't take the Chinese room argument as a reductio ad absurdum—unless you're a substance dualist or a panpsychist, I think you have to believe that a conscious being is made up of parts that are not themselves conscious.
(And even under panpsychism I think you still have to believe that the composed being is conscious in a way that the individual parts aren't? Not sure.)