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Correlation is usually not causation. But why not?

gwern.net

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Re: Correlation is usually not causation. But why not?

#51

The difference between correlation and causation is merely conventional. Does the striking of a match cause it to ignite? There is no way to prove that it does, only the correlation between the striking and the ignition makes us say they're causal. Correlation is the only way to determine what's causal and what's not. On the other hand, if you want to look at it philosophically, then the only sensible definition of "…

I agree with others. Your comment is nonsense. But the match question is more complicated than it looks.

Striking a match causes ignition because other humans have already made a long list of correlations and found them reliable enough to build a thing called a 'match'.

This is one of the differences between science and technology. Technology is practical causality. You know enough about phenomena to be reasonably confident that you can assemble them into configurations that do useful things in a reliable way.

Science is about not being sure if correlations exist until you check to find out. Science is also about building abstract models that can reliably predict unexpected correlations.

I'm not sure there's more to the idea of causation than reliable correlation backed up by elegant and efficient abstraction with predictive power. (There probably is, but it's not something I've looked into enough.)

Quantum theory has a habit of pushing this in unexpected directions. It seems to be about manipulating probabilities rather than objects. The idea that you can causally manipulate a probability distribution is a deeply weird one if you stop to wonder what exactly is being manipulated in physical terms, and how.

Re: Correlation is usually not causation. But why not?

#53
The problem is that causation is an oxymoron.

The measurement problem is the same as the problem of induction.

Max Planck understood this, read his quotes on matter.

No amount of correlation increases the probability of one event followed by another. Therefore, all scientific analysis is unverifiable. Knowledge of the world is completely unjustified. Not to mention our immense presumption of consistency in world phenomena when we really have no basis for asserting uniformity of nature. Read Hume on causality.

"Belief in the Causal Nexus is superstition" - Wittgenstein

If knowledge requires certainty, and our method of determining certainty is an infinite regress of reduction, it is like a recursive function which never returns a value.

Logic is inherently a comparison operator, and if logic is the only mechanism available to us, we are trapped in a purely relational analysis and it is impossible for the mind to conceive of certainty beyond a non-reasonable emotional preordained state of knowing. A feeling so powerful it is personally indubitable.

The premise of a singularity is invalid since it is inconceivable and the idea that causation is at any time inferred via comparison is fundamentally incomprehensible. If the premise is unclear then the argument is invalid.

If I say that an airplane functions on fairy dust and you make an argument about propulsion and lift, and you claim that my assertion is wrong because I have not properly performed a rational reduction and that a detail I do not understand could invalidate my entire theory, well guess what neither of us is technically correct to any degree since the test for invalidity applies equally to both of our assumptions. The concept of proof is also an oxymoron.

Hence, the very concept of phenomenal causation is an oxymoron. The notion of knowledge about the world is a disguise for a coping mechanism based on hope and desire.

Re: Correlation is usually not causation. But why not?

#54
post #53

The problem is that causation is an oxymoron. The measurement problem is the same as the problem of induction. Max Planck understood this, read his quotes on matter. No amount of correlation increases the probability of one event followed by another. Therefore, all scientific analysis is unverifiable. Knowledge of the world is completely unjustified. Not to mention our immense presumption of consistency in world phen…

I couldn't edit, so I'll reply, but this mind bending quote really sums up the limitations of logic and observation.

"Language disguises the thought; so that from the external form of the clothes one cannot infer the form of the thought they clothe, because the external form of the clothes is constructed with quite another object than to let the form of the body be recognized." - Wittgenstein

Re: Correlation is usually not causation. But why not?

#55
post #53

The problem is that causation is an oxymoron. The measurement problem is the same as the problem of induction. Max Planck understood this, read his quotes on matter. No amount of correlation increases the probability of one event followed by another. Therefore, all scientific analysis is unverifiable. Knowledge of the world is completely unjustified. Not to mention our immense presumption of consistency in world phen…

I do agree with you that science doesn't show causation, but I think your interpretation of science is incorrect:

> Therefore, all scientific analysis is unverifiable.

I disagree. It's verified by experiment. (Here I'm using "verify" to mean that contradictions have not (yet) been found by experimental observation).

> Knowledge of the world is completely unjustified.

I disagree. Again, it's justified by experiment. If that's not enough for you, too bad, because that's all we have.

> Our immense presumption of consistency in world phenomena when we really have no basis for asserting uniformity of nature.

I disagree. This is only asserted insofar as it's 1) useful, and 2) justified by observation.

I don't think you understand the significance of scientific results. They don't say "at a fundamental, irreducible level, this is how operates." Rather, they're saying something more along the lines of "as far as we can tell, this is a description of how operates, but it's entirely possible that we're wrong. However, we don't have any data that shows that we're wrong (yet), and because this description is useful for understanding , we're going to use it."

We don't need to know how a system works at a fundamental level, if understanding it at a less-detailed level is useful. I do agree with you that we can't determine "actual causality", but we don't need to, if we can instead find a bunch of really good correlations. The problem is that people find lots of crappy correlations, and/or can't tell the difference between good and crappy correlations.

Re: Correlation is usually not causation. But why not?

