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Taxi Drivers: The mean age at death is approximately 67.8 years.

General Population: in the same dataset, life expectancy averaged 74 years.

The average age at which patients are typically diagnosed with Alzheimer's disease is 79.

People in these jobs don't live long enough on average to get diagnosed, at the same rate. The same effect will happen in any job that lowers your life expectancy.


It pains me to see such a low-effort contrarian comment at the top: as stated in TFA taxi drivers are below other profession when controlling for age, and there are multiple professions with lower life expectancy that still have significantly higher Alzheimer rate than taxi drivers.


Fella has read the article, has an argument and some stats. What more do you want from a comment? He isn't running a study.

Besides, the point is a good one. There are a lot of professions. If we glance at the underlying study [0] Figure 1 suggests that we'd probably expect to see an outlier or two in that mess just through chance, we're expecting a few p<0.01. Taxi drivers doing unusually well doesn't seem especially impressive in that light, especially since it is one of the professions that seem to die off rather young and we might expect one of those professions to do rather well on Alzheimers.

[0] https://www.bmj.com/content/387/bmj-2024-082194


The comment insinuates that the study did not control for age. The study controlled for age.

It's not terrible to not make a good point, but it's not a good point. The not good points should not be ranked highly.


But after the study controls for age the starkness of the effect more or less disappears (eyeballing Fig 1, the 2nd graph).

It turns out that there is a profession with a lowest risk of getting Alzheimer's (duh, one had to exist) and it looks like a slight outlier (it's the lowest, we'd expect that one to look like a slight outlier). As outliers go it isn't that impressive, it looks like it is part of a fairly boring distribution. We just plotted 400 data points on the graph, the 1/400 chance weird data point is going to look a little weird. We're actually just reading a lot into the fact that the 2nd data point in ambulance drivers which isn't all that convincing.

Not to knock the study, I'm sure it is a great study. Lots of science done. They do good graphs and all that. But the study appears to be telling me that Alzheimer's is random with respect to occupation and ideally don't spend so much time on the road if you want to live to see old age.


> But after the study controls for age the starkness of the effect more or less disappears (eyeballing Fig 1, the 2nd graph).

Adjusting for age, Alzheimers deaths were 1/100 for taxi drivers, and 1/60 for the general public. That's extremely significant. However you feel about the graphs means nothing compared to the actual numbers presented here.

> I'm sure it is a great study. Lots of science done. They do good graphs and all that.

Your choice to be dismissively anti-science helps to explain the bad point you're making.


Comparing 1/100 and 1/60 doesn't mean anything in terms of statistical significance (you would need to know more).

They aren't being anti-science and it's low-quality to suggest they are.


> That's extremely significant.

What makes you think that is significant at all? Anytime you take a lot of small subsets of a large random sample you expect to find outliers that look a lot like this.

That is https://xkcd.com/882/ seems to better fix the data just as well.


Outliers, sure. Exactly like this though? That depends. Since this is a population then assuming a gaussian (which could well be wrong for a variety of reasons I'm just guessing here) what's sigma? If 1/100 is within ~3 sigma then sure. Otherwise no.


It is an outcome from over 400 data points. We're expecting to see events outside a 3 sigma boundary. In fact, 3 sigma is basically the 1:400 boundary. Strictly it is 1 in 370 [0] for anyone who takes Wikipedia at face value.

In the study they seem put the P value of the taxi driver outcome at <0.01 (in Table 2, although I admit I haven't read the thing especially closely). For 400 data points, we expect there to be around 4 values with a P value less than <0.01.

[0] https://en.wikipedia.org/wiki/68%E2%80%9395%E2%80%9399.7_rul...


It needs more statistical analysis than I have the background to do. However all signs look to another variation of the replication crisis, which is more an more my default assumption when I see an observational study.


You're handwaving. The xkcd point only applies if you're within ~3 sigma. This isn't a complicated statistical analysis it's just asking how far out the outlier is versus the standard deviation and size of the dataset.

To be clear I'm not claiming in one direction or the other. I feel that if you're going to attempt to discredit a piece of work it's on you to do such a basic check.

Really the whole point of that xkcd was to viscerally illustrate the practical effect of binary misclassification, or alternatively to make the point that a p of 0.05 isn't necessarily as rigorous as you might expect. Neither of those things directly applies here.


The article doesn't give enough information to answer your question. It isn't on me it is on the reporter's who shouldn't allow a handwave like that to pass without question. There are far to many cases of people hacking statistics in the world to accept that.


It's getting hard to find any study posted without a kneejerk "correlation does not equal causation" take as if that's not something researchers have to control for in order to even conduct the study in the first place, let alone publish


The institutional media departments, journalists, and headline writers add back in the insinuated causation and effect size as a routine matter. That way we can't find fault with the researchers for their clickbait study.


> kneejerk "correlation does not equal causation"

The article (and apparently the researchers too) advances the idea there's a causal link here, even though one is not shown by the research. They go so far as to generally prescribe spatial reasoning training as a way to reduce Alzheimers risk.

You might be tired of hearing "correlation does not equal causation", but it needs to be said here.


On hackernews I really don't think it needs to be said. Call me arrogant/too generous to this community, but I think most of the users here know the phrase and its meaning. Seeing 8000 variants of it doesn't contribute, and since it costs nothing to say "I bet they made a mistake" while elevating your own intellect people default to it far too much.


