Human GPS

December 8, 2011 7:15 PM

"Piloting London’s distinctive black cabs (taxis to everyone else) is no easy feat. To earn the privilege, drivers have to pass an intense intellectual ordeal, known charmingly as The Knowledge. Ever since 1865, they’ve had to memorise the location of every street within six miles of Charing Cross – all 25,000 of the capital’s arteries, veins and capillaries. They also need to know the locations of 20,000 landmarks – museums, police stations, theatres, clubs, and more – and 320 routes that connect everything up." Acquiring The Knowledge changes the brains of those who acquire it.
posted by vidur (73 comments total)

And in Will Self's The Book of Dave, it changes the culture, too!
posted by FLAG (BASTARD WATER.) (Acorus Adulterinus.) at 7:22 PM on December 8, 2011 [5 favorites]

KARA: It was the old knowledge.
KIRK: How do you get the old knowledge?
KARA: I put upon my head the Teacher.
KIRK: What is the Teacher?
KARA: The great Teacher of all the ancient knowledge.

(There is a transparent helmet with what looks like a whole lot of syringes sticking through it.)
posted by RobotVoodooPower at 7:26 PM on December 8, 2011 [1 favorite]

That's really fascinating.
posted by odinsdream at 7:26 PM on December 8, 2011

Having being a passenger in a black cab on a few occasions (drunk trying to figure out how to get back to Kent from the West End), these guys are truly awesome.
posted by RedShrek at 7:30 PM on December 8, 2011

Holy shit "The Knowledge" is the most intimidating name ever.
posted by Saxon Kane at 7:39 PM on December 8, 2011 [10 favorites]

I only knew about this from one of the Hellblazer books featuring Chaz, his driver. The storyline dealt with some of the key areas in London being points that could be used to summon a demon underneath the city.

If the cabbie gets lost, maybe some secret order doles out punishment for misuse of The Knowledge.
posted by FarOutFreak at 7:43 PM on December 8, 2011 [3 favorites]

So cool! I know someone in the US who owns an old black cab. It's so roomy! And fun to ride in. Very, very cool thing about the brains.

Knowledge comes at a cost – taxi drivers find it more difficult to integrate new routes into their existing maps, and other aspects of their memory seemed to suffer.

Maybe this should console me. I have no spatial ability whatsoever.
posted by thelastcamel at 7:46 PM on December 8, 2011

Or, there's GPS. I hired a Brazilian guy with a van to help me move a couple of times and his 'knowledge' was a sultry Portuguese voice emanating from the dashboard: vire à direita em 400 metros ...
posted by Flashman at 7:46 PM on December 8, 2011

I have years of driving experience. My favorite time driving was as a point-to-point car courier in the greater Phoenix metroplex. After a while I had this detailed map of the entire area in my head, and knew "secret" routes which would get me places faster than the intuitive normal routes. I hated living there, but damn, I loved that job.

Somehow, I think I would really love being a black cab driver in London. Simply acquiring The Knowledge sounds like a huge fun game to me.
posted by hippybear at 7:50 PM on December 8, 2011 [2 favorites]

My mom had gotten wind of the initial study shortly before my family and I visited London in 2001. I was made distinctly uncomfortable as, in the back of a black cab, my mom tried to describe to the driver that his brain was swollen in unique and powerful ways. He hadn't heard of these findings, so there was this uncomfortable "oh, is that so?" vibe from him as he was told that his brain was physically different due to his profession.
My mom memorizes number strings recreationally, so she thought the knowledge was simply amazing. He probably didn't like having descriptions of his brain coming from the back of his cab.


That said, I loathe GPS, with a fiery fiery fury.
posted by Cold Lurkey at 7:51 PM on December 8, 2011

That said, I loathe GPS, with a fiery fiery fury.

I made an FPP for that.
posted by vidur at 7:55 PM on December 8, 2011

That said, I loathe GPS, with a fiery fiery fury.

Never been in the middle of the wilderness on a chain of large lakes during an overcast day eh?
posted by edgeways at 7:58 PM on December 8, 2011 [3 favorites]

Cool post. Thanks!
posted by red clover at 8:17 PM on December 8, 2011

I will overlook the dubious neuroscience (what doesn't change the brain?) to note that in the 7 Up series of documentaries, Tony (age 7, age 14, age 21) did the Knowledge and became a successful London cab driver in his twenties.
posted by Nomyte at 8:20 PM on December 8, 2011 [5 favorites]

Never been in the middle of the wilderness on a chain of large lakes during an overcast day eh?

