Digit span of 16 (IQ)

Some background:
I wanted to know what my digit span was and how I would score on the subtest. In a professional IQ test, they speak random digits at a rate of 1 per second and every time you recall them correctly, another random string of digits is spoken but this time with 1 more digit and this repeats until you fail twice. Most people score a digit span of 7, plus or minus 2. I tested myself with this app on my phone and I used to score around 13 at first, sometimes 14, because I have not been busy with numbers the last few months so I am rusty, the numbers weren’t very clear and I couldn’t feel them properly. However, now a couple of weeks later, without doing anything other than some small 2 by 2 or 3 by 3 multiplications once every few days just for fun like I always do, I can score around 15 digits, 16 digits is the highest I’ve done. The numbers are clearer now and I can feel them more and this could explain why I score much higher now but would this count on an IQ test?

I don’t think this is the practice effect because the vividness and feelings of numbers changes all the time to me. Sometimes I have bad days where the numbers feel so distant and sometimes I have good days and the numbers are as clear and fluid as water without me doing anything. My mood also plays a significant role and my energy, if I am tired then of course I am going to perform worse like everyone else. I don’t know if 13 is my digit span or 15/16 and I feel like I can even score higher if I try to. If a digit span of 14 correlates to someone with an IQ of 160 (160 is the ceiling for most professional IQ tests) then what the heck would a 16 digit span mean?

I checked if it was the practice effect, perhaps I got used to the voice I heard on the app or something so I changed the voice and accent, still english but it didn’t change anything, I scored 15 again. 15 and especially 16 digits seems extremely high. I can’t find anyone who scored 16 digits on the digit span subtest except people who used mnemonic devices and techniques. If I look at my calculating abilities and memory it makes sense for me to have a high digit span but I have noone to compare myself to with these high scores. To put this in perspective, Rudiger Gamm had a forward digit span of 11 and a backwards digit span of 12.

This guy! ^

I already scored 13/14 when I couldn’t feel the numbers very well, now I score 15/16. I don’t even see or repeat the numbers out loud, I just hear them and try to remember them in my head. I feel like I can go as far as 20 which would be crazy since 16 digits is already double the average and then some.


Once you factor in memory techniques, this test of digit span doesn’t make much sense anymore as a predictor of IQ. There’s actually a discipline at every memory sports competition where exactly this is tested (100/200/500 digits read aloud | 1 digit per second | your score is the number of correctly recalled digits until the first error), and there are more than 1000 people who have scored 16 or higher. @LociInTheSky even correctly recalled 456 digits in the correct order in a competition a few years ago.

Good job with your current score. It’s quite tricky to catch up with the speed in the beginning, but once you get used to it, you’ll soon notice that you’ll be able to go a lot further! :slight_smile:

If you search for “Spoken Numbers” here on the forum, you can also find some programs/websites/apps where you can practice more on this if you are interested.


I don’t think you understand. I don’t use techniques! :joy:


But what exactly is your point? You’ve asked:

I don’t exactly understand what it is you want to compare… @FlorianMinges already pointed out:


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Of course digit span doesn’t make sense when you factor in memory techniques but I am talking about a 16 digit span without techniques so inbetween the rules of the IQ test, what would it mean then?

I can’t find much about people who are naturally “off the charts” but get capped in an IQ test due to the ceilings of subtests like how a lot of IQ test have 14 as the digit span ceiling. I remember in a documentary about Kim Peek that they tested his digit span and they only went to like 11 digits which was disappointing. Like, why only go to 11 when Kim can probably go much further? Why not explore his mind with much more digits and try to find out its correlation with other things, like IQ? If they did then I would know more about my digit span too.

When people score the maximum on a test they just get a +, like 160+ IQ but that doesn’t cover the complete extend of someone’s ability. Imagine scoring an IQ of 140 on a test but on one of the subtest you scored the maximum but you know you can go much further than the maximum of the subtest. This means that your score of 140 isn’t actually accurate.