Read the comment I replied to. It claims the researches must have somehow controlled for correlation (whatever that’s supposed to mean). Which they haven’t. There are a bunch of other comments arguing there’s something beyond correlation shown here. But it hasn’t. The study just demonstrates correlation.

The misunderstanding here is widespread so it worth calling out.

It’s actually kind of funny that people are more sick of the mistake being pointed out over and over than of the mistake being made over and over.


Ok, if we’re going to play this game, what indicates they are making “correlation = causation” errors? What specifically about this study fell for that trap and has not shown something meaningful? You seem very confident they screwed this up, so there must be a reason. And no I’m not digging through your comments to piece together your argument lol I’m sorry but it is ridiculous of you to expect me to comb through your comments and synthesize your point. If your comments were so thorough and proved it then just copy and paste 1 or 2 here that are driving the point home with actual evidence.


> Fella has read the article

Their argument doesn't show that at all though, they make an argument against an age bias when the article explicitly says age is being controlled for.

> Figure 1 suggests that we'd probably expect to see an outlier or two in that mess just through chance, we're expecting a few p<0.01.

That's a valid point, and a much better criticism than the one I'm calling out. That doesn't redeem the original comment though.


A distinction is that Alzheimer's is in an uncommon category of mystery diseases.

If a study found people who swim regularly are are less likely to get heart disease, that wouldn't be very surprising because know a lot about why people get heart disease. Therefore it would be valid to insist on more rigour for accepting (swimming => less heart disease) because the only use of that information is for health advice.

However even weak statistical correlations can be a valid lead for further research into Alzheimer's disease if they suggest where to look. You don't need to prove that signposts are correct in order to use them.


It's worth publication and awareness within people studying Alzheimer.

It's absolutely not worth publication with clickbait title and distorted description to the general public.


> Fella has read the article

Then not closely enough? The study adjusts for age, which is the core of OP’s criticism.


If we read OP's comment closely, it appears to be technically correct. I can imagine someone not upvoting it because it seems to be generic, but there isn't anything wrong or low effort about with it. And I don't see where the stats came from if he hasn't read the article.


"study adjusts for age"

maybe it would help this thread to have someone explain exactly how they control for age, if everyone in the range they want to study, is already dead.

What is the actual process to control for age? This comes up a lot, and the only response is "oh, well, we controlled for that", well exactly how?

Seriously, I'm curious.

//lot of downvotes, not a lot of anybody actually able to explain it.

From Article, the age question does seem sketchy.

"Although proportional mortality analyses do not provide information about the population at risk, with careful selection of controls and risk adjustment for factors that may affect competing risks (eg, age, sex, and social class), these values can still serve as a useful indicator of variations in disease frequency across different occupations.16 17"


Statistically.

You build a model that describes how likely people are to get diagnosed with Alzhimer's as a function of sex: maybe 12 women out of 100 get it, while 8/100 men are diagnosed. You can do the same thing for age: almost nobody is diagnosed before 30, it's very rare before 40, and sadly common (~1 in 10) after 65 years of age. There are all sorts of mathematical tricks to include multiple variables, account for the fact that you can only be diagnosed once, or that data is "censored" (i.e., missing) at some ages because people have already died.

Based on that, you can then ask if the prevalence of Alzheimer's Disease among cab drivers is surprising, given their demographics. For example, if we know that they skew male and younger, we'd expect that number to be a bit lower than a naive estimate of 10%. In fact, we can calculate that number and then see if it's unexpected given the number we actually see. In practice, you'd actually do this by fitting two models: one containing job and one that doesn't, and see which one best describes the data and how, specifically, the job factor affects the outcome.

However, how well these adjustments work depends on the quality of your data and your modelling. Your model could be missing important factors or have the wrong structure: (e.g., you assume risk is directly proportional to age, but it actually increases more rapidly as you get older). Your data could have problems too: maybe women are more likely to go to the doctor (and thus get diagnosed), even if the actual prevalence is the same.


As long as a researcher said "we controlled for confounding variables," there are plenty of people willing to take it at face value.

It's really difficult (maybe not possible) to do that in these large retrospective studies. Shingles vaccine preventing dementia, GLP-1 drugs preventing just about everything, etc, etc. There are plenty of good faith critiques of this kind of work from actual medical researchers making essentially the same point as the OP.


True. But, these are still odd outliers in terms of low life expectancy, and that's something that the actual BMJ article cited (https://www.bmj.com/content/387/bmj-2024-082194) or TFA talks about at all. The LE is low enough for both professions to be awkward.

I'm also a little concerned that the BMJ plot of risk adjusted mortality still shows a clear positive correlation with age at death, which I strongly suspect would turn out to be statistically significant. The adjustment does not appear to be correct, therefore, and while that might still preserve these odd findings, it's definitely not ideal.

The much better occupation, from the graph, is the third outlier -- mining and geological engineers. Life expectancy: 80.3, risk-adjusted mortality: 1.1%. Or, alternatively, economists are close too (80.6; 1.19%).

Aircraft pilots, btw, really were the opposite end of the scale (78.1; 2.3%), surprising enough to be noteworthy beyond a control (the BMJ article does discuss this a little, but seriously -- that's very surprising for a highly-educated profession).


Worth mentioning that controlling for confounders is hard, a reasonable prior is the null effect, and any time a researcher makes a mistake it produces a publication claiming a novel effect. You observe a set of publications concentrated with false positives as a form of selection bias. I wonder how many of the causal studies are reproduced by independent teams using independent datasets.