Sorry, to caveat my hyperbole then, I hate GPS based navigation. GPS is essentially fine, in as far as telling you where you are on a map. Telling you where to go, without reckoning on your mode of transportation and conditions is odious, especially in navigable, grid based cities which provide innate orientation if you're attentive to numbers etc.

But Nomyte, this isn't just bullshit activity changes, this is a huge, physical change in the adult brain volume that is distinguishable between knowledgers and not... it's prodigious.
posted by Cold Lurkey at 8:29 PM on December 8, 2011

The Knowledge of a taxi driver's locale should be compulsory if they want to be an authorised taxi driver. I've lost count of the amount of times I've got into a cab and the driver doesn't know where my destination is. I've been asked for post codes, landmarks, and more. I've spent 20 minutes in a cab while the driver phoned a friend to try to find out where he was. If your job is to drive strangers around somewhere where you presumably live, at least have the knowledge of that place. You'd think that as a matter of pride in your job you'd want to know how to get people from one place to the next efficiently. Apparently not.
posted by TheDonF at 8:33 PM on December 8, 2011 [3 favorites]

I'll be damned. Drivers that acquire The Knowledge become significantly poorer at retaining other memories, while their hippocampi actually get physically larger.

It appears, in other words, that your brain can quite literally fill up. No more room!
posted by Malor at 8:34 PM on December 8, 2011 [2 favorites]

"People who like the methodical grid system of Manhattan will whimper and cry at the baffling knot of streets of England’s capital."

So true. Coming from the midwest, where the lines that became streets were laid out before anybody migrated here, I had the hardest time in London. I just memorized routes and followed them blindly, with no map in my head of where I was, until like two weeks before I went home when it all suddenly SNAPPED into place. I swear it gave me a headache. Suddenly the map I'd been looking at and my spatial awareness got together and I could actually navigate.

I think my brain would curl up and die if I had to memorize a city like London. I can't navigate when the grid goes to a 45-degree angle to accommodate a rail line or a river in the midwest. My brain insists all turns are 90-degree turns. Because like 99% of them are, for me.

I'd be sort-of curious to see a study of people like me (I'm not the only one!) who were brought up on a grid and can only navigate a grid system. And then try to make them learn a tangly city. (Although I don't know if an IRB would approve it when the grid-born subjects started curling up and sobbing.)
posted by Eyebrows McGee at 8:34 PM on December 8, 2011 [1 favorite]

I recently had my GPS tell me to avoid traffic by going off I-95 and into gridlock on Broadway in NYC.
posted by dunkadunc at 8:34 PM on December 8, 2011

If your job is to drive strangers around somewhere where you presumably live, at least have the knowledge of that place.

After the train ride from hell, which involved being stuck somewhere in Queens for an extra six hours with a bunch of screaming babies, I arrive in Boston at four o'clock the Monday morning after Thanksgiving, in my freshman year of college. I half-consider just waiting until the T starts running at five but I pay for a cab.

me: "3 Ames Street, Cambridge"
cab driver: "where's that?"
me: "near Kendall Square"
[cab driver eventually figures out where to go...]
cab driver: "what is this place?"
me: "it's MIT."
cab driver: "what's MIT?"
me: "the Massachusetts Institute of Technology"
cab driver: "what's Massachusetts?"

Maybe it's just me, but you should know what state you're in.
posted by madcaptenor at 8:37 PM on December 8, 2011 [6 favorites]

Maybe it's just me, but you should know what state you're in.

I suspect your cab driver knew what state he was in, but that it probably wasn't legal to operate a motor vehicle whilst in that state.
posted by hippybear at 8:47 PM on December 8, 2011 [11 favorites]

Telling you where to go, without reckoning on your mode of transportation and conditions is odious, especially in navigable, grid based cities which provide innate orientation if you're attentive to numbers etc.

Because all GPS navigation systems ignore your mode of transport, and all cities are grid-based.

Seriously, Seattle's nowhere near as bad as London, but in downtown alone, there are three separate, intersecting grid systems, numbered streets running in only one direction (which occasional gaps in which there are named streets between numbered ones), random one-way streets, random turns that aren't legal onto streets that are two-way, random blocks you can't drive down during random hours of the day, lanes that turn into parking lanes with no warning, and street and warning signs that are obscured, oddly located, and otherwise difficult to see. I worked downtown for two years. I still need GPS directions every time I go someplace new there.

