Personal Evidence - Superstitions as Rational Beliefs

Forget the whole philosophy and meta side of this. If the events you describe really happened, then there is a sneaky, insane and probably dangerous human around. If this were a B-movie horror, you would search the house alone and unarmed, find a concealed door in the "alien geometry" basement room, open it and be ambushed. Tread carefully. If a key goes missing and then reappears, it has been copied. If a previous occupant's possessions turn up mysteriously, then the lurker has been around for awhile. Hidden cameras are a useful tool. In any case, it is dangerous to tip him off that you know, unless you are ready to act (as in, bring in police, conduct a thorough search with special equipment, and change all locks) immediately.

You should assign a much higher probability to your being a victim of gaslighting than to your having experienced supernatural events.

It sounds like an old house, based on the structural abnormalities. Is it possible that there is a gas leak? One prime candidate for the "haunted house" phenomenon is hallucinations brought on by exposure to carbon monoxide.

I think it worth pointing out that it's very difficult to remove selective perception and confirmation bias here. For example, if I experienced the "dropped key" scenario you described, I would simply assume that the key had slid or been kicked out of the room, and then someone else had later found it and set it down somewhere off the ground. However, if I believed that I lived in a Haunted House, the first hypothesis that would spring to mind would be that the key's teleportation was part of the haunting. So when you say such incidents have not occurred since you lived in that house, I believe that you think that, but it's likely that you just don't view incidents outside the house as existing in the same magisterium, in some sense.

Additionally, I happened to be pondering today why people seem to take Aumann's Agreement Theorem so literally around here. It is a mathematical idealization. We're not talking about the mathematics of particle physics, we're talking about the cognition and interactions of humans, who only barely do reasoning in the first place and barely succeed in communicating even the simplest concepts without signal loss.

(Commenters: talking about the 'supernatural' in terms of metaphysics is metaphysically interesting but phenomenologically speaking it just clouds the issue unnecessarily. The way most people actually use the concept is just 'weird things happening that would require human or transhuman agency, in situations where there's no good reason to suspect human agency'. Talking about reductionism &c. is missing the point---it doesn't matter whether the agency comes from an engineered superintelligence or an "ontologically fundamental" god, what matters is there's non-human agency around. Note that all reports of supernatural phenomena can be explained "naturally" by superintelligences, simulators, highly advanced aliens, &c., all of which seem not-unlikely in a big universe. The improbability stems from the necessity of their having seemingly bizarre motivations; the mechanisms themselves, however, aren't fantastically improbable.)

If this were a mystery story, the prime suspects would be the people who helped you search for the key :)

If you have a spare computer and some spare time, you could surreptitiously set up a few sneaky cameras. Just don't tell those people. If you think this is supernatural with, say, p>10%, this sounds like a fun thing to investigate. Well, fun now that you're out of a house that was for one reason or another correlated with you having night terrors.

I used to experience periodic attacks of sleep paralysis. The first few times it happened to me I had no idea what was happening; I had vivid auditory hallucinations as well as the strong sensation that someone else was in my bedroom. Occasionally I would feel an enormous pressure on my chest.

I later learned that sleep paralysis may have inspired a lot of folklore, e.g. incubi. If a thousand years ago I reported these symptoms and someone told me "a demon is sitting on you," I would have been hard-pressed to come up with a better hypothesis.

I second Manfred. Set up cameras. Don't worship your (partial) ignorance, fix it!

Woah woah woah, back up here. Why would you want to move out of this goldmine? Lets assume that you're correct and it's a real haunted house and not schizophrenia/people-in-the-walls/mental-abuse-by-your-sister.

You were in a house where objects were repeatedly, purposefully moved without human intervention. Just take a look at the incident where key lime juice got into the oven: either the haunted house teleported it from your fridge to your oven, or the haunting house generated action-without-reaction and floated it from the fridge to the oven.

[*] In case A, you've just broken the Theory of Relativity and can help humans colonize the stars with instant teleportation. Please collect your 100 nobel prizes, 100 billion dollars, and knowledge that you've protected all of humanity from any possible existential risk.