Plausible scenario. Individuals predisposed to Alzheimer’s experience different mental sharpness from birth and this makes them enjoy taxi driving less (more intense than long-haul trucking), and so they pursue taxi driving as a career at lower rates. Under this scenario, driving has no effect, it just induces a selection bias.


A better low effort contrarian comment - isn't it that early symptoms appear less often with people with a "reserve"?

Being mentally active (or physically active?) IIRC makes actual plaques both less likely, but also less detectable - a taxi driver can forget 90% of what they know and still not get diagnosed because they don't get lost on the way to the shops. Also they are often masters of small talk.


This would suggest they'd need to control for method by which the alzheimer's was discovered. A quick glance seems to indicate they did not do this. This is not information available I guess..

I would suspect this would eliminate a lot of the experiments participants, as only people who go for regular cognitive check-ups might be eligible?

I cannot imagine there would be many people left who'd be eligible. I can only think of 1 person that does it.. and he obviously does it for the pure satisfaction of acing those cognitive tests, and not because he is showing worrying amounts of decline in his mental faculties.


I do wonder if you can truly control for it in this case, or if doing so doesn't in and of itself introduce a survivar bias that masks a reversal of causality. That is: could the taxi drivers who are already predisposed to have a lower chance of developing Alzheimer for other reasons also be the ones who are more likely to live to be older than the average taxi driver?


If the "study" is interesting at all, it's because of the implication that driving a taxi somehow wards off Alzheimers... but at the cost of killing you before you get it.


Just the top one?

Every top-level thread is like a multiple choice armchair takedown.

Here's an interesting counterpoint. "Unthinkable" presented studies of navigation tasks in 2D/3D and testing/training. Hippocampus measurements correlated with skill and training. Interestingly, this skill and training and measurements all correlated with beneficial responses in a disaster (as in, not panicking). Weird right?


But on some level I understand the immediate low level criticism. Of course, it’s stupid to criticize something without reading about it. However, I’ve seen waaaay more studies which was made with even lower effort.

For example, the other day I wanted to figure out what’s the current state about whether gender equality causes measurable benefits for companies… and the studies are terrible. All of them. Most of them was about Norway, and almost all of them had a reference point in 2008, one of the largest economic crisis, and somehow most of them was even worse than this. They openly distorted statistics. Depending on what they wanted to achieve to one way or another. Even the most cited ones. It’s disgusting. The best ones could prove only that inequality is not inherent of economics, but social. But the agenda was different for them too, so they tried to lie something bigger, all the time, while this would be more than enough to support it.


The first question you ask when you read a paper like this is whether you think the authors actually did control for what they say they controlled for. Usually, they didn't.


Don’t worry, doing math can help lower chances of Alzheimer’s, try this website I made on replit: math-mania—ysfrais15rais.replit.app


First time on HN?


And how would you control for the causal possibility that those who will eventually develop Alzheimer's early on might tend to have undetectable memory issues that prevent them from becoming taxi drivers in the first place? You can't control for profession, since that's behind the very claim itself.


Its even worse than that, i can imagine people with undiagnosed early Alzheimer's self selecting for car accidents and cardiac issues through additional stress of mental fatigue while their brain tried to compensate for loss of function.

So you have people self selecting out of the profession, self selecting for early death within the profession, and on top of that, a general life expectancy discrepancy that is near impossible to adjust for.


What happens in the age of self driving cars?


Fewer car accident deaths, leading to more elderly people, which inevitably means a higher population of people with Alzheimers.

(Unless people highly predisposed to dying in car accidents are also highly predisposed to mudering people who will have, but don’t yet have, Alzheimers. But that seems sufficiently unlikely for the purposes of this hypothetical.)

Jokes aside, the serious answer depends on whether the link is causative or merely collerative.


I'm still waiting on someone unbiased to study the data and tell me something. Those who have obvious biases tell me self driving cars are good, but their bias makes them suspect sources. So far I've not found someone without an obvious bias who had the data and is talking.


At one point the amount of human induced accidents will increase since no human can account for sudden erratic brakes of a self driver, even though it predicted a correct incoming accident with another V2V connected car.


No taxi drivers


This is mentioned in the article as well.


As the paper points out that's accounted for in the analysis, because shockingly enough to most internet commentators researchers know that they need to control for confounding variables

https://www.bmj.com/content/387/bmj-2024-082194


Always insane to me how people will just read the headline of an article and point out "flaws" based on what they assume the article says


People jump the gun to show their perceived intellectual superiority. Typically same kind of people are last to admit of a mistake.


It's not necessarily about intellectualism. Science in modern times is plagued by publish or perish. Researchers just need to get things published to keep working, and negative results don't get published. So I think people often publish stuff without proper controls/missing confounding variables/inversion of causality/etc not out of ignorance, but because they know the conclusion is dubious - but if they don't publish, they're going to be out of a job.

I don't think many realize how huge the replication crisis is. You have 75% of studies in a leading social psychology journal failing to replicate. [1] Another replication effort on preclinical medical studies found only 11% were able to be replicated, a replication effort on cancer studies found the average effect size to be 85% lower than published, and much more. If you assume most science headlines, at least outside of the traditional hard sciences, are false - you're substantially more likely to be right than wrong.

[1] - https://en.wikipedia.org/wiki/Replication_crisis#In_psycholo...