And my phone will let me select directions for walking/cycling, bussing, or driving.

Just because you have a good sense of direction and a good memory for streets, and live in a city with a good grid system? Doesn't mean there's something wrong with GPS systems or the people who use them.
posted by MadGastronomer at 8:48 PM on December 8, 2011 [4 favorites]

And my phone will let me select directions for walking/cycling, bussing, or driving.

That's not a feature of GPS. That's a feature of Google Maps. That you happen to have a phone which lets you integrate that service with GPS/triangulation capabilities is a modern miracle.
posted by hippybear at 8:54 PM on December 8, 2011

Well to be fair, NAVIGATION isn't a feature of GPS. It's a feature of some GPS receivers.

That said I've never had one that didn't allow me to specify a mode of transportation, even now-ancient gamins.
posted by flaterik at 9:00 PM on December 8, 2011 [2 favorites]

I tried to ask most of the drivers of the cabs I used in London about The Knowledge. Most of them were happy to talk about it and seemed surprised that I knew what it was called. One guy told me how it took him two years to pass it, and how his family laid out a giant map of London on their dinner table, and how they would study together and quiz him during meals.

An amazing thing. I wonder if I could do it...
posted by m0nm0n at 9:01 PM on December 8, 2011

Hippybear, not only what flaterik said, but if you need a GPS navigation unit that gives you options, you have the option of getting one, so complaining that not all of them have it? Kind of pointless. Pick a model that does.

And ANY GPS system is a modern miracle. What's your point?
posted by MadGastronomer at 9:06 PM on December 8, 2011

Incidentally, "the knowledge" is not a secret or in-joke sort of term. It's right there on the official website.
posted by vidur at 9:11 PM on December 8, 2011

I'm old school, I hate the navigation systems too. But mostly because it's always wrong. "You want me to go down WHAT street for HOW long? You must be crazy."

But then again, I will sit there and read maps for the fun of it. I like using different routes to get to the same place so I can see different things. I like to take a map of a new city and figure out new routes.

I would probably love that job...
posted by gjc at 9:13 PM on December 8, 2011 [1 favorite]

My point is... you're using a phone which has Google Maps available on it.

I've used plenty of GPS units which only show roads and assume transport by automobile.

Are you angry about my comment? You seem to be, when I was simply pointing out that you're using a system which isn't standard GPS unit technology.
posted by hippybear at 9:14 PM on December 8, 2011

When I first moved to London (and continually got lost) someone gave me a great bit of advice, which was to FOLLOW CABS. I did this, and over a decade I basically did my own version of the Knowledge. The map of London that ended up in my brain is really radically different from the one you see on paper or google or the A-Z. It's much more like a tree than a network. I don't have the granularity of a real cabbie (ie I can't get down to individual little streets in arbitrary bits of London) but even having lived away from London for a decade I can close my eyes and, for example, thing what the fastest way from Brixton to Crouch End would be, including the short cuts, without even trying.
posted by unSane at 9:18 PM on December 8, 2011 [1 favorite]

I lived in London for a year after college and remember reading about The Knowledge before I left to go there. One of my guide books mentioned that you'd see guys on motorcycles with maps studying the streets. And sure enough, a few times I saw guys stopped on motorcycles with their maps checking routes. I always wanted to say something to them, ask how it was going and to wish them good luck. I just minded my own business but it is an impressive feat. London's streets change names, there are a million little alley streets, it's a tough city for cabbies.
posted by shoesietart at 9:28 PM on December 8, 2011

I played and lived in London for a little over 10 years back in the late '80s and early '90s. About a month after I got there I asked some friends about all these weird blokes you'd see all over the place on their Honda 50s with the little clipboard on the front. I was informed that they were apprentice cabbies doing "The Knowledge". Apparently they were only allowed to use those little motor scooters in the '70s and onwards, but before that had to do it on a bicycle.

The pub where my mates and I met was in a very, very, obscure working class backstreet of Chelsea with only the pub and a warehouse on it. It was around the corner from Sloane Square, which isn't normally associated with an obscure working class pub. I'd say about a 10th of the time the cabbies didn't know it, but that was the only street, address, cross section, or landmark that they didn't get in my ten years. And they were always so embarrassed about not knowing it that they would offer us the trip for free. We never took them up on that.
posted by Nick Verstayne at 9:34 PM on December 8, 2011 [1 favorite]

It's much more like a tree than a network.