[*] In case B, you've just broken the Laws of Thermodynamics and can help humanity defeat entropy itself. Please collect your 200 nobel prizes, 500 billion dollars, and the knowledge that you've literally saved all of existence for all time.

You've gotten the most valuable thing that has ever existed on this planet living in your house, and you want to give up ownership.

Either that or your sister is crazy and hates key lime juice. 50/50 equally likely.

The evidence I have personally seen suggests haunted houses are, in fact, real, without given any particular credence to any particular explanation of what the haunting is.

So, it seems like there's a strong and weak interpretation of this sentence.

The weak interpretation (that I endorse) is "reported physical evidence is often physical"- crop circles aren't photoshopped, they're actually there in the fields. Throwing out the evidence with the interpretation is rarely wise. Talking with someone who believes in alien abduction reports, I get the sense that there are a number of them where it's reasonable to believe that weird things were really noticed (like someone's lawn having an abnormal amount of radiation, or so on). Under this interpretation, you probably ought to move out of the house / set up hidden cameras / etc.; if any of these are the result of hallucinations or the actions of others or the unremembered actions of yourself, then setting up systems to counteract that is a good idea.

In this interpretation, a "superstition" is more of a "unarticulated causal model." It isn't that "ghosts live in the house, and move objects around," it's "something unknown about this house is bad, and I should avoid it." (That particular model doesn't even articulate why it's bad- it accepts both teleporting keys and your memory being faulty.)

The strong interpretation (that I don't endorse) is "physical evidence is anywhere near close enough to overcome a sensible prior against the supernatural." If there really are crop circles in your fields, it's still many, many times more likely that you're doing it while sleepwalking, or other humans are doing it to you, or some other mundane explanation, than that aliens are doing it to you. I will note that it is often useful to take the outside view on your own evidence, especially if you have or are developing a mental disorder. "If someone told me that there were invisible ants crawling all over them, how likely is it that they're hallucinating? Very likely, and from that I should expect that the invisible ants crawling all over me aren't real." I wrote a post about this a while back that may be interesting.

Aumann was, in short, wrong, because Aumann Updating is based on the belief that two individuals -can- share evidence. Evidence is incompletely transferable.

I don't care to respond to the rest of your post, but I feel I should point out that saying a theorem is wrong because the hypotheses are not true is bad logic.

p(X|M)=p(M|X)*P(X)/P(M)
Assuming X guarantees M and O, we get:
p(X|M)=P(X)/P(M)
p(X|O)=P(X)/P(O)
where p(M) = p(O) / Z
Which means
p(X|M) = p(X|O) * Z

Which is to say, M is stronger evidence than O for Z:
p(X|M, M1) = p(M|X)*P(X|M1)/p(M|M1)
p(X|O, O1) = p(O|X)*P(X|O1)/p(O|O1)

Using the above assumption that X guarantees M and O:
p(X|M, M1) = p(X|M1)/P(M|M1)
p(X|O, O1) = p(X|O1)/P(O|O1)

Substituting, again where P(O1) = p(M1) * Z, and where p(M1|M) and p(O1|O) are both 1:

p(X|M, M1) = p(X|M1)/p(M|M1)
p(X|O, O1) = (P(X)/Z*P(M1)) / (Z*P(M) / Z*P(M1))
= p(X)/(Z*P(M))

p(X|M, M1) = p(M|X)\*P(X|M1)/p(M|M1)

Have you checked the house for mold? The night terrors seem pretty well-explained by mycotoxins and the odds of the other weirdness also go up if something is screwing with your biochemistry.

Since no one mentioned this famous excerpt from Feynman's bio yet:

He was at work in the computing room when the call came from Albuquerque that Arline was dying. He had arranged to borrow Klaus Fuchs’s car. When he reached her room she was still. Her eyes barely followed him as he moved. He sat with her for hours, aware of the minutes passing on her clock, aware of something momentous that he could not quite feel. He heard her breaths stop and start, heard her efforts to swallow, and tried to think about the science of it, the individual cells starved of air, the heart unable to pump.