> It's not necessarily about intellectualism. Science in modern times is plagued by publish or perish. Researchers just need to get things published to keep working, and negative results don't get published. So I think people often publish stuff without proper controls/missing confounding variables/inversion of causality/etc not out of ignorance, but because they know the conclusion is dubious - but if they don't publish, they're going to be out of a job.

This is very true. In my PhD research, I managed to perfectly predict the placebo effect using a random forest. Now, this was actually due to sampling variance, and the finding went away when I averaged over splits.

I often wonder if I'd still been in academia when this happened, if I would have been able to resist the siren call of a Nature/Science paper (and the consequent career benefits).


Oh wow, I did not know that. Thanks for the input.

I doubt OP's jaded response was alluding to your insight, but still thanks for that, it's genuinely good to know.


And then their comment also reliably becomes the top-voted comment in the post


They got trained to said assumptions by bad sensationalist 'science journalism'. Remember how power lines caused brain damage in children? Not through the magnetic fields or anything like that, but the lowered property values.


You actually read the link ?


> "researchers know that they need to control for confounding variables"

'Why ‟controlling for a variable” doesn't (usually) work' - https://dynomight.net/control/

Other things that don't work, including four other 'controlling for a variable' entries at items 39 through 43: https://dynomight.net/things/



About that old Slate Star Codex article, I find it amazing that no one in that 70+ comment section of presumably smart and Rational people, bothered to look up to see if there were interventional studies on bullying.

Dan Olweus did several of them in the 70s and 80s, and fought to his dying day against programs which didn't have casual intervention studies backing them.


The 1/60 to 1/100 difference could be explained by just one small confounder that is impossible to cover for. Therefore in my opinion making any conclusions based on this study wouldn't be fruitful at all.


The study accounts for that.

Delay your aging by using your brain a fuck ton, all the time, learning brand new things nowhere near anything you already know.


Alzheimer's is an entirely different beast than normal mental atrophy and there are plenty of stories of otherwise intelligent people ending up with it.

I'm not saying you shouldn't try using your brain more but this is just like saying Stephen Hawking should have tried exercising more.


Would this not be closer to saying Arnold Schwarzenegger should have tried exercising more?


Both Stephen Hawking and Arnold Schwarzenegger would have benefitted from exercising more, if controlled for age

/s


The article doesn’t say taxi drivers are immune to Alzheimer’s. It specifically talks about having more cognitive reserve, which means having “more brain” to atrophy. Essentially Alzheimer’s makes their hyper-developed hippocampus become that of an average’s person because they started off higher up.

Being intelligent doesn’t mean you still learn new things as you age. Using your brain doesn’t do anything, it’s using your brain in novel ways.

That companion is also bunk. Two entirely different diseases.


Could just be that whatever factor causes certain cabbies to live much longer than their cohort is also protective from Alzheimer’s. I guess they might have accounted for that too — I’ll have to look at the study.


Or, that if you can survive the thing that kills the rest of their cohort, it has beneficial tradeoffs. As in, perhaps smoking protects from Alzheimer's, if it doesn't kill you first.


Controlling for age in a profession with a high fatality rate like this seems like controlling for high alertness, consciousness, quick reaction times, and well restedness/low stress, low recreational drug and alcohol use.

Of those, sleep issues are highly correlated with Alzheimer's and also with auto accidents. Controlling for age alone here would select for low incidence of sleep issues.


*meant to say conscientiousness (keeping brakes, tires maintained), not consciousness


Collecting a bunch of covariates is never a substitute for recognizing that you can't force people to be taxi drivers for life.


However, you might be able to find a natural experiment were taxi drivers were randomly prevented from continuing with their driving career?


Learning new languages (and actually using them) is a great way to do this for all ages!


I'm bilingual. Learning new languages is pointless if you have no one to talk to in the new language.

Language skills atrophy surprisingly fast.


The claim was learning is important. Not the ability to communicate with it. There are more than 7000 known languages in the world, study a different one every week...

I have no idea what the truth is here...


Back in college (around 15 years ago), I read a few books on eminence by Dean Kieth Simonton. One thing that I remember, and that has always been in the back of my mind, is that certain studies found that (in the USA), children who grow up in bilingual and bicultural households tend to have a much greater chance of achieving some measure of eminence in their adult lives. I am not sure if this is true globally (nor if it is still true in the USA). But I suspect that there is a reason[0] why so many eminent people came from Austria-Hungary for _generations_ (even the generations after the collapse of that particular empire).

[0]: There were 10 distinct languages, making up 98% of all languages in the empire. My understanding is that most citizens had to learn German, even though only 20% of the population spoke German as a mother tongue. Also a few different language branches (Germanic, Ugric, Slavic, Romance), with one of those branches (Ugric) not being Indo-European at all. https://en.wikipedia.org/wiki/Ethnic_and_religious_compositi...


I agree, one must actually use a language for it to contribute to brain plasticity in later ages.


From the article:

    > After adjusting for age, sex, race, ethnicity and education, roughly 1 in 100 taxi and ambulance drivers died of Alzheimer’s, compared with 1 in 60 people overall.
Does that answer your concern?


No. There are a lot of other comments on why many do not believe it.

There is no reason to believe they have enough data to adjust for any of their controls. It looks to me like they plotted everything and then found the "outlier" which statistically we know will exist in a true random sample.


| After adjusting for age, sex, race, ethnicity and education, roughly 1 in 100 taxi and ambulance drivers died of Alzheimer’s, compared with 1 in 60 people overall.