I think that's pretty much true in general. Even if the roads themselves form a network, most of them aren't on the fastest route from anywhere to anywhere, so if you actually look at which routes people use you get something tree-ish. This is even more true, I'd guess, if you look at the routes that any particular person uses.

I find this to even be true in grid cities, like Philadelphia -- even though all the streets are nominally equal, certain streets just tend to move faster. For example if you want to get from Center City to (eastern) South Philly you should take 10th; no lights, and no bus route, so you won't get stuck behind a damn bus.
posted by madcaptenor at 9:39 PM on December 8, 2011

I wrote a master's thesis about The Knowledge and the trainee cabbies trying to learn it. More specifically, it was about an online community that Knowledge Boys and Knowledge Girls (although there are few Knowledge Girls) created to help themselves master the routes and runs that make up The Knowledge.

I published a few papers (here's one) about it and presented at the Association of Internet Researchers a couple of times and was always asked, "How do they do it?" My answer was always, "They spend two years learning with maps and their computers, usually another year or so riding around on a scooter with a clipboard bolted to the handlebars, and then another year reviewing and quizzing each other."

What's most amazing is that not only do they have to know every street, they have to know how to get from any public place to any other public place in London, taking into account time of day, weather, traffic pattern changes, and any other contingency you can imagine. Knowledge Boys & Girls think about London geography in an astoundingly analytical and dynamic fashion.

I really believe learning The Knowledge is the equivalent of a university degree--both in depth and range of knowledge.
posted by yellowcandy at 9:41 PM on December 8, 2011 [33 favorites]

If only university courses were laid out like mental maps! Maybe this suggests a new way that really complicated subjects could be taught - speeding up comprehension by harnessing the power of the expanding hippocampus to memorize a physical representation of concepts connecting to each other.
posted by Kevin Street at 9:48 PM on December 8, 2011 [3 favorites]

Kevin: some math books come with a diagram where there are arrows from chapter X to chapter Y if you need to study X before you study Y. My understanding is that this is officially called a "leitfaden" but I call it a map of the book.
posted by madcaptenor at 9:54 PM on December 8, 2011 [1 favorite]

I'm thinking of something more involved, though. Like making a map of your chosen university major and taking a couple of years to memorize how the concepts connect, just like the would-be cabbies memorize London's streets. Then, after the layout is mastered, drilling down into the concepts themselves.
posted by Kevin Street at 9:59 PM on December 8, 2011 [1 favorite]

It's much more like a tree than a network.

I'd say it's more like a rhizome than a tree, because London includes many villages that used to exist independently, but which have subsequently been taken over by London-the-metropolis. So you'll find multiple pre-existing village and town centres, each with their own high streets, embedded within the more modern overlay of urban and suburban infrastructure.
posted by carter at 10:07 PM on December 8, 2011 [1 favorite]

I'd say it's more like a slime mold than a rhizome.

Oh, wait. I have no idea what I'm talking about.
posted by hippybear at 10:17 PM on December 8, 2011 [1 favorite]

Nomyte: I will overlook the dubious neuroscience (what doesn't change the brain?) to note...

I usually agree with this sort of criticism, and it was my first reaction upon reading the FPP and before clicking through to the article, but now that I've read the article I don't think it applies in this case. The structural anatomy of the cabbies' brains is different, and people with similarly memory-intensive jobs don't have enlarged hippocampi. That doesn't seem like dubious neuroscience at all... it's of a different order than those studies where they just show activation during an MRI scan when people think about love, or whatever.
posted by painquale at 11:19 PM on December 8, 2011

I've lived in Pittsburgh since 1993, and I still find chunks of my mental map undergoing huge revisions. Pittsburgh is not a grid-city; it's more like someone took a grid-city and made a River Tam Bible out of it.

I actually got in an argument a few years ago with someone about which side of the Monongahela River the Waterfront was on, because I was convinced it was on the North bank (it's not). I had to actually look at a map to see that I was wrong, and felt a "Luke, I am your father" level of cognitive disequilibrium until I could sort out all the secondary evidence with what was right in front of me. I had to replay chunks of memory with the new understanding running under them to make sense of what I thought I knew. I spent time over the next few days trying to sort out all the errors.