I thought maybe one of you guys happen to know something about situations like these and if possible, in particular digit span.

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Rules? Where does it say that you are not allowed to use mnemonics?

There isn’t any… IQ is made up. It’s a proxy that is used for academic performance. Which in turn is supposed to be some sort of indicator as to how you’ll do in the job market. Ultimately, that’s an indicator then as far as how much money you’ll make… and finally, money buys happiness.

If this somehow spawns a “high score club” like Mensa… so what… a light bulb generates heat but that’s just accidental. A light bulb’s purpose is to generate light, the heat is just a byproduct. The point of an IQ test is not to see if you’re 4, 5, 6, etc. σ to the right of μ.

What would you know? Just like using mnemonics… savantism or being a prodigy or whatever you wanna call it is not considered as far as the test design. It’s not gonna tell you anything.

If water boils at 100℃… does it boil twice as much at 200℃? Again, that’s not what the test is designed for.


It is what it is designed for. If it tries to conclude something by measuring certain things and you happen to excell far beyond the maximum of one of those certain things then it should take that into consideration if it wants a somewhat accurate conclusion. An example would be giving someone an average IQ score but completely ignoring that that person has an eidetic memory as if that won’t have an impact at all in life.

IQ tests are also not only made for prediction in the jobmarket. They’re also made as an indicator for diagnosis. E.g. if you have a kid that struggles in school then you can let that kid take an IQ test for insight as to what is going on. They can even be used for autism.

It’s too bad that situations like these aren’t fully explored. As soon as you score the maximum you get swiped into the same category as everyone else who got the maximum, even though the difference could still be huge between those who scored the maximum. If they could differentiate those at the high end as well then IQ would be an even better predictor.

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They have many digit span components. There is backwards as well as forwards. Maxing out on those as well as any other WMI components gives you a maximised WMI index. If you then max out or close to for other components, then you have a FSIQ of 160.

They also have extended norms, which measure IQ’s up to 210 but I believe this is usually done for people under the age of 16 exclusively and restricted the older you are up to 17 (16 and 11 months).

I believe they updated the cap on the digit span to something like 15-16. I don’t see any extended scales for their new formats (they do have them) but they struggle with testing higher abilities and don’t find much significance in doing so (no occupation that requires minimum 160 besides specialised IQ societies with their own tests). Commonly it is said that after 160 there is a difference that is no longer measurable by standard procedures. I can’t find precise data on the cap for the extended formats but I would assume the cap may actually be the extended cap and the real non-extended cap is something lower.

Most systems of education aren’t designed for people with scores above 130-145, neither are most job prospects. Above average but not too much is going to be the average person who can meet all the requirements of the system and still abide by it.

One of the issue with simply extending scores besides any cheating under the context of mnemonics or otherwise is that you will generally fail to design a test which doesn’t have multiple answers and also that progressively accounts for everyone. There are also too few people at those ranges who actually can give you any information on what happens at those ranges.

Working memory runs into the ‘mnemonic’ issue at higher scores. With mnemonics after 400 digits what score are you going to give the person? If you accuse them of using mnemonics and they say they are not, what do you do then? Some people use mnemonics without knowing what mnemonics are and score around 30’s, in some clinical cases up to 80. People who use visualised soroban to high expertise in general tend to have a span of around 16.

Personally I don’t believe in IQ scores so I am stating everything before the line without my own bias. I mean it would be nice if you can take a test and then be given a lab, unlimited funds and a world class library and full privacy to experiment with because of your result. At that point it doesn’t matter what the cap is you can be sure I would be taking the exam to it.

Putting the humour aside, in short you would like it for there to be recognition for higher general ability.
Being able to have IQ scores up to 500, would definitely be better than capping them at ranges which people meet or pass by.