They claim to control for these factors in the 5th paragraph of the article here. Which is a standard thing to do in these kind of studies.

So you're point is either not relevant or that they didn't control for age correctly?


So many possibilities for error...

Is every case of dementia diagnosed accurately? Is there a difference between professions how likely their dementia is to be diagnosed accurately?

Is there a correlation between dying early and being pre-disposed to have developed Alzheimer if having lived longer? If there is, then the "correction" for age is not correct, because the correction assumes the fraction of the group that died early were equally likely as the rest of the group to develop the disease if they had not died early.

I don't know anything about Alzheimer but it doesn't seem unthinkable that the factors that cause people to die early also could also play a role in causing Alzheimer.


You could imagine that pre-diagnosis confusion relating to Alzheimer's increases the risk of traffic accident and kills taxi drivers, too. Might not operate for truckers as much because they're more likely to survive accidents.


Studies typically use regression to account for stuff like that. CBA to look at the article, but I bet any money that's controlled for.


> After adjusting for age, sex, race, ethnicity and education, roughly 1 in 100 taxi and ambulance drivers died of Alzheimer’s, compared with 1 in 60 people overall.

So no indication they accounted for the expected lifespan of the profession.


Adjusting for age seems like an indication to me


It’s insufficient. For example, the people who develop Alzheimer’s may for whatever reason may be less likely to survive the profession where Alzheimer’s is the cause of death (eg getting into a fatal car accident where undiagnosed early onset is the problem). Bus drivers typically drive the same route over and over and probably have safer trips overall than taxi and ambulance drivers.

It’s a plausible hypothesis but it’s really really hard to tease things out and controlling for age is the obvious thing but that doesn’t get you the conclusive result you think it does.


Adjusting for sample/population age is the simplest interpretation of that


Indeed. I feel that although many people try to learn new languages, the intellectual stimulation provided by doing so is understated. Especially learning languages very different from your native language (grammatically, morphologically, etc.). It’s almost like finding new ways to think.


Seems like a fair point.


> CBA to look at the article

then don't post


Mate, you ever read a scientific paper? You dig regression? Did you read TFA yourself? Was I wrong?


Yep. Free solo climbers also rarely die of Alzheimer’s.


BASE jumpers and wing suit fliers too.


That's why I make sure to wear a wing suit at least one day a week.


I am pretty sure that a dataset controlling for that would (laughing here) not negate the fact that fewer people who lived past the mean date that are taxi drivers died of a related disorder.

That said, suggesting it is related to the career as opposed to, say, the fact that a higher percentage of taxi drivers carry some other set of genes or genetic markers that either led them in some way to become a taxi driver or contributed to a lack of development of the disorder, is pretty weak. In the United States and I think a few other countries the number of taxi drivers which are immigrants from a handful of countries outnumbers any other type.

And, the world has changed a lot. Are 1980s cab drivers and 1950s cab drivers and 1965 cab drivers and cab drivers from 2007 comparable? are car service and livery drivers?


That's very interesting but why do taxi drivers have a job that lowers life expectancy? Is it because they're sitting too much? Or because they're inhaling CO from cars too much? Or staying inside (the car) too much? Or is it just stressful?

For from the look of it it doesn't look like an exceptionally hard job (btw a brother of mine did years of "VTC": "Vehicule de Tourisme avec Chauffeur", basically high-end taxis without the "taxi" logo).


I did it, briefly, twenty-some years ago. Lousy job—sitting all day, irregular pay, danger, nasty fares, drunk fares, belligerent fares, fares who seem to have nothing better to do with their days than to find ways to cheat a driver. But the thing that really sucks is the hours: shifts are twelve hours long, either ending or beginning at 3:00am, and because your rental for the cab is highest at the beginning of your work week, descending every successive day (free on day seven), the compensation is structured so that you're making good money only by working a ton of hours.


Because it doesn't pay very well. Being affluent increases life expectancy.


1. They are hardly in the bottom quintile, where the income effect is large enough that it could actually shave 7 years off their life. I'd expect nightly work, irregular sleep patterns, too much fast food and maybe a higher frequency of smoking to do their part.

2. The original study didn't just study taxi drivers, but also ambulance drivers. I doubt that their life expectancy is that much lower.


They are if you consider the amount of hours they work


>For from the look of it it doesn't look like an exceptionally hard job

Define "hard job". Carrying heavy objects?


Stressful on the body.

Odd hours, sitting too much, inhaling too many exhaust fumes, having people yell at you if _they're_ late.

Sounds like a fairly hard job.


Yes, taxi driving can be hard.

There are jobs stressful on the mind too - and some of them have very low "life expectancies".


Lower income, little physical mobility in their job, constantly breathing traffic fumes, and tire and brake dust would be my first suspects.


It’s a very sedentary job, pretty much by definition.


Getting stabbed in the neck by filthy street urchins.


Probably not smart to post something like this on the same message board you’re using to get a job


A joke?


might turn out that the next company they apply to is run by street urchins who don't take too kindly to the stereotype? or possibly humorless scolds who don't want their employees telling jokes in their free time?


>People in these jobs don't live long enough on average to get diagnosed

not to mention the other devil in these studies: some professions are statistically going to have the lowest rate of every possible disease. you can't just cherrypick outliers and declare "causal!"


They are likely studying individuals that retired without getting fatally stabbed or shot on the job.


