Surprisingly, the image below is readable to humans. It is not a specific language. How is this possible?

enter image description here

1N73LL1G3NC3 15 7H3 4B1L17Y 70 4D4P7 70 CH4NG3.

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    It's called leetspeak: en.m.wikipedia.org/wiki/Leet
    – jazZRo
    Commented Jun 13, 2017 at 6:17
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    It is a very specific language. It is called English. It has been the fact that it uses non-standard symbols for some of the characters doe not make it "not English" all of a sudden.
    – oerkelens
    Commented Jun 13, 2017 at 7:35
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    You can read that? Commented Jun 13, 2017 at 9:28
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    @CodyGray It took me a second but just look at the first word as a whole instead of character by character, once you get the first word the rest just fall into place.
    – DasBeasto
    Commented Jun 13, 2017 at 12:02
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    I'm voting to close this question as off-topic because this is related to neurosciences rather than UX. This question could be moved to cogsci.stackexchange.com
    – Devin
    Commented Jun 13, 2017 at 16:51

3 Answers 3


This is psychology

Humans are the World's Best Pattern-Recognition Machines. Quite simply, humans are amazing pattern-recognition machines. They have the ability to recognize many different types of patterns - and then transform these "recursive probabilistic fractals" into concrete, actionable steps. If you've ever watched a toddler learn words and concepts, you can almost see the brain neurons firing as the small child starts to recognize patterns for differentiating between objects. Read more.

Research article from cambridge university states:

  1. Psycholinguistic evidence on scrambled letters in reading

  2. It deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoatnt tihng is taht the frist and lsat ltteer be at the rghit pclae... it doesn't matter in what order the letters in a word are, the only important thing is that the first and last letter be at the right place

  3. the rset can be a toatl mses and you can sitll raed it wouthit porbelm... the rest can be a total mess and you can still read it without problem

  4. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe... This is because the human mind does not read every letter by itself by the word as a whole.

Other article

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    For your last point: we don't just read whole words - we also read sequences of them (normally up to 5) in order to do further recognition and error correction.
    – adelphus
    Commented Jun 13, 2017 at 8:45
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    "the only important thing is that the first and last letter be at the right place" uoiinnnnccvg, ueeirrttsncd slbnmcraig is piaoelbmtrc. I'd say it becomes a lot harder the more the letters are rearranged.
    – Joren
    Commented Jun 13, 2017 at 10:27
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    "humans are amazing pattern-recognition machines" -- very true, but sometimes we're too good at it ... patterns in ink-blots, faces in clouds. The brain doesn't like true randomness and will often "find" a pattern that isn't there.
    – TripeHound
    Commented Jun 13, 2017 at 10:55
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    Note that the Cambridge research article debunks some of the points in that scrambled text that was widely circulated some years ago, specifically it says point 2) is "clearly wrong".
    – JJJ
    Commented Jun 13, 2017 at 11:55
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    More than 50% of this answer is taken up by a quote that is plain false, and which is debunked by the link you provide. In fact, your wording implies that the link supports the quote, rather than debunking it. Please change this. Commented Jun 13, 2017 at 12:58

Because our brains are highly adept at recognizing patterns.

To speed things up a bit, our brains gather a lot of data in one go, and attempt to descipher it in stages. The first stage is very quick - it takes the overall shape of a word (high emphasis on start and end letters) and matches it to a word it already knows.

As such, 3 and E are alike, but "flipped", so our brain can adapt to that difference. Same for A and 4. 5 and S. T and 7. O and 0. Some of these are obvious, others slightly less so.

It's the same tihng taht lets us raed tihs lien wtihuot too mcuh effrot!

In fact, you didn't notice that in thise Iine, I swapped the capital i and lowercase L's around on the emphasised words... it's the same principle!

Also, I'm pretty sure that's in English - it's just got some letters swapped out for numbers!

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    I don't know if you shuffled the last letter of "line" intentionally, but it works extra well because I read it and stumbled for a split second on that word.
    – Erik
    Commented Jun 13, 2017 at 8:38
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    @Erik also the fact that misspelling is a word in its own right causes a pause.
    – Chris H
    Commented Jun 13, 2017 at 8:47
  • @ChrisH now we all understand dyslexia.
    – user67695
    Commented Jun 13, 2017 at 14:41
  • If the image in the OP is English, then the result of enciphering English text using a substitution cipher is English. And if your penultimate paragraph is English, then the result of enciphering English text using a transposition cipher is English. How strong a cipher must be used on English text for you not to claim that the ciphertext is English?
    – Rosie F
    Commented Jun 13, 2017 at 16:58
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    @RosieF I would argue that the image in the OP isn't really a substitution cipher (or maybe a trivial one at most) in the normal sense because that the symbols being substituted are intentionally visually similar to the originals. So it's more like bad handwriting or a weird font. Commented Jun 13, 2017 at 21:23

We have evolved to recognize patterns, to be able to apply a greater amount of detail to something where we don't have a lot of accurate detail, by making assumptions.

For example, we recognize faces at a distance because we can abstract it away to a very basic structure with very little detail. This is why a colon and a parenthesis can look like a happy or a sad face (depending on which parenthesis you use.) :) :( The two dots are close enough to our abstract idea of eyes, and the curved line is close enough to our abstract idea of a mouth. I could add a dash and that would be close enough to our abstract idea of a nose. :-)

The more we add details, the less our brain has to make corrections and assumptions, so if someone paints a face using shading and color, then we can see a face in deliberately placed brushstrokes, or in our digital age, in thousands (or even millions) of deliberately colored pixels.

This is similar to a thing called pareidolia which is an effect that we're constantly being fooled by. It's how we confuse ourselves into thinking we see a face in objects that are obviously not meant to have faces (for example, a famous rock formation on Mars)

Mars Face

We developed this technique due to our tribal history. Being able to recognize faces from a distance in low light allowed us, as hunter/gatherers to recognize fellow tribe members or potential unfamiliar humans who might be a threat. Being able to make this distinction helped human tribes survive and keep their tribe secure, thus the trait passed on.

This ability developed as our intelligence and ability to recognize patterns developed. It became more and more sophisticated over time, especially once we started doing art. We could draw a rough shape on a cave wall and recognize an animal or a hunter. The shape was "good enough" to fit the brain's rough idea of what said animal or hunter should look like.

So when we see writing like

1N73LL1G3NC3 15 7H3 4B1L17Y 70 4D4P7 70 CH4NG3.

Our brains know to expect letters and therefore it looks at the numbers and picks the letter whose abstract shape most resembles the number that's in it's place, swaps them, and then forms the words


It can do this because 1 is close enough to I. 7 is close enough to T. 0 is close enough to O and so on and so forth.

So thank your hunter-gatherer ancestors for this ability. They gave us the foundations for 1337speak, impressionism, and pixels.

Wikipedia on pareidolia: https://en.wikipedia.org/wiki/Pareidolia

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