The easiest recognition is just to beat everyone else at every field in the world. If you win the nobel prize, people will start saying you have an IQ of 160+, if you outperform someone who is believed to have a high IQ e.g Terence Tao, people will put your score on +10 of what his is. With some publicity you can then make a bold statement like, ‘I have an IQ of 300’. While people will be sceptic it will start seeping into media and belief. Once you have some cross field achievements you can start making claims like ‘you have increased your IQ to X’. While some will be in disbelief once you have the results no one is really going to argue much. If you tell them you can fly without machinery some will actually believe you at that point. Contrarily, prior to any achievements , few will take you seriously regardless.

Unlike AI (real AGI which doesn’t exist yet), there is no general common most efficient algorithm people employ for their actions as of yet, so there will be vast differences with people who have the same higher capacities to do things. Although people often make simple invariant choices the choices you make can greatly impact your own display of ability. For example if I did a digit span test and I used only my visual sketchpad rather than any auditory cue, or I didn’t chunk or chunked in a certain way , my digit span would differ a lot. These things are very normal things to do, I’m not even including abnormal procedures such as visualising the string of numbers in unique colours as they are called and any background earworms you currently have while doing so. In life you will make these kind of unlimited choices always and even your past choices can impact your future ones.

All this said, its kind of off point from your topic. There are likely people with digit spans around 16 without mnemonics or special techniques. I once was learning a little too much for a day and had a digit span of 16 for 1 day (the next day) with 0 repetitions. Since I didn’t do much with digits the day before and also had an increased sentence span I could assume it was general. Sadly it only lasted a day and I was too tired to employ much spaced repetition for learning on that day to keep the result up. It was a really nice experience though, I might try this again.

It’s true that your digit span is correlated with the maximum on tests. Someone who is believed to have an IQ of 210 might not even have a digit span of 16. If it was one of their most prominent results they may however have a high digit span without techniques.

Such are IQ tests.

One of my teachers in secondary school had a certified IQ of 160, I was really the only one who looked forward to his classes. Even though he was the only good teacher I had, he wasn’t really respected by anyone, not even made head of faculty (when he really should have been). Even though I don’t really believe in IQ tests it’s obvious to me by meeting him that he isn’t like the people in class or other teachers. In a different school I also had 2 people in my class who also weren’t very much like others. Irrespective of IQ tests it’s obvious that those 3 were significantly intelligent compared to average. In terms of natural digit span/natural memory I believe you would have a higher digit span and memory than all 3 of those. Better memory than a graduate chemist, 1st rank in a top region university for his subject and someone better than the first two. It’s not really my place to judge over but factually it is true. I will also say that one of them has a memory so bad that it actually helps them, you can never know.

I assume from the perspective of the test designers they may justify this as, if the component wasn’t able to improve the other components then it is being limited by the other components for any other tasks so therefore not valid as an impact on the score beyond the cap. I will highlight that people do not understand intelligence, making a test on something you don’t understand was never going to end well. If you followed the research and theorising as well as ideas and philosophy that they use to establish IQ tests, you quickly notice the fallacies.

Kim was tested to 87 IQ, clearly has abilities that don’t quite justify this. Again such is IQ testing. I don’t believe in IQ tests for reasons such as these amongst others.


Dammit Nagime, you never disappoint :slight_smile:

Thank you for your response. I didn’t know that some have updated the digit span test to 15/16 digits.
I find forward digit span harder than backwards digit span.


I find it hard to believe that after a few more times he immediately increased his digit span. I believe he can increase his digit span but not that quickly. If it was over several days or weeks then I can see that.

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Or do you mean like after some time that he increased his digit span? I might be misunderstanding because when I see the word “few” I think like 3 or 4.

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I believe this was the reference.