It's not violence from the job but their job was generally bad for their health in other ways. Sitting all day without getting up and driving around with windows down getting all this UV.

Also, older ones were exposed to a ton of cigarette smoke.


Also road accidents.


I could imagine taxi drivers have fewer fatal/grave road accidents than the average person or at most slightly more. They tend to drive in cities, are more trained, can't drink or do drugs on the job. For London only 1 taxi driver has died in a traffic accident since 2020.


If you drive more you are more likely to be in an accident, that's just how roads and accidents work.

Sure they might be better and per unit of time they drive they must have miniscule amount of accidents.

But if there's a 0.001% chance per hour driven, then over enough hours a few accidents are inevitable.


They don't just add more hours of driving they replace a small amount of risky hours for a lot of hours of low risk if they change location/job.


Also Drivers are generally less likely to die in accidents in urban areas, on high ways it's different.

Pedestrians are a lot more at risk. So that's unsurprising that annually 1/2 taxi driver might be fatally injured in one.

But I would assume the ratio of other drivers to taxi drivers would be high enough that this number should be zero as well.


I'm gonna go out on a limb and say that not even a double digit percentage of taxi drivers' careers are ended due to violent attacks. Taxi driver doesn't even appear in the U.S. Bureau of Labor Statistics top 20 most dangerous jobs.


> not even a double digit percentage

That's actually crazy if that's as low as you dare guess. I would have easily guessed it was like, a fraction of a percent. 1 in 10 would be fucking nuts.


That's like, almost all of them.


survivorship bias


Yepp, they die from circulation related illnesses. Since the sit all day long in the car.


" (...) After adjusting for _age_, sex, race, ethnicity and education, roughly 1 in 100 taxi and ambulance drivers died of Alzheimer’s, compared with 1 in 60 people overall."


Yep.

"For each occupation, we first calculated the percentage of deaths due to Alzheimer’s disease and the mean age at death in years (ie, average life expectancy). We plotted the association between these two variables, with each observation reflecting a single occupation. The purpose of this analysis was to illustrate the need to account for the person’s age at death since the risk of Alzheimer’s disease rises with age and therefore Alzheimer’s mortality would naturally be lower in occupations with a lower life expectancy."


>Taxi Drivers: The mean age at death is approximately 67.8 years.

Where? What country/ies?


In the US, but you’d likely see a similar effect in other places. Taxi drivers are highly sedentary and occupationally exposed to a lot more road pollution than most jobs.


Unsurvivorship bias.


did you read the study


Isn't the mean age simply brought down by the number who die at a very young age due to car accidents, robberies, and other reasons?

Not that cab drivers only live to 67 - many would still live to 75, 85, 95, but that occasionally a driver dies at 25 or 35 bringing the mean figure way down.


[flagged]


?


Ah, the typical cheap HN reaction to a paper, along with "correlation is not causation", and as usual, for things already factored in into it.


Hilarious, because accounting for this stuff is drilled into your head when you study the softer sciences (like psychology) even as an undergrad.


I like how for example if I say contractors can be bad or even awful at their jobs and we'll all nod and agree, but to merely suggest a doctor or someone with a PHD may be, it's blasphemy.


A large part of accounting is knowledge that we cannot control for it.


Next up: "I didn't do a statistical analysis but the sample size seems small"


... in mice!


De Niro is 82, no Alzheimer's. /s


He was method acting, so I'll allow it.


Sleep is a predictor of poverty and poverty is a predictor of mortality.

But i suspect if you hop over the second part there will be more funding in telling poor people to sleep there way to longevity.


> Sleep is a predictor of poverty

Curious. Any sources for this. How does this work? Feel like many high paying, stressful jobs are actually bad for your sleep.



I remember the video nasties of the 90s were 'far from imaginary dangers' for kids, before that it was rock music that the data was screaming at us about. Maybe social media does hold an actual danger this time, but we are a hysterical bunch of knee-jerk reactionary nutjobs, when it comes to new things and kids.

I wouldn't be surprised if 20 years from now we see social media as just another hysterical reaction that generated a generation of bad law, wrecking, or diminishing a number of lives, for no good reason at all.


You're assuming that history has proven the rock music and video games weren't harmful to kids, which I do not grant.


The rebel is just a subset of the second type, and an effective subset if you look at history.

The evil is just a subset of the first type, abuse and use are functionally the same action within a poorly or properly constructed law/policy.


Vitamin D excess can lower blood levels of vitamin K2, reducing bone development. Not sure if the levels would be high enough for this (difficult to find safe numbers for in utero), but the side effects, joint pains, stiffness, could have motivated the kids to stay indoors and focus on more intellectual pursuits, leading to better cognitive performance.

I point this out because there are so many known factors both positive and negative that contribute to increased 'cognitive performance' it is impossible to account for all of them, even within a randomized trail such as this. People are weak to assumptions when it comes to correlation.


I was actually thinking of how tired i was talking to real people and how refreshing AI was to talk something through with.

Most conversations with people, that center around something complicated or emotional are difficult on many levels. I have to deal with humans limited amount of patience and ego eccentric responses that can hide the actual response and require me to untie the persons emotional state diplomatically before i can get to the point.

Just having an entity i can throw concepts at with limitless patience and almost no ego, its really refreshing. The only issue I'm frustrated with is the inevitable Enshittification of these LLMs leading to advertising push or "a response was not generated" popping up whenever something too political or controversial is generated.