What these cab drivers do totally amazes me.
posted by Mister Moofoo at 11:20 PM on December 8, 2011 [1 favorite]

But is it worth the effort? I'm wondering about this 4-year preparation and the logistics of it... Do they make enough money to justify the investment, opportunity costs etc?
posted by falameufilho at 12:30 AM on December 9, 2011

Do they make enough money to justify the investment, opportunity costs etc?

I'm sure they have their problems like anyone else these days, but you do tend to see black cabs parked up for the night outside houses across the residential streets (in the bits of south London I know) that are otherwise full of young professional couples and families. They've often been there 30+ years, of course, so they were different streets when they moved in.

The last cab I took was co-owned by two cabbies who took shifts. A cabbie-chat filter might need applying, but the driver said that aside from servicing, their cab's engine had been running continuously for two years.
posted by cromagnon at 12:45 AM on December 9, 2011

The 1979 film The Knowledge starring Nigel Hawthorne, in wich four men attempt to qualify as London taxi drivers, is available on YouTube in 8 parts.
posted by prolific at 1:35 AM on December 9, 2011 [8 favorites]

Oh yeah, I recommend that film - Jack Rosenthal's stuff is always good, and that one is a classic.
posted by Segundus at 1:46 AM on December 9, 2011

Black cab drivers can make about £70,000 ($110,000) per year, and set their own hours, vacation time, etc.

So there's that.
posted by Optamystic at 2:16 AM on December 9, 2011

I was simply pointing out that you're using a system which isn't standard GPS unit technology.

That's kind of silly, though. There's no such thing as "standard GPS unit technology" beyond the ability of GPS receivers to identify your current location, the direction you're moving in, and the velocity of that movement. Anything else - navigation, map overlays, etc - is something in addition to GPS.
posted by me & my monkey at 2:29 AM on December 9, 2011

That said I've never had one that didn't allow me to specify a mode of transportation

My car's built-in/factory nav computer just blithely assumes I will be driving. And to replace it with something less presumptuous I have to buy a new car. :-(
posted by -harlequin- at 2:42 AM on December 9, 2011

There's no such thing as "standard GPS unit technology" beyond the ability of GPS receivers to identify your current location, the direction you're moving in, and the velocity of that movement.

I don't think even direction and velocity are standard. Just position and time.
posted by -harlequin- at 2:44 AM on December 9, 2011

Jens Lekman: Black Cab
posted by 7segment at 2:54 AM on December 9, 2011

I have a friend who is a ship's pilot. He told me that there is a similar sort of knowledge test which part of the qualification process to operate in particular waters. The examiner will give them a precise latitude and longitude for any location within, and substantially beyond, the area they are applying to operate in. Candidates must be able to say exactly what can be found at and around that location. He told me that studying for this test required about a year of studying charts.
posted by rongorongo at 3:00 AM on December 9, 2011 [1 favorite]

The final reward for passing the knowledge? You get to drink your tea and eat your fry-up in one of these... You've probably seen them when wandering around London, but not know what they are - entry can only be gained by having a London Cab Medalion...
posted by benzo8 at 3:01 AM on December 9, 2011 [1 favorite]

-harlequin-: "I don't think even direction and velocity are standard. Just position and time."

Yup, a timestamped 3D location is all a GPS receiver gets. Everything else is calculated by extrapolation.
posted by benzo8 at 3:03 AM on December 9, 2011

Since the GPS receiver is having to track frequency shift of the received data due to Doppler effects of satellite motion using a PLL, it is also able to estimate velocity of the receiver due to any shift that is not explained by the known space vehicle velocity. Given a few SV that are moving in roughly orthogonal basis, the receiver can compute a very accurate 3D velocity estimate based solely on these measurements.

In most units the estimated velocity error is an order of magnitude better than the position error, and modern receivers use a Kalman filter to fuse the Doppler derived velocity estimate and the first derivative of the position estimate.
posted by autopilot at 3:44 AM on December 9, 2011 [2 favorites]

"I'm thinking of something more involved, though. Like making a map of your chosen university major and taking a couple of years to memorize how the concepts connect, just like the would-be cabbies memorize London's streets. Then, after the layout is mastered, drilling down into the concepts themselves."