Finally he heard a last small breath, and a nurse came and said that Arline was dead. He leaned over to kiss her and made a mental note of the surprising scent of her hair, surprising because it was the same as always.

The nurse recorded the time of death, 9:21 P.M. He discovered, oddly, that the clock had halted at that moment—just the sort of mystical phenomenon that appealed to unscientific people.

Then an explanation occurred to him. He knew the clock was fragile, because he had repaired it several times, and he decided that the nurse must have stopped it by picking it up to check the time in the dim light.

Gleick, James (2011-02-22). Genius: The Life and Science of Richard Feynman (Kindle Locations 3604-3612).

Okay, I'll bite the lottery bullet. If I happen to win the lottery, then this does not make it more likely that something unusual happened (e.g. the lottery being rigged). The hypothesis that I naturally won the lottery is unlikely, true; but the hypothesis that the lottery was rigged so that I would win is equally unlikely for the exact same reasons: why was it rigged for me to win, and not someone else?

Similarly, in the haunted house situation, you should in fact consider it unlikely that these events would happen to you. However, this penalty should apply equally to just about any explanation: it's equally unlikely that psychopaths would choose you, specifically, to play tricks on, as it is that you, specifically, would happen to find yourself in a haunted house.

The only way to break symmetry is if you have reason to believe that some kind of rare event is more likely to happen to you. Is there something about you that makes you more likely to find yourself in a haunted house? (e.g. are you a ditzy blonde girl between the ages of 16 and 19.5?) Then you should update on that. Similarly, if you're related to someone running a lottery, and you find yourself winning it, you should suspect that foul play was involved.

Note that all these explanations carry over: if the lottery winner is related to the lottery organizer, you should suspect foul play whether or not the lottery winner is you.

You might argue that supposing you live in a simulation breaks this: specifically, if we consider simulations of the "everyone you don't know is fake" flavor. In that case, the hypothesis "the simulation is rigged so one of the people being simulated in detail wins" means you have maybe a 1:70 chance of winning, compared to a much smaller chance if the world is big.

But here the improbability is just redirected to a higher level: what are the odds that someone would simulate you, specifically? Once we factor this in, the simulation hypothesis is back to "odds that an arbitrary person finds themselves in a lottery-based simulation". Calculating these odds is beyond the scope of this comment.

This is a textbook example of getting carried away with irrational fascination, and letting one's beliefs drift along lines defined by no more than a disorienting attempt to jam defunct terminology into a new situation. It's reminiscent of when notable academics profess their 'belief in God' by reference to plausibly scientifically defensible positions concerning possible alien intelligences, potential future singularity states, etc. That's not what they meant by "God"!

Why call it "superstition"? Why refer to this as an instance of you updating on anything? You now believe in haunted houses? Really? Tell me, why did you write this post as you did? What would this post have looked like if you did nothing but describe the events that you witnessed? For one, it probably wouldn't have been nearly as fun to write. Nor would it have seemed as on-topic for this forum as it currently does.

You claim you don't believe in supernatural events. You say you believe the house is "haunted", but as no more than a description of these seemingly bizarre occurrences that have yet to be explained. But if you take this seriously, you should be able to rewrite this whole post as just that--a mere description of the events. If by "haunted", you only mean what happened, then there's no reason why you couldn't just rewrite it without that word. If all I mean by "TV" is "television", then I should be able to replace all instances of the first word with the second, and retain my meaning completely.

But then where's the update? What did you change your mind about? Where's the insight? All that's left is a catalog of strange things that happened in your old house. All the interesting philosophy vanishes, and the responses devolve into nothing more engaging than suggestions about what may be going on, or action that may be taken. Gaslighting, EMFs, sleepwalking, a gas leak, etc. Perhaps you should set up some cameras, or get the place inspected. Or maybe you should just get the hell out of there and forget about the whole thing.

Interestingly, my father, a moderately respected scientist, has cited similar reasoning to me when discussing why he believes in supernatural phenomena. He believes he has encountered overwhelmingly convincing evidence, but says he understands that I shouldn't necessarily believe him. This is... a pleasant way to deal with disagreement, if not faultless reasoning.