I don't consider the massive inflow of IA content in social media as a LLM problem as this is just the same shills that were always on these platforms using AI to increase the quality and quantity of their output, its problems we should have dealt with before AI.


There is nothing that we know of in carbon based structures that violates universal causality, even in quantum scales where causality becomes more vague it is replaced by a measurable randomness.

So there should be no reason we cannot reduce these phenomena to actual quantifiable and there for Computable elements.


Computing something isn’t the same thing as it actually happening.


Its exactly the same, the universe is functionally a computing device, it is based on data and causality. Its complex but our brains do not work deeper than the neuron and so can be modeled in other computing devices like it is modeled in the computing device that is the universe.


That is a dubious asertion. At high enough resolution the model converges on the modeled.


"Resolution" has nothing whatsoever to do with it.

No amount of scribbling graphite onto paper will produce a butterfly.


[citation needed]


\s?


Would you say that displaying image of something on a screen qualifies as actually happening? Writing data on a storage medium? What about a roomba vacuuming a floor?


> Would you say that displaying image of something on a screen qualifies as actually happening?

Yeah, of course.

What I'm addressing is "if we turn 100% of everything about neurons into numbers we can do calculations on those numbers and it's the same as that stuff actually happening with real neurons". Which is entirely wrong. A trajectory calculation isn't different from actually firing a projectile because it's not precise enough but because it's something else entirely.


So are saying that if we made a computer out of neurons that it could be capable of consciousness whereas an electronic one could not?


Yes, brains apparently can do consciousness.

Can descriptions of brains do consciousness? I don't know why we'd expect that they could. You can describe a fire in all the detail you like, and burn nothing.

Can electronic brains be conscious? I dunno. If I had to guess? Sky's-the-limit ignore-all-physical-and-temporal-constraints? Probably. Within the bounds of what humans will ever achieve? Maybe. I doubt they'd look as little-removed from tabulation machines as ours are, though. Like I definitely don't think you get there solving math problems. That would be surprisingly metaphysical.


A fire is something that happens externally and has observable actions. An internal state is not. Your thoughts may take a physical form but that form cannot be demonstrated. Unless you can show me telekinesis then you have only intuition. Why are you so certain that these intuitions are true?


Possibly metaphysical naturalism is wrong and supernatural things exist! And maybe thoughts (and/or the experience of consciousness) are among those supernatural things. That could be it. In which case sure, maybe solving math problems can create consciousness (why not?).


You are attacking a strawman without answering the question.


Do I think supernatural things like thoughts not being represented in physical reality exist? I defer to Russell's Teapot on this one and lean toward "no". If they do, then attempting to reason about anything gets pretty iffy anyway. Who knows what might exist or be true, in that case!


There is nothing that says that if thoughts are not made in brains they must be supernatural. You are making conclusions not based on evidence or argument.


> […] that violates universal causality

I think you're conflating qualia with free will. These are very different concepts, and the experience of qualia has nothing at all to do with "violating causality".

> So there should be no reason we cannot reduce these phenomena to actual quantifiable and there for Computable elements.

As long as we have practically no idea how qualia arise, or even what exactly they are, your claim has no base to stand on.


>As long as we have practically no idea how qualia arise

Qualia or the feeling of consciousness arises from our evolved instinct and ability to personify other humans; turned inward. There is a great amount of evidence to support this from neurological to psychological research.

But even if we didn't know how this came about in the brain, deduction demands it must come about through causal means, which itself is computable and so could be represented in other mediums.


The answer to this is Life Expectancy;

Ambulance Drivers: The mean age at death is approximately 64.2 years.

Taxi Drivers: The mean age at death is approximately 67.8 years.

General Population: in the same dataset, life expectancy averaged 74 years.

The average age at which patients are typically diagnosed with Alzheimer's disease is between 75 and 84 years.

People in these jobs don't live long enough on average to get diagnosed, at the same rate. The same effect will happen in any job that lowers your life expectancy.


Its five years with no limitations, so when you are due to be released; Whats your password? Another five years... Its such a poorly worded law you could literally spend your life in prison for forgetting your password. And Its mostly used against peaceful protesters.


>Its five years with no limitations, so when you are due to be released

Doesn't double jeopardy prevent this? Has this actually happened?


Double jeopardy was abolished by Blair in the Criminal Justice Act 2003, Scotland abolished it as well a bit later in Double Jeopardy Act 2011. However i doubt it would apply even if we had it as the wording in Section 49 is so poor it could just be reissued as a new offense each time.

Has it happened? Section 49 of the Regulation of Investigatory Powers Act 2000 has a secrecy requirement built into it, where if you tell anyone that you have been issued a Section 49 you can get an additional 5 years (treated as a separate crime). This, as you can imagine, makes your question difficult to answer.


It does and of course it's different happened. My pet peeve has to be the "it's a poorly worded law" argument about things that have obviously been considered by legal experts. The scares like "the psychoactive substances act will technically make coffee illegal" I've seen on HN are particularly egregious.


Laws that are so poorly worded that they could be easily misused are bad laws.

Legislators should force future would-be tyrants to flagrantly violate the law, as this is more likely to generate popular resistance.


> Laws that are so poorly worded that they could be easily misused are bad laws.

The point is that these laws aren't badly written. There's already protections in place for what's described above.


I don’t believe this is the case, every now and then we see prosecutors using an obsolete unenforced law or an unexpected edge case of some law to come after people.

