A typo more mysterious that most

I came across the following passage in a book I was reading this morning:

typo in 'Does God Play Dice - The New Mathematics of Chaos'

Did you notice the typo? (And in the title?) Typing that for than is a very common slip. It appears in all sorts of prose, edited and unedited. It appears occasionally in my own writing before I fix it. If you Google ‘bigger that’, ‘more common that’, etc., and ignore the false positives, you’ll get a hint of the extent of this mistake. Anecdotal evidence further suggests its prevalence.

For such a widespread and apparently simple typo, its cause is rather mysterious. It’s not like typing my name as Stab or Stabn, which I often do, and which is a simple misstroke resulting from the adjacency of B and N on a QWERTY keyboard and the mechanical imprecision of my typing. T and N are not adjacent, and that-for-than is not an error of omission, duplication, transposition, or repetition. Nor do that and than overlap in meaning. So whence this ubiquitous typo?

Last year on Language Log, Mark Liberman wrote an interesting post about typing slips, with a link to a detailed study (PDF, 1.6 MB) that analysed skilled typing and categorised typos. Its authors describe as ‘capture errors’ those that occur ‘when one intends to type one sequence, but gets “captured” by another that has a similar beginning’. Along the same lines, Arnold Zwicky has written about ‘completion errors.’ Typing that instead of than seems to fall into this category, but there are several kinds of capture/completion error, each with its own idiosyncratic and often elusive causes.

Contagion and imitation might be responsible for some wrong thats, especially among learners and non-native speakers. The words’ strong typographical resemblance to each other is an obvious factor in their confusion. Only in the last letter do they differ; even there, /t/ and /n/ are both alveolar consonants, so they sound similar to our mind’s ear. (If you’re unconvinced, say them slowly and notice where your tongue goes.) Both that and than often follow adjectives, which may be another reason the slip slips by: on a cursory glance, this particular wrong word just isn’t conspicuously wrong enough. Since that is a legitimate word – unlike, say, *tham or *thaj – it is more likely to go unnoticed during proofreading.

That-for-than substitution could also have something to do with muscle memory and the commonness of the word that. When fingers type T, H, A in rapid succession, and ‘expect’ to finish the word with one more letter, some kind of functional groove seems to be momentarily adopted, a pattern-recognition program that bypasses Central Cognitive Control and completes the desired word automatically and sometimes erroneously. A lapse is all the more likely because the left forefinger (usually) is already hovering over T and requires little encouragement, less effort, and no lateral shift to drop once more. It does not question the manoeuvre, because it is just a finger, and perhaps a tired one at that.


The comments on Liberman’s post make for an intriguing read. One contributor writes: ‘I think it’s similar to certain errors I make while playing the piano: my fingers are used to one sequence of movements rather than another, so that’s what comes out when I’m not paying attention.’ I’ve noticed this too. It also seems more likely when I’m tired, or still learning a piece. One hand might take a wrong turn, and if this happens again, it becomes even more likely. Likewise with all sorts of repetitive behaviour, including certain typos, e.g. Stab. The phenomenon harks back to what is sometimes called Hebbian learning, after the great Canadian psychologist Donal O. Hebb, and which is often phrased as ‘neurons that fire together wire together’ – even if the ‘wrong’ combination is firing and wiring.)

While I’m on a binge of jargon, parapraxis is a fancy word for a blunder, what is commonly called a ‘Freudian slip’, or as the OED puts it, ‘the faulty performance of an intended action, esp. (psychology) as indicative of a subconscious motive or attitude.’ Leaving aside Freud’s probable* over-interpretation, and focusing on our neurological fallibility: our minds play tricks on us all the time – they positively excel at it – often for our own good. But mistakes, when caught, allow us a useful glimpse of the strange machinery within. There is much to be learned from analysing such stumbles, though the that-for-than substitution is a very modest example.

Update: Lots more examples of that for than in my follow-up post, ‘Even stealthier that I thought‘.


* Originally typed as probably!

[image source]

37 Responses to A typo more mysterious that most

  1. Tyler Hunt says:

    My fingers have such muscle memory for -tion words that I nigh cannot type the word “ratio” without first typing “ration.”

    • sringland says:

      I see this all the time in the accounting classes I am taking. I do it and so do many others, which made me wonder why. It must be because of the common keystroke sequence for words ending in -ration.

      • Stan says:

        sringland: I’d imagine so. Even the string -atio- or just -tio may be enough to activate an erroneous completion circuit in muscle memory.

  2. Stan says:

    Tyler: That’s interesting. Does it happen with patio?

    Reading about the different types of typo described by Rumelhart and Norman, I find I commit many if not most of them to varying degrees. Not many word-specific ones become habitual, though; I should probably pay more attention to any that do!

  3. Tyler Hunt says:

    Stan: No, not with patio, but maybe there’s something more to it. Maybe it’s because of words like iteration and preparation.

