tom4everitt

Research Scientist at DeepMind

The point here isn't that the content recommender is optimised to use covert means in particular, but that it is **not** optimised to avoid them. Therefore it may well end up using them, as they might be the easiest path to reward.

Re Markov blankets, won't any kind of information penetrate a human's Markov blanket, as any information received will alter the human's brain state?

Thanks, that's a nice compilation, I added the link to the post. Let me check with some of the others in the group, who might be interested in chatting further about this

Sure, I think we're saying the same thing: causality is frame dependent, and the variables define the frame (in your example, you and the sensor have different measurement procedures for detecting the purple cube, so you don't actually talk about the same random variable).

How big a problem is it? In practice it seems usually fine, if we're careful to test our sensor / double check we're using language in the same way. In theory, scaled up to super intelligence, it's not impossible it would be a problem.

But I would also like to emphasize that the problem you're pointing to isn't restricted to causality, it goes for all kinds of linguistic reference. So to the extent we like to talk about AI systems doing things at all, causality is no worse than natural language, or other formal languages.

I think people sometimes hold it to a higher bar than natural language, because it feels like a formal language could somehow naturally intersect with a programmed AI. But of course causality doesn't solve the reference problem in general. Partly for this reason, we're mostly using causality as a descriptive language to talk clearly and precisely (relative to human terms) about AI systems and their properties.

The way I think about this, is that the variables constitute a reference frame. They define particular well-defined measurements that can be done, which all observers would agree about. In order to talk about interventions, there must also be a well-defined "set" operation associated with each variable, so that the effect of interventions is well-defined.

Once we have the variables, and a "set" and "get" operation for each (i.e. intervene and observe operations), then causality is an objective property of the universe. Regardless who does the experiment (i.e. sets a few variables) and does the measurement (i.e. observes some variables), the outcome will follow the same distribution.

So in short, I don't think we need to talk about an agent observer beyond what we already say about the variables.

nice, yes, I think logical induction might be a way to formalise this, though others would know much more about it

I had intended to be using the program's output as a time series of bits, where we are considering the bits to be "sampling" from A and B. Let's say it's a program that outputs the binary digits of pi. I have no idea what the bits are (after the first few) but there is a sense in which P(A) = 0.5 for either A = 0 or A = 1, and at any timestep. The same is true for P(B). So P(A)P(B) = 0.25. But clearly P(A = 0, B = 0) = 0.5, and P(A = 0, B = 1) = 0, et cetera. So in that case, they're not probabilistically independent, and therefore there is a correlation not due to a causal influence.

Just to chip in on this: in the case you're describing, the numbers are not **statistically** correlated, because they are not random in the statistics sense. They are only random given **logical** uncertainty.

When considering logical "random" variables, there might well be a common logical "cause" behind any correlation. But I don't think we know how to properly formalise or talk about that yet. Perhaps one day we can articulate a logical version of Reichenbach's principle :)

Thanks for the suggestion. We made an effort to be brief, but perhaps we went too far. In our paper Reasoning about causality in games, we have a longer discussion about probabilistic, causal, and structural models (in Section 2), and Pearl's book A Primer also offers a more comprehensive introduction.

I agree with you that causality offers a way to make out-of-distribution predictions (in post number 6, we plan to go much deeper into this). In fact, a causal Bayesian network is equivalent to an exponentially large set of probability distributions, where there is one joint distribution $P_{\do(X=x)}$ for any possible combinations of interventions $X=x$.

We'll probably at least add some pointers to further reading, per your suggestion. (ETA: also added a short paragraph near the end of the Intervention section.)

Preferences and goals are obviously very important. But I'm not sure they are inherently causal, which is why they don't have their own bullet point on that list. We'll go into more detail in subsequent posts

I see, thanks for the careful explanation.

I think the kind of manipulation you have in mind is bypassing the human's rational deliberation, which is an important one. This is roughly what I have in mind when I say "covert influence".

So in response to your first comment: given that the above can be properly defined, there should also be a distinction between using and not using covert influence?

Whether manipulation can be defined as penetration of a Markov blanket, it's possible. I think my main question is how much it adds to the analysis, to characterise it in terms of a Markov blanket. Because it's non-trivial to define the membrane variable, in a way that information that "covertly" passes through my eyes and ears bypasses the membrane, while other information is mediated by the membrane.

The SEP article does a pretty good job at spelling out the many different forms manipulation can take https://plato.stanford.edu/entries/ethics-manipulation/