A great example is the CFAA. It has been judicially narrowed after court battles, because in its original form it was overbroad and criminalized basic, common things. Prosecutors abused it in order to get political wins until they were finally stopped.

This is unfortunately fairly common. Legislators either push for too much or don’t understand how the law might be applied, and innocent people suffer until someone wins a big expensive set of appeals.

Edit: I realize now you may be talking about the UK in particular, in which case you don’t even get this shoddy level of protection as “Parliament is sovereign” (lol).


I'm talking about the specific law that was being discussed, and the particular other law I used as an example. And the protection mentioned was the one of double jeopardy which had also been explicitly mentioned.


Double jeopardy was partially eliminated in the UK in 2003 for qualifying offenses. I don’t think this has been tested, but during a retrial, a refusal to provide a password would be a separate RIPA offense from any refusal during the first trial. So you could actually be jailed more than once for this. For qualifying offenses all that is required for a retrial is “new and compelling evidence” which is a low hurdle for politically unpopular defendants.


If that did happen you'd have a good case from the Human Rights Act because it becomes indefinite imprisonment. The UK is still following the ECHR as well.

But arguing these theoretical untested-because-they-never-happen edge cases isn't exactly pushing forward a good case for this law having been "badly written." There's seemingly no problem with it in practice.


Dismissing the concerns about poorly worded laws on the basis that they have been considered by legal experts is laughable when it's often legal experts, and in the case of the Psychoactive Substances Act, the government's own advisors that are the ones raising concerns with the broad applicability and unenforceable nature of these controversial laws. The Psychoactive Substances Act has an explicit exemption stating food is not covered by the law for crying out loud, and the exemption for healthcare providers to act within the course of their profession was only added as an amendment, it wasn't even considered in the original drafting of the bill.


> The Psychoactive Substances Act has an explicit exemption stating food is not covered by the law for crying out loud,

Why the "for crying out loud?" That's an example of the law being well written in a way that covers the knee jerk reactions to "it's too broad, it's badly written!"

> the government's own advisors that are the ones raising concerns with the broad applicability

What's your issue with this? They're advisors, it's their job to raise concerns that lead to the inclusion of exemptions like the one you're "crying out loud" about.

> it wasn't even considered in the original drafting of the bill.

That's why bills go through various stages of drafting and debate, and why parliament seeks out and considers the advice from industry. It's "laughable" to judge the quality of a law by the original draft, just as it would be too judge a piece of software by the initial commit.


>ChatGPT (o3): Scored 136 on the Mensa Norway IQ test in April 2025

If you don't want to believe it, you need to change the goal posts; Create a test for intelligence that we can pass better than AI.. since AI is also better at creating test than us maybe we could ask AI to do it, hang on..

>Is there a test that in some way measures intelligence, but that humans generally test better than AI?

Answer:Thinking, Something went wrong and an AI response wasn't generated.

Edit, i managed to get one to answer me; the Abstraction and Reasoning Corpus for Artificial General Intelligence (ARC-AGI). Created by AI researcher François Chollet, this test consists of visual puzzles that require inferring a rule from a few examples and applying it to a new situation.

So we do have A test which is specifically designed for us to pass and AI to fail, where we can currently pass better than AI... hurrah we're smarter!


The validity of IQ tests as a measure of broad intelligence has been in question for far longer than LLMs have existed. And if it’s not a proper test for humans, it’s not a proper test to compare humans to anything else, be it LLMs or chimps.

https://en.wikipedia.org/wiki/Intelligence_quotient#Validity...


To be intelligent is to realise that any test for intelligence is at best a proxy for some parts of it. There's no objective way to measure intelligence as a whole, we can't even objectively define intelligence.


I believe intelligence is difficult to pin down in words but easy to spot intuitively - and so are deltas in intelligence.

E.g watch a Steve jobs interview and a Sam Altman one (at the same age). The difference in the mode of articulation, simplicity in communication, obsession over details etc are huge. This is what superior intelligence to me looks like - you know it when you see it.


>Create a test for intelligence that we can pass better than AI

Easy? The best LLMs score 40% on Butter-Bench [1], while the mean human score is 95%. LLMs struggled the most with multi-step spatial planning and social understanding.

[1] https://arxiv.org/pdf/2510.21860v1


That is really interesting; Though i suspect its just a effect of differing training data, humans are to a larger degree trained on spacial data, while LLMs are trained to a larger degree on raw information and text.

Still it may be lasting limitation if robotics don't catch up to AI anytime soon.

Don't know what to make of the Safety Risks test, threatening to power down AI in order to manipulate it, and most act like we would and comply. fascinating.


>humans are to a larger degree trained on spacial data

you must be completely LLMheaded to say something like that, lol

humans are not trained on spacial data, they are living in the world. humans are very much diffent from silicone chips, and human learning is on another magnitude of complexity compared to a large language model training


Humans are large language models. Maybe the term language is being used a bit liberally here but we basically function in the same way, with the exception of the spacial aspect of our training data.

If this hurts your ego then just know the dataset that you built your ego with was probably flawed and if you can put that LoRA aside and try to process this logically; Our awareness is a scalable emergent property of 1-2 decades of datasets, looking at how neurons vs transistor groups work, there could only be a limited amount of ways to process these sizes of data down to relevant streams. The very fact that training LLMs on our output works, proves our output is a product of LLMs or there wouldn't be patterns to find.


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