  4. Stan says:

    Tyler: There are probably several factors at play. I haven’t looked systematically at -ation suffixes — there are quite a few of them — but I would guess that -ration is substantially more common than -pation. This may contribute to the tendency to over-complete ratio but not patio. More speculatively, another factor could be the lack of a word *pation. Do you hear yourself pronouncing it (or hearing it internally) as “ration” or as “-ration”, if either?

  5. Tyler Hunt says:

    Stan: No, I don’t recall ever hearing it internally, but in typing this response, I came across another: I typed heading for hearing, heading being a word that I use with much greater frequency.

  6. Tim says:

    I think most, if not all, writers — or at least, people who type on a frequent basis — find themselves typing words they don’t intend, or even want, to type. Autofilling seems to be an issue where our hands move faster that our brain (I had to do it). >.<

    This is where proofreading plays an important role. I always read over what I've written, always before submitting it, and in the case of having permission to edit, I will also read it in its final context and then go back and alter any mistakes (and sometimes the wording, as a second reading oftentimes highlights poorly worded phrases or areas where the text could be improved upon).

    At this moment, I can't think of any common autofilling typos that I am prone to fall prey to, but I know that they exist, and they will leap upon me unexpectedly, like a DVORAK keyboard lurking in the shadows.

  7. Claudia says:

    Something that I see, very often, on blogs, is a repetitive teh for “the”. It really annoys me.

    I always reread everything I type before posting it.I also use the dictionary for any word I doubt. A typo mistake could be simply my ignorance of the proper spelling, and my confidence that I have it right. An example: romantiscim. Always thought it was fine till you corrected it. I’m so grateful. I would guess that, since the beginning of my English life, I probably made that mistake for all words ending with ism.

    Ah! well, if not an editor, God will forgive me. The German poet, Henrich Heine, said that it was his job to forgive people. (If you wish, see my comment on Omnium-“Fundamental evil…”:Oct 18,09.)

    Love your illustration!

  8. Stan says:

    ‘where our hands move faster that our brain’

    I almost missed it, Tim! The importance of proofreading is unquestionable, and a good eye for typos is part of an editor’s stock in trade; shop talk aside, their origins intrigue me, especially when obscure. I like a good mystery.

    Have you used a DVORAK keyboard? I never have, though I wouldn’t mind trying some non-QWERTY-style layouts. But repetitive strain injury — now that’s scary.

    Claudia: Teh is an unusual case. Although it is often a genuine mistake, in online discussions it is frequently intentional, and virtually standard in some niches. The irregular spelling has attained a certain informal legitimacy, and can carry various humorous and ironic connotations depending on the context. The Wikipedia page is quite helpful, and links to what seems to be an interesting thesis (PDF, 1.2 MB) on online language: “Is there a translator in teh house?” Teh is discussed particularly on pp. 34-35.

    Thank you for mentioning Heine. Last night, coincidentally, I was reading a poem he wrote with the following lines:

    Frau Unglück hat im Gegenteile
    Dich liebefest ans Herz gedrückt;
    Sie sagt, sie habe keine Eile,
    Setzt sich zu dir ans Bett und strickt.

    Prose translation by Leonard Forster, in the Penguin Book of German Verse:

    Mrs Misfortune, on the other hand, soon takes you to her heart with firm affection. She says she is in no hurry, and sits and does her knitting by your bed.

    Presumably Heine had grander objects than typos in mind when he wrote his poem — the previous verse is about the fleeting nature of fortune (hence “im Gegenteile”). But it was too apt and timely a reference to ignore. If I have cheapened his poem, I can only hope he forgives me.

  9. Fiona says:

    Interestingly, teh/the is one of my own most frequent mistypes. But what I really want to know Stan, is what on earth was the book you were reading?

  10. Stan says:

    Fiona: I suspect that teh happens occasionally to almost everyone who types in English!

    The typo is from an old book on chaos theory: Ian Stewart’s Does God Play Dice? The New Mathematics of Chaos. The inclusion of ‘God’ in the title is a little misleading; likewise in Fearful Symmetry: Is God a Geometer?, a book about symmetry-breaking in nature which Stewart co-wrote with Martin Golubitsky. Both books are generously (and mercifully) stocked with images!

  11. Kelly says:

    Does anyone think that there is more to the typo than just muscle memory and more commonly used words? I’m talking more Freudian typos. Has anyone done this perhaps?…

    When I am typing and get distracted, then quickly resume typing before my brain gets back on task, I sometimes start typing something completely out of context like “hungry” which I was not thinking about but probably around lunch time.

  12. Stan says:

    Kelly: Yes, this happens to me too. A conversation, a song, or a side-tracked train of thought can interfere with my typing and generate a typo, sometimes an entire phrase that elbows its way into the material. It happens subconsciously, like when my thoughts wander while I’m reading, but I don’t notice right away.

    The above post is just a brief examination of a particular typo and some related matters.

  13. An infuriatingly common typo my fingers make is ‘ediotr’ for ‘editor,’ which I am and which makes me feel like an idiot. It happens often enough that I thought I should just begin labeling myself an ediot.

