Taxi drivers rarely die of Alzheimer's • Hacker News Board

Re: Taxi drivers rarely die of Alzheimer's

#91

Post by boelboel » Sun, Aug 09, 2026, 9:41 PM UTC

minraws wrote: post #46

stackskipton wrote: post #43

Earlier quoted context omitted.

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.

Re: Taxi drivers rarely die of Alzheimer's

#92

Post by boelboel » Sun, Aug 09, 2026, 9:44 PM UTC

xvedejas wrote: post #89

cortic wrote: post #30

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.

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.

This is mentioned in the article as well.

Re: Taxi drivers rarely die of Alzheimer's

#93

Post by estetlinus » Sun, Aug 09, 2026, 9:50 PM UTC

> London cabbies must memorize more than 25,000 streets within a 6-mile radius of Charing Cross, a challenge known as “The Knowledge” that takes three to four years.

What the hell. I passed all the test for driving cabs in Stockholm, Sweden. I had to memorize 20 regions in the city. I wonder if this requirement applies to all taxi drivers, including Uber.

Re: Taxi drivers rarely die of Alzheimer's

#94

Post by cortic » Sun, Aug 09, 2026, 9:51 PM UTC

xvedejas wrote: post #89

cortic wrote: post #30

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.

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.

Re: Taxi drivers rarely die of Alzheimer's

#95

Post by monster_truck » Sun, Aug 09, 2026, 9:57 PM UTC

genxy wrote: post #47

walthamstow wrote: post #12

> In one landmark 2000 study, neuroscientists compared the brains of licensed London taxi drivers with those of people who did not drive cabs. Location is very important here. London cabbies have to pass The Knowledge which is an extremely difficult memory exam that only people with particular kind of brain can do.

People who would pass The Knowledge test might already develop dementia at a much lower rate.

They could also develop it at the exact same rate and mask it effectively. Had a very sharp family member who was completely lucid through all of dementia, it was like watching a tape rewind. Got to meet each decade's version of them over a couple of years. Towards the end they were completely normal

Re: Taxi drivers rarely die of Alzheimer's

#96

Post by jerlam » Sun, Aug 09, 2026, 9:58 PM UTC

SoftTalker wrote: post #17

artisinal wrote: post #13

Earlier quoted context omitted.

Indeed. Elsewhere in the world taxi drivers just follow the GPS.

We had taxis long before GPS. When I was in my early 20s I had a job delivering pizza. I very quickly learned the delivery area, I knew pretty much every street and alleyway and shortcut to get from one place to another. Much smaller than London but I think the human brain is very good at remembering routes and where things are in an area, as this would have been an evolutionary advantage (go out hunting and be able…

There weren't a lot of taxis outside of major cities. I think widespread GPS allows ridesharing apps like Uber and Lyft to exist in suburbs and other places where taxis weren't a thing before, because it dramatically lowers the bar.

Re: Taxi drivers rarely die of Alzheimer's

#97

Post by pama » Sun, Aug 09, 2026, 10:01 PM UTC

yfontana wrote: post #69

Something interesting that the original study looked at, but isn't mentioned in the linked article: this effect was not observed for non-Alzheimer's dementia deaths. There seems to be something specific to spatial reasoning and Alzheimer's.

Alzheimers has a very long development stage compared to almost all other dementia (Lewis body also has a long timeline, but none of the other forms has anywhere close to the known length for Alzheimer’s disease). The original study article has no causal analysis, so a simple explanation is that super early Alzheimers symptoms (possibly even undetectable ones outside the context of intense taxi driving) drives people to abandon their taxi- or ambulance-driving jobs and seek other forms of employment.

Re: Taxi drivers rarely die of Alzheimer's

#98

Post by markdown » Sun, Aug 09, 2026, 10:04 PM UTC

glitchc wrote: post #40

cortic wrote: post #30

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.

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

That's like, almost all of them.

Re: Taxi drivers rarely die of Alzheimer's

#99

Post by minraws » Sun, Aug 09, 2026, 10:21 PM UTC

boelboel wrote: post #91

minraws wrote: post #46

Earlier quoted context omitted.

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.

Re: Taxi drivers rarely die of Alzheimer's

#100

Post by minraws » Sun, Aug 09, 2026, 10:25 PM UTC

boelboel wrote: post #91

minraws wrote: post #46

Earlier quoted context omitted.

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.

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.