The mind-numbing memory exam that SF, the Carnegie Mellon undergraduate, took over
and over again for 250 hours for two years is known as the digit span test. It is a standard
measure of a person’s working-memory capacity for numbers. Most people who are given
the test are like SF when he started: They’re only able to remember seven plus-or-minus two
digits. Most people remember those seven plus-or-minus two numbers by repeating them
over and over again to themselves in the “phonological loop,” which is just a fancy name for
the little voice that we can hear inside our head when we talk to ourselves. The phonological
loop acts as an echo, producing a short-term memory buffer that can store sounds just a
couple seconds, if we’re not rehearsing them. When he began participating in Chase and
Ericsson’s experiment, SF also used his phonological loop to store information. And for a long
time his scores on the test didn’t improve. But then something happened. After hours of testing, SF’s scores started inching up. One day he remembered ten digits. The next day it was
eleven. The number of digits he could recall kept rising steadily. He had made a discovery:
Even if his short-term memory was limited, he’d figured out a way to store information directly
in long-term memory. It involved a technique called chunking.
Chunking is a way to decrease the number of items you have to remember by increasing
the size of each item. Chunking is the reason that phone numbers are broken into two parts
plus an area code and that credit card numbers are split into groups of four. And chunking is
extremely relevant to the question of why experts so often have such exceptional memories.
The classic explanation of chunking involves language. If you were asked to memorize the
twenty-two letters HEADSHOULDERS-KNEESTOES, and you didn’t notice what they spelled,
you’d almost certainly have a tough time with it. But break up those twenty-two letters into
four chunks—HEAD, SHOULDERS, KNEES, and TOES—and the task becomes a whole lot
easier. And if you happen to know the full nursery rhyme, the line “Head, shoulders, knees,
and toes” can effectively be treated like one single chunk. The same can be done with numbers. The twelve-digit numerical string 120741091101 is pretty hard to remember. Break it into four chunks—120, 741, 091, 101—and it becomes a little easier. Turn it into two chunks,
12/07/41 and 09/11/01, and they’re almost impossible to forget. You could even turn those
dates into a single chunk of information by remembering it as “the two big surprise attacks on
American soil.”
Notice that the process of chunking takes seemingly meaningless information and reinterprets it in light of information that is already stored away somewhere in our long-term
memory. If you didn’t know the dates of Pearl Harbor or September 11, you’d never be able to
chunk that twelve-digit numerical string. If you spoke Swahili and not English, the nursery
rhyme would remain a jumble of letters. In other words, when it comes to chunking—and to
our memory more broadly—what we already know determines what we’re able to learn.
Though he’d never been properly taught the technique of chunking, SF figured it out on
his own. An avid runner, he began thinking of the strings of random numbers as running
times. For example 3,492 was turned into “3 minutes and 49 point 2 seconds, near worldrecord mile time.” And 4,131 became “4 minutes, 13 point 1 seconds, a mile time.” SF didn’t
know anything about the random numbers he had to memorize, but he did know about running. He discovered that he could take meaningless bits of information, run them through a filter that applied meaning to them, and make that information much stickier. He had taken his
past experiences and used them to shape how he perceived the present. He was using associations in his long-term memory to see the numbers differently.
This, of course, is what all experts do: They use their memories to see the world differently. Over many years, they build up a bank of experience that shapes how they perceive
new information


SF, Ericsson’s work-study undergraduate
who expanded his digit span tenfold, had not increased some generalized memory capacity.
Rather, he’d simply become an expert at digit memorization. When he tried to memorize lists
of random consonants, he could still only remember about seven of them.


Nagime again with the clutch.

So this “SF” person was basically almost using mnemonics. He associated random numbers to meaningful things from his life, like running times. He also spend 250 hours in two years practising, damn that’s long.

Here is where I differ from “SF”. He associated random numbers to other things and chunks them that way. I just chunk them because I prefer the numbers in a certain way, I don’t associate them with anything. I prefer 48-927 over 4-8-9-2-7 because that feels right, nothing else. 927 is a nice and polite number and 48 is this background number. 48 is like a side or background character. Both these numbers aren’t even that special to me, not like 27 for example, 27 is wicked smart. 127 is a cognitive powerhouse, a monster. If 127 was real than he would have an IQ around 275.


