9 ms·
Epidemiologist in training here... There are quite a few comments in this thread already jumping on the 'correlation != causation' train. While that is true, I
by i_love_limes 4y ago
Epidemiologist in training here... There are quite a few comments in this thread already jumping on the 'correlation != causation' train. While that is true, I'd like to clarify a couple things:
1. The journal article didn't suggest it was causal. But such a correlation with such a large population warrants publication and further research into causation.
2. literally the first thing that any epidemiologist would consider is potential confounders. There is a big list of covariates they included into their model here: https://content.iospress.com/articles/journal-of-alzheimers-disease/jad220361#jad--1-jad220361-t002 https://content.iospress.com/articles/journal-of-alzheimers-...
There are quite a few things that can be done to alleviate potential false correlations: DAGs, prior literature, removing confounders, and including covariates are all things at disposal.
3. Such a large sample size + previously reported findings + an inclusion of enough covariates still doesn't == causation, BUT it's important to publish and shout about so we can then look into the potential biological underpinnings that may cause this. Which by the way, those experiments may still use data science techniques.
4. If you are actually interested, there is a whole topic of this called 'causal inference' with one famous criteria list called the 'Bradford Hill Criteria': https://en.wikipedia.org/wiki/Bradford_Hill_criteria https://en.wikipedia.org/wiki/Bradford_Hill_criteria. This list is often argued about.
5. If all of this information was new to you, please stop spouting 'correlation != causation'. You probably don't know as much as you think
- itsoktocry 4y ago>There are quite a few comments in this thread already jumping on the 'correlation != causation' train. Complaining about correlation not being causation is the perfect theme for the midwit meme. It's one of my pet peeves.
- deleted 4y ago[deleted]
- planarhobbit 4y agoI’d say they should show evidence that they know what they’re talking about, but then I’d be accused of credentialism.
- LargeWu 4y agoBeing able to demonstrate technical understanding of a problem isn't credentialism. Conversely, having an undergraduate degree in X isn't evidence of expertise.
- mortenjorck 4y agoThe brainlet and sage text is “maybe x causes y.”
- BrandoElFollito 4y agoI do not remember where I read it (probably xkcd) but it was that correlation is not casuation, though the numbers are doing big winks to you (or something like that) As a physicist who had to endure helping biologists with statistics and cooling down their enthusiasm: it make sense to have a deeper thought about the experiment. As parent wrote, there may be various reasons for the correlations, sometimes you have random stuff, sometimes indirect stuff and in others extraordinary stuff. Many discoveries (especially older ones) fall into the last category.
- Symmetry 4y agoI like the phrasing, "Correlation correlates with causation because causation causes correlations".
- thaumasiotes 4y agoCausation frequently removes correlations that would otherwise exist.
- Symmetry 4y agoI don't think that's right? In theory you could have A and B that were naturally correlated and add a causal relationship between the two that exactly canceled that correlation but that would be infinity unlikely to happen by chance. In practice the only way that A and B can be correlated is that either A causes B, B causes A, or some C causes both A and B. Interestingly if both A and B cause C the C and A as well as C and B will be correlated but A and B won't be, allowing you to work out causation from a strictly correlational graph.
- gweinberg 4y agoIt's not by chance. If you have a heater controlled by a thermostat, it destroys the correlation that would otherwise exist between outside temperature and inside temperature. That particular example sounds silly because it is so obvious. But in economics you can find examples where you would be seeing a relationship, but it is masked by an active response to the cause, but it's not so obvious this is happening.
- blagie 4y agoThe scientists said it was causation. "We found that flu vaccination in older adults reduces the risk of developing Alzheimer’s disease for several years. The strength of this protective effect increased with the number of years that a person received an annual flu vaccine – in other words, the rate of developing Alzheimer’s was lowest among those who consistently received the flu vaccine every year" Yes, that's in an interview for the article. That's the reason (1) the general public misunderstands (2) people scream about it. Scientists get points for "high-impact research," and there is strong incentive to be dishonest. (As a footnote, personally, I do believe it is causation; I believe that as with COVID and EB, we've dramatically underestimated the long-term impact of many viral infections. But that's just a personal belief.)
- itsoktocry 4y ago>The scientists said it was causation. Interesting. I don't read that as claiming causation, I read that as describing the correlation. You're right though, it's confusing messaging, regardless.
- deleted 4y ago[deleted]
- threatofrain 4y agoI've always read "protective effect" to be making a predictive statement and not a causal one.
- Izkata 4y ago"Reduce" is also an action verb that means causation.
- threatofrain 4y agoThe presence of protective effects reduces the expectation of future observations of something, and merely describes temporal correlation. I so far just see standard language used in literature.
- amacneil 4y agoIf they only intend to claim correlation, avoiding the word "linked" in the announcement would probably help with general public interpretation. I feel like in English, "linked" usually implies some sort of potential causation, not just a general relationship. For example: "boyfriend linked to murder case".
- pcl 4y agoThis reminds me of the intentionally-ambiguous "officer-involved shooting" turn of phrase. https://www.mcsweeneys.net/articles/an-interactive-guide-to-ambiguous-grammar https://www.mcsweeneys.net/articles/an-interactive-guide-to-... https://www.cjr.org/analysis/officer-involved-shooting.php https://www.cjr.org/analysis/officer-involved-shooting.php
- sudosysgen 4y agoCorrelations do imply a link, though. They don't imply causation, but in the absence of selection bias and with enough of a sample size, it is almost certain there is a link somewhere.
- hypertele-Xii 4y agoThe word for when there is no link is, in turn, 'coincidence'. Causation, correlation, coincidence. And then there's quantum entanglement.
- toolz 4y agoWell let's test this theory out then. Would you say I was being ridiculous if I told you that the number of people who drown in a year is linked to how many movies nicolas cage appears in? If so, then you might not actually believe linked is simply a synonym for correlation. I know I certainly would think that was a ridiculous way to phrase it.
- MrsPeaches 4y ago> the number of people who drown in a year is linked to how many movies nicolas cage appears in For those who don't know the reference: http://www.tylervigen.com/spurious-correlations http://www.tylervigen.com/spurious-correlations
- georgia_peach 4y agoThank you for posting this. I doubt people can make it to adulthood--or even manage speaking in complete sentences--without having some rudimentary appreciation for "correlation != causation", yet it is so frequently posted--both here & the r-place. And its vileness is far beyond midwittery. It is a lazy & incredibly weasely way to stifle unwelcome lines of inquiry: by pre-emptively accusing anyone who would continue along those lines as a mental defective. That being said, modern research is mostly a profit/status driven false-positive factory. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1182327/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1182327/
- aaron695 4y ago