After reading your thread with gwern, I think you and he are probably wrong about this reasoning in general, and you are probably wrong in your case specifically.

I think it should be possible to encounter supernatural phenomena in such a way that it is extremely convincing to you and not to anyone else. If you were a highly rational agent who encountered real supernatural phenomena, and told (even perfectly rational) people about it, their first reaction would be not to believe you. And this likely makes sense on their part unless you're able to produce extremely good evidence that (you are highly rational AND you are very unlikely to be lying), OR you have reproducible evidence of a particular phenomenon that you can show them.

But you should be able to produce such evidence... if it's not convincing to them, why is it convincing to you?

I would rather believe that two Yankee professors would lie than believe that stones fall from heaven..

"A stone cannot fall from the sky - there ARE no stones in the sky." -- Lavoisier (quote found at the link above)

When you hear something really weird from a number of independent sources, what can you conclude?

This should have been two posts. First, "My house is spooking me, what's up with that? Spooky things, amirite?". Second, "There's some distinct information content between experiencing an event and being told about someone else experiencing that event. Therefore AAT doesn't work, amirite?"

To the second point, I haven't read any write-ups of AAT. Does it say you have to speak messages that have the same evidential impact to others as your accumulated experience does to you? That sounds like a pretty terrible theorem. I thought there was some wiggle room where each agent could regard the other as an imperfect updater, whose words nevertheless had some informativeness about reality, and from that they eventually reach close posteriors given close priors once upon a time. So the end effect is like an evidence swap, but it works even if you can't quite convey the messages you want, so long as your statements are informative about your present belief state at each round of communication and you can each update a bit.

I've had many similar experiences. You might want to search for J. E. Kennedy, capricious psi. And keep in mind it's dangerous to be around human or transhuman intelligences with unknown motivations. Also, yay updating on evidence! Whether the explanation is supernatural or not, the important thing is to keep many hypotheses in mind and not disregard evidence or hypotheses just because they're uncomfortable.

my priors for "weird geographically located feelings and occurrences happen" is a lot higher (as it should be obviously but it's worth stating) than for any of the possible explanations put forward for it. I think EMF like reasons are the most plausible, though. Tricks on memory and feelings seem pretty plausible, eg you didn't actually lose the key except in your pocket, and then dropped it later than you thought you did.

The question of "probability of occuring" is only half the question. For you, the probability that those experiences are in your memory is 1 - they're real. The more interesting probability to explore is the relative likelihood of causes for these memories.

For the three main possibilities (or any others you find more likely than any of them): 1) "supernatural" or non-human action. 2) believable hallucinations (including hallucination of other people's reactions, or environmental causes of hallucinations in multiple people). 3) devious human agency.

what were your prior probabilities of encountering them? Having experienced this strangeness, what are your current probabilities?

My estimate that I will experience something along these lines is something around 0.000001, 0.005, and 0.001 (note that there is some overlap between 2 and 3, and I count "someone inducing hallucinations" as #3 for this). If I did experience things that could be explained by any of them, they would increase massively - they'd sum to something under 1 to account for options I haven't listed. But they'd retain their proportions, so figure 0.0001, 0.5, and 0.1. It would take a lot of evidence to reduce the RELATIVE probability of 1 vs 2 and 3, not just the absolute probability of experiencing weird shit.

So, before your experiences, what were your priors for your main causal hypotheses? and what are your estimates now?

For myself as a reader of the post, I must admit that I add a sub-possibility of #3: the poster is misrepresenting something, intentionally or un-. And that my prior (for experiencing reports from strangers of strange happenings) gives this a higher likelihood than the others by more than an order of magnitude.

Sorry for that, but don't let it stop you from examining your own experiences in a rational way, and finding ways to distinguish among possibilities in order to make correct decisions.

The evidence I have personally seen suggests haunted houses are, in fact, real, without given any particular credence to any particular explanation of what the haunting is.

You should clarify what you mean by "haunted houses." You seem to be using the term "haunted houses," to mean "houses where people have experienced spooky things." If that is all you mean by the phrase "haunted houses," then your belief in them is not unusual in any sense. I believe that many people have had spooky-house experiences that they don't know how to explain.