I don’t see the flaw though? 13 digits seems to be my minimum. When SF started, the amount of digits he could hold was around 7 digits, which is average. My minimum is almost double his score. I was already ahead of SF in that regard. He had to practice a lot and find a way to match my minimum. It doesn’t matter now if he can recall 14 digits or 114, when we are both in our “normal state” which I always am, SF can’t keep up.

My digit span seems to be inbetween 13 and 16 digits, at least right now, I don’t know if it will increase again in the future, perhaps it will even go down!

My specialty is in numbers but I don’t know what qualifies as talent. Talent is one of those vague subjects. Like art… or IQ :stuck_out_tongue:

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Yes cx

What you did was memorizing. Memory is a part of intelligence but not everything. The reason something as memorizing the answers wouldn’t count as being more intelligent is because almost anybody could do that but the test is made in a way to find out how you distinct from people in certain aspects and how much you distinct from them. If you memorize the answers which almost anybody could do then your results would not be valid since you didn’t do the test in the way it should be done in order to find how you distinct from others. If the person who scored 90% would also memorize his answers then his score would be invalid too. You both would have invalid scores, which would be useless for the test, even if it wasn’t about intelligence.

It would be like using inline skates in a distance running test which point is to find out how well your condition is. Sure the skates makes you faster but that is not helping the point of the test at all. You didn’t really give the test the chance to “test” you in the way the test wants.

I removed my posts.

If you only want to evade the points I make that show that a test like you mentioned is invalid, and just keep telling how “intelligent” you are by nitpicking the details that dont matter at all, I am done.

There is no discussing if you only want people to praise your accomplishment.


What? What are you talking about? I am not evading your points? I agreed with you that you can train to improve your digit span without mnemonics, I just didn’t believe it could happen after 3 or 4 tries and it didn’t happen, it took much longer apparently. And I agreed with other things as well but I don’t know what since you removed your posts.

I am not defending IQ tests here. If you read my previous posts, you will see that I point out some flaws in IQ tests as well. You even agreed with one of them.
This whole thread’s point was to find out what a 16 digit span could mean in an IQ test that often only goes to 14 digits. I needed to know because I am going to take an “intelligence” test soon in the future and I am afraid that some of my abilities or a lot of them will be capped on the test like my digit span and arithmetic skills. Because when it comes to things like that I excell far beyond the norm, even far beyond people with an IQ of 160 and I can’t get over the fact that it might be capped without seeing the full extend of it. I feel like it wouldn’t make my results valid. Fortunately Nagime cleared some things up by mentioning how some tests have updated their digit span to 15/16. Like @bjoern.gumboldt said, savantism, which this could be, gets tossed aside just like mnemonics which is not fair. Savantism is innate yet an IQ test won’t recognize that because it’s too far beyond the norm or too rare so it gets capped off. It’s exactly what I said about scoring an average IQ without recognizing the fact of someone having an eidetic memory which could play a significant role in life and succes, something IQ also is about but this gets ignored. It sucks.


You’re working memory is in the 99.999%. Extremely rare but not impossible. A good friend of mine is the same. He too can memorise 14 digits (I tested him myself). He got his IQ tested (because he did poorly at school when all his teachers said he came across like a really bright guy) and according to him the psychologist didn’t want to believe him that he didn’t use any techniques and said that this was the highest score he‘s ever experienced in his career up to that point to give you some perspective about how good such a digit span is.
So yes, as I’ve witnessed it with my own eyes I know it‘s possible to have a digit span of 14 even without practice and mnemonic techniques. Feel lucky!


Incredible. Sucks that the psychologist didn’t believe him, I hope this won’t happen to me as well. Do you know what your friend’s IQ score was?

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Just a few weeks ago, I showed off my training result in memorising numbers to a classmate, when he did, he went 22numbers (he is studying anatomy currently as well, perhaps that helped somewhat?)! and I know he knows nothing about mnemonic! Was begging him to train with me to woop A$$ in the memory world, but interestingly he had trouble adapting to mnemonic technique for a bit XD

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