#56
post #53

The problem is that causation is an oxymoron. The measurement problem is the same as the problem of induction. Max Planck understood this, read his quotes on matter. No amount of correlation increases the probability of one event followed by another. Therefore, all scientific analysis is unverifiable. Knowledge of the world is completely unjustified. Not to mention our immense presumption of consistency in world phen…

I do agree with you that science doesn't show causation, but I think your interpretation of science is incorrect: > Therefore, all scientific analysis is unverifiable. I disagree. It's verified by experiment. (Here I'm using "verify" to mean that contradictions have not (yet) been found by experimental observation). > Knowledge of the world is completely unjustified. I disagree. Again, it's justified by experiment. I…

Go further: reproducible experiment can tease out details to many decimal places of likelihood. Something can be known so thoroughly that we can make statements like "this is certain to behave as predicted millions or billions of times more often that not", which is pretty close to certain knowledge.

Re: Correlation is usually not causation. But why not?

#57
post #53

The problem is that causation is an oxymoron. The measurement problem is the same as the problem of induction. Max Planck understood this, read his quotes on matter. No amount of correlation increases the probability of one event followed by another. Therefore, all scientific analysis is unverifiable. Knowledge of the world is completely unjustified. Not to mention our immense presumption of consistency in world phen…

I do agree with you that science doesn't show causation, but I think your interpretation of science is incorrect: > Therefore, all scientific analysis is unverifiable. I disagree. It's verified by experiment. (Here I'm using "verify" to mean that contradictions have not (yet) been found by experimental observation). > Knowledge of the world is completely unjustified. I disagree. Again, it's justified by experiment. I…

Philosophically speaking you can never verify anything through experimentation: in a controlled experiment you will use instruments and tools you need to trust (how do you know the microscope isn't lying?) and if you go through the process of trying to see if anything is confirmed, for a long enough time you will end up with the axioms of any scientific field, which are never verified (just assumed true).

You can prove negatives though, so thats something :).

Re: Correlation is usually not causation. But why not?

#58

Earlier quoted context omitted.

I do agree with you that science doesn't show causation, but I think your interpretation of science is incorrect: > Therefore, all scientific analysis is unverifiable. I disagree. It's verified by experiment. (Here I'm using "verify" to mean that contradictions have not (yet) been found by experimental observation). > Knowledge of the world is completely unjustified. I disagree. Again, it's justified by experiment. I…

Philosophically speaking you can never verify anything through experimentation: in a controlled experiment you will use instruments and tools you need to trust (how do you know the microscope isn't lying?) and if you go through the process of trying to see if anything is confirmed, for a long enough time you will end up with the axioms of any scientific field, which are never verified (just assumed true). You can pro…

> Philosophically speaking you can never verify anything through experimentation

This depends on what you mean by "verify". You seem to mean "prove that something is absolutely true".

That is not what I meant. I should have clarified that I meant something along the lines of "we've collected a bunch of data that don't contradict ".

I've edited my meaning into the post because I don't want my stupid equivocation to distract from more significant issues.

Re: Correlation is usually not causation. But why not?

#59
post #53

The problem is that causation is an oxymoron. The measurement problem is the same as the problem of induction. Max Planck understood this, read his quotes on matter. No amount of correlation increases the probability of one event followed by another. Therefore, all scientific analysis is unverifiable. Knowledge of the world is completely unjustified. Not to mention our immense presumption of consistency in world phen…

> If I say that an airplane functions on fairy dust and you make an argument about propulsion and lift, and you claim that my assertion is wrong because ...

The only reason "science" would claim that your assertion is wrong is if your explanation doesn't agree with reality.

However, if you collect a bunch of data that you say supports your theory, but your experimental technique or data analysis is not good, then it's perfectly reasonable to point out the problems and say that your result is not supported by your procedure. This is not the same as saying that your assertion is wrong.

Another important concept that you're missing is usefulness: your assertion is unlikely to be useful (this is totally different from whether it's correct). Let's say you want to ensure that planes don't fall out of the air: how would you take advantage of your assertion to do this? (My proxy for usefulness is falsifiability -- un-falsifiable theories often are useless)

Re: Correlation is usually not causation. But why not?

#60
post #50

All I know about causation and correlation I learnt hunting bugs in large legacy software systems. In that environment I got the impression that correlation almost never equalled causation, but that's only because the hardest bugs, the ones I remembered, were hard because the obvious correlations did not help identify the root cause. A similar argument might be made for scientific studies: most of the easy causes tha…

I think this low-hanging-fruit idea is generally true for all of science: after centuries of science as a profession, pretty much all the easy stuff has already been done. It's actually an argument for more cojones in science-- being willing to do bold stuff and explore "crazy" hypotheses. If all the easy stuff is done already, then picking methodically and timidly among the dregs is unlikely to ever yield anything.

An alternative viewpoint: everything's easy after it's been done, but it's hard up until then.

> after centuries of science as a profession, pretty much all the easy stuff has already been done.

But with the benefit of all that has already been done, shouldn't we be able to do things now that were previously impossible? In other words, "easy in 2014" != "easy in 1200".

> It's actually an argument for more cojones in science-- being willing to do bold stuff and explore "crazy" hypotheses.

Maybe doing whatever's easy is the most efficient (by time, money) way to make progress?

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