Kinda like a memory palace? I asked for something similar a few years ago on Ask Mefi.
posted by ollyollyoxenfree at 4:07 AM on December 9, 2011 [1 favorite]

I actually got in an argument a few years ago with someone about which side of the Monongahela River the Waterfront was on, because I was convinced it was on the North bank (it's not). I had to actually look at a map to see that I was wrong, and felt a "Luke, I am your father" level of cognitive disequilibrium until I could sort out all the secondary evidence with what was right in front of me. I had to replay chunks of memory with the new understanding running under them to make sense of what I thought I knew. I spent time over the next few days trying to sort out all the errors.

I have the same problem with Champaign, IL. My internal map got shifted 90 degrees because the exit we used seemed like it went East, but it actually went South. I was intoxicated when I first was informed that I was wrong, and because of that, I still don't believe it 100%.
posted by gjc at 4:31 AM on December 9, 2011

I'd like to see these guys operate in Boston over the past 15 or so years. When I was going to Simmons in the late 90s I'd get on to 93 to follow the route I'd taken the week before and find I was suddenly in a completely different place. Even now that the Big Dig is over I find myself getting tensed up anywhere near Storrow Drive.

My experience with Taxis had largely been in New York City before I went to London last year. I was a bit apprehensive the first time I hailed a cab on my own but found the drivers to be so lovely and so proud of their city. Also, all the drivers I met were intelligible, which I can't say for many Boston or NYC drivers, even the ones who grew up speaking English.
posted by Biblio at 4:46 AM on December 9, 2011

I will overlook the dubious neuroscience (what doesn't change the brain?)

What? What is dubious about this? It's been well established that the hippocampus plays a role in maintaining one's sense of where they are in space. Before I clicked the link I knew they would be talking about the hippocampus.
posted by Jpfed at 4:57 AM on December 9, 2011

benzo8: You've probably seen them when wandering around London, but not know what they are - entry can only be gained by having a London Cab Medalion...

Ah right. I had a Baba Yaga image in my head there until I read it (correctly) as "you've seen them when wandering...
posted by ambrosen at 5:53 AM on December 9, 2011

I've lived in Pittsburgh since 1993, and I still find chunks of my mental map undergoing huge revisions. Pittsburgh is not a grid-city; it's more like someone took a grid-city and made a River Tam Bible out of it.

Ernie Pyle on navigating Pittsburgh:

You may have a friend who lives half a mile away. But to get there you circle three miles around a mountain ridge, cross two bridges, go through a tunnel, follow a valley, skirt the edge of a cliff, and wind up at your friend's back door an hour after dark.

That was from 75 years ago but things haven't really improved and have actually gotten more confusing in places where highways and/or urban development has hacked the grid up even worse. We also have fun features like street numbering schemes that are repeated a mile away causing the 9th street bridge to be nowhere near the 10th street bridge. Some bridges and roads have multiple names and the names on the maps are never ever the ones that the locals use. All the signs for one bridge say "62 Street bridge" when approaching from the south bank but "Flemming Bridge" when approaching from the north side and good luck finding "The Parkway East" on a map.

The building that I work in has an address on Reedsdale Street which would be fine except that Reedsdale actually ends two blocks east of it. Sometime back before 1960 or so, Reedsdale actually did go past the building but when they put Rt 65 through, things got moved around and the building is actually on North Point Drive now. But they never changed the address. The post office seems to be able to figure it out but GPS is hopeless and Taxi drivers are often baffled trying to find the place.

I remember during canvasing for the '08 presidential campaign trying for fifteen minutes to walk to a house that I could see right in front of me but I couldn't for the life of me figure out how to get to because even though it faced on on city street, there were no steps in front of the house and as it turned out, it was only accessible from a narrow alley in the back that you had to walk a block and a half around the corner to get into.

I really pity any taxi driver or pizza guy around here.
posted by octothorpe at 6:03 AM on December 9, 2011

Occasionally typos can be thought provoking; I find the idea of a now ancient gamin to do my navigating intriguing.
posted by Standeck at 6:04 AM on December 9, 2011 [1 favorite]

Memory is an interesting thing (slight tangent alert).

In about 1985 I ran into the mailman that had serviced our street in the early-mid 1960's. Long story short, when I mentioned our last name he recalled our street and house number - as well as events and neighbors from that period. This was in suburbia Los Angeles so lots of houses and lots of people.