A sensible way to react to this is to assume that "hauntings" have a variety of causes. One haunted person was hallucinating, one person was being pranked by someone, another had someone secretly living in her root cellar, etc. It seems like you are arguing that "haunted houses" exist as a phenomenon with a common cause (as yet unknown, possibly EMFs). That is an unreasonable way to react.

Also, please post a photo of the alien-geometry room, and tell us what you did with the ultrasound photos.

You mention a housemate, apparently your sister. What's more likely: ghosts, hand-wavy stuff about electric fields, or your sister? Well, you know your sister, I know nothing about her.

Whatever the probabilities, the scariest hypothesis is that it's your sister doing all this. Poltergeists, whatever they are, seem to just do random weird annoying stuff. People, on the other hand, have purposes; crazy people can have crazy purposes.

Well, you notice you're confused: good! Now the best way to proceed is to form hypothesis on what could cause the strange phoenomena and test for those. Is there a ghost in the house? Is gaslighting/EMF messing with your head? Is there someone pranking you? There are various ways to falsify all of those... just test and update.

The evidence I have personally seen suggests haunted houses are, in fact, real, without given any particular credence to any particular explanation of what the haunting is. In particular, I own a house in which bizarre crap has happened since I first moved into it. Persistently. I've moved into another house, and have been making repairs in preparation to sell it; most recently, in a room with almost no furniture, in a space with absolutely no furniture, a key was dropped by myself. Four people searched the area for significant periods of time on three different occasions with no luck. I found it on the floor a week or two ago on top of something that wasn't there when it fell. Which is the straw that broke the camel's back in terms of my skepticism.

Other bizarre things that have happened include such things as my waking up to discover my recently-purchased bottle of key lime juice had been placed in the oven, and the oven turned on; the plastic bottle had just started to melt when I made the discovery. Another situation involved my sister, who one morning (while home alone) walked into the living room and discovered on a previously empty floor three sonograms of the previous occupant's baby. (There were -many- other things; I'm choosing for the purposes of this post the most unusual and least prone-to-outside-explanation occurrences. Night terrors, for example, are easily explained.)

Well that ... sure is weird. Are you planning to set up hidden cameras? Cameras seem like they should deal with most of the competing hypotheses here.

I must say, this seems like it should take a human. Whether hiding in the walls or sleepwalking & high on mold. Even if you couldn't rule out ghosts, they don't seem to fit.

I've read that a lot of people who say that they've lived in "haunted houses" have had weird stuff continue to happen to them even after they move - the house itself didn't have much to do with it.

I just have to point out that just because it's anecdotal evidence doesn't mean we shouldn't take it as evidence- albeit with a good amount of salt. Especially from someone who we have evidence (Being on this site in the first place) is at least mildly rational. (And I'm not even going to mention the ghosts thing.)

I recently started carrying a plastic water bottle around with me. I use to carry a metal one, because I was worried about plastic leaching into the water and that being toxic or something. I decided to investigate the risk recently, and came across a Quora post that's reasurred me that if I wash the bottle with soap, then dry it intermittently, it should be alright.

There is a recycling stamp on every plastic bottle that is usually placed at the bottom with a digit inside (image above). This can help you pretty much understand the rules of recycling/reusing bottles. There are basically 7 codes, explanation of each is below. ... Safely Reusing Plastic Number 1

The major concern with the reuse of plastic bottles isn't that the plastic will leach out harmful chemicals, but rather that bacteria will grow in the bottles. According to PlasticsInfo.org, in plastic labeled number 1, PET plastic itself is sanitary, but when warmed it becomes susceptible to bacteria. When washing bottles for reuse, the key is to thoroughly dry the bottle before refilling it with water or another liquid.

PET plastic bottles are designed and sold for one-time use so they are not shaped with a wide opening for easy cleaning. Consumers must take extra care when washing these bottles in hot soapy water, allowing enough time before refilling for the bottle to completely dry.

Was the alien geometry visible from outside the room? Or would the burglar have had to open the door and thus see the expensive materials before deciding to leave it be?