I think it was confusing for me to use “correlation” to refer to a particular source of correlation. I probably should have called it something like “similarity.” But I think the distinction is very real and very important, and crisp enough to be a natural category.
More precisely, I think that:
Alice and Bob are correlated because Alice is similar to Bob (produced by similar process, running similar algorithm, downstream of the same basic truths about the universe...)
is qualitatively and crucially different from:
Alice and Bob are correlated because Alice is more likely to cooperate if Bob cooperates (so Alice is correlated with her model of Bob, which she constructed to be similar to Bob)
I don’t think either one is a subset of the other. I don’t think these are an exhaustive taxonomy of reasons that two people can be correlated, but I think they are the two most important ones.
For example, maybe I partly have kindness genes because my ancestors kept running into people that are kind for roughly the same reasons as you might be kind (e.g. facts about how evolution works and how neural networks work). So in some sense, being kind counts as a prediction about your decision. Or more directly: I have a bunch of cached heuristics about how to interact with other agents, that I’ll draw on when trying to make my decision, which implicitly involves predicting that you’ll be like other agents.
On its own I don’t see why this would lead me to be kind (if I generally deal with kind people, why does that mean I should be kind?) I think you have to fill in the remaining details somehow, e.g.: maybe I dealt with people who are kind if and only if X is true, and so I have learned to be kind when X is true.
In my taxonomy this is a central example of reciprocity—the correlation flows through a pressure for me to make predictions about when you will be kind, and then be kind when I think that you will be kind, rather than from us using similar procedures to make decisions. I don’t think I would call any version of this story “correlation” (the concept I should have called “similarity”).
I think it was confusing for me to use “correlation” to refer to a particular source of correlation. I probably should have called it something like “similarity.” But I think the distinction is very real and very important, and crisp enough to be a natural category.
More precisely, I think that:
is qualitatively and crucially different from:
I don’t think either one is a subset of the other. I don’t think these are an exhaustive taxonomy of reasons that two people can be correlated, but I think they are the two most important ones.
On its own I don’t see why this would lead me to be kind (if I generally deal with kind people, why does that mean I should be kind?) I think you have to fill in the remaining details somehow, e.g.: maybe I dealt with people who are kind if and only if X is true, and so I have learned to be kind when X is true.
In my taxonomy this is a central example of reciprocity—the correlation flows through a pressure for me to make predictions about when you will be kind, and then be kind when I think that you will be kind, rather than from us using similar procedures to make decisions. I don’t think I would call any version of this story “correlation” (the concept I should have called “similarity”).