While not even close to The Knowledge, the ability to tailor one's abilities to fit one's job - or vice versa - is pretty cool.
posted by Man with Lantern at 6:13 AM on December 9, 2011

Hungry hungry hippocampi.
posted by kirkaracha at 6:34 AM on December 9, 2011 [3 favorites]

falameufolhio beat me to it:

London cabbies routinely make twice or three times the average middle class salary. They can also take advantage of dirt cheap (subsidized) cab rental agencies that charge ~£150-400 per week to rent a black cab. So operating costs can be very, very low.

One thing a lot of cabbies told me is that they could work whenever and as much as they wanted, so their incomes vary pretty widely, but some very hard working cabbies make six-figure incomes. I also met one who lives pretty much full-time in Spain and returns to London where he works three days a month and pockets enough money to pay his expenses in Spain. They're not a wealthy lot on average, but they make the kind of comfortable income that highly-skilled experts should.
posted by yellowcandy at 8:47 AM on December 9, 2011 [3 favorites]

FREE IDEA: A game based on Google Maps. You give it a city, and it picks a random starting point and destination in that city. You pick a route in a choose-your-own-adventure style (Would you turn on A, B, or C streets?), without being shown a map. Finally, when (if) you reach the destination, you're awarded points based on how your route compares to the shortest possible route. It would be great for learning The Knowledge, or the equivalent for any other city.
posted by miyabo at 8:53 AM on December 9, 2011 [2 favorites]

Let me just note the obverse: as a New England boy used to nothing being in a grid, I remember the joy of learning about getting around Chicago as a Northwestern undergrad and the utter relief at being able to figure out where you were just about anywhere there was a street sign and/or the ability to see even a glimpse of Lake Michigan.
posted by briank at 9:12 AM on December 9, 2011 [1 favorite]

and the utter relief at being able to figure out where you were just about anywhere there was a street sign and/or the ability to see even a glimpse of Lake Michigan.

or the sun! I'm amazed at how much it screws with people's heads that when I'm lost in a city and it's sunny, I look for the sun. But it works! You have to know approximately what time of day it is, though, so if you've been in a windowless room for a long time you have a problem.
posted by madcaptenor at 9:56 AM on December 9, 2011

Southeast Asian rickshaw/trishaw drivers also have The Knowledge, but it's even more fantastical, being possessed by the hive mind.

In practice, this involves agreeing to take you where you want to go without hesitation, but then stopping every few minutes to ask another rickshaw/trishaw driver if they've ever heard of it.
posted by Durn Bronzefist at 12:12 PM on December 9, 2011

What's interesting here is that apparently the same changes are not seen in doctors, who clearly learn a lot during medical school.

My guess is that the difference involves the fact that we evolved with a lot of capacity for spacial/navigational memory for obvious hunter/gatherer reasons and the hippocampus is the structure that allows this. Other types of learning aren't going to affect that region so much because it wasn't designed for them.
posted by Maias at 2:38 PM on December 9, 2011

I am by no means an expert on the hippocampus, but I am involved in some research with amnesic participants, so I have had a chance to hang around with other researchers who do know a lot about the hippocampus. Some people think that what the hippocampus is responsible for is not just creating or storing memories, but actually relating pieces of information to one another. For example, if I show you an item you've never seen before and tell you it's called a wug, you need to link the appearance and name information together to be able to identify other wugs in the future. From that perspective, it makes a lot of sense that the size of the hippocampus increases for the cabbies, because the information they're learning is largely relational (where one place is with respect to another). However, it's possible to learn a lot of information without necessarily needing to relate things to one another (e.g., memorizing a list of phone numbers or random words). Presumably, that's why people like memory champions wouldn't show the size increase.
posted by rebel_rebel at 4:06 PM on December 9, 2011 [1 favorite]

Tony from the Up Series, mentioned above, is (was?) a cab driver who shared a car with his wife. If you watch the latest installment of the series you see they made enough money to have a lovely, if modest, remodeled home with a conservatory room in a nice neighborhood, and also a second home in Spain. They've done pretty well financially, especially for people who grew up poor east Londoners!

Great post! This is fascinating.
posted by apricot at 5:47 AM on December 10, 2011

unSane: "even having lived away from London for a decade I can close my eyes and, for example, thing what the fastest way from Brixton to Crouch End would be, including the short cuts, without even trying."

Oh, I'd be careful around Crouch End....
posted by Chrysostom at 7:40 PM on December 13, 2011

I've long said that "The Knowledge" is the most awesome name possible for a Mod Revival band.
posted by kimota at 5:55 PM on December 14, 2011