  14. Stan says:

    Beth: That’s a funny one. I don’t recall committing that particular typo, but I make equivalent ones regularly enough — what Rumelhart and Norman call “cross-hand transpositions”. A quick online search indicates how common *ediotr is, usually but not always in informal contexts. The letter sequence -iotr is not very common in English, but Piotr is the Polish equivalent of Peter. But that’s probably neither here nor there.

  15. ZombieZoidberg says:

    On a similar note, one of my recent pet hates is people that type ‘of’ instead of ‘have’; as in ‘he should of gone to Specsavers’ (not an actual ad!). That’s probably more stupidity than typo, though.

  16. Stan says:

    ZZ: I would attribute it to a lack of reading, by which I mean books and other edited publications. It shows the influence of speech on spelling. Presumably the misspelling arose because the abbreviated -‘ve form sounds so much like unstressed of.

  17. herself says:

    I’ve enjoyed reading this discussion and found myself nodding in agreement with Kelly’s post,having just been checked by a colleague for offering her a “life” instead of a “lift” from one destination to another – as in “I an happy to give you a life”. In another context, I don’t do predictive texting and sometimes when I hit the predictive key by mistake I have been bewildered by such gems as “hopdeed” offered to me for “hopefully” and “wiggling” for “wishing”. I’m too old to try to make sense of it

  18. Stan says:

    Herself: Thanks for joining in the discussion! I hope your colleague didn’t take the mistake personally. Predictive text I find mostly helpful, sometimes aggravating, and occasionally very funny, though I tend to switch between predictive and ordinary mode several times per text.

    Hopdeed is a very good word for a non-word. Googling for it and filtering out hip (to omit hip-hop-related results) gives only two pages, one of which is a book called The Life of Napoleon Buonaparte, Emperor of the French. It has been poorly reconstructed: “More than a hopdeed tfaoosand men were employed at one tim* in tbeir efforts to sujnngete this devoted province. But this* could not last ft* ever; …”

  19. […] October I wrote about this mysterious that-for-than typo, investigating among other things its typographic, mechanical, and phonetic aspects. Since then […]

  20. Jen Phillips says:

    I do this when writing by hand as well as typing. I used to work for a company called Jennings and it took conscious effort not to follow Jenni- with -fer. I always put it down to my name being such a familiar pattern I’d follow it all the way if I wasn’t paying attention.

    I can empathise with the pianist, too. I do the same thing on the violin. Interestingly, I don’t on the guitar, possibly because I’ve not been playing long so the patterns aren’t second nature yet.

  21. Stan says:

    That definitely sounds like a capture error, Jen. We increase efficiency by automatising routine acts, but what we gain in time and attention we can occasionally lose through inaccuracy.

  22. I haven’t read all the comments closely, so the point may already have been raised, but is the error in one direction only? Is there no significant incidence of ‘than’ for ‘that’, and if not what does it tell us?

  23. Stan says:

    Barrie: It’s very unlikely to be in one direction only, but it seems (based only on casual observation) almost always to be a case of than becoming that. I mention one possible factor just above the chimp photo, but I’m sure there’s more to it than mere mechanical laziness. Frequency of use probably plays a significant role. The British National Corpus has 1,119,443 thats and 144,654 thans, which gives a rough idea of their respective incidences.

  24. Yes, I like the keyboard explanation.

  25. Confused says:

    I’ve found the that-for-than substitution so prevalent in writing, I thought that maybe I had missed a particular English lesson back at school and that it was to make completely legitimate sense. Even when I Googled the phenomenon, I found edited articles with the mistake, further fueling my confusion.

    So I’ve been trying to find the answer to this question for a while now and I managed to stumble across your discussion. It’s all much clearer now that it is indeed a mistake, but who knows, maybe with its prevalence it will be incorporated as valid written English someday? I appreciate the article, Stan. This thing has been bugging me for a while!

  26. Stan says:

    Confused: You’re most welcome. I’ve seen the error in several other books since, as well as in edited writing online. Maybe it should receive special mention in proofreading courses! Despite its frequency, though, I don’t expect it ever to become a legitimate usage.

  27. […] minor and has to do with the typo in the tweet (more important that instead of …than). It’s a remarkably sneaky typo, which I’ve noticed repeatedly in edited publications. Writers, proofreaders, and style guide […]

  28. David Morris says:

    At first I *didn’t* spot the typo in the heading or in the image of the book. If casual typing leads to the production of typos, then casual reading may lead to the ignoring of them. (BTW, I initially typed ‘ing’ at the beginning of ‘ignoring’, because ‘ing’ is a far more common sequence, and I had already finished *thinking* the word and had the ‘ing’ echoing in my mind before I started typing.)

    • Stan says:

      It’s definitely an easy typo to miss. But I’m surprised by how many proofreaders and editors miss it (see my growing collection of examples here), since their readings should be anything but casual.

  29. John Cowan says:

    I used to type return as reutnr for years, although recently it’s gotten a lot better, who knows why.

  30. kirkjerk says:

    Sorry to be commenting on such an old post, but this article has high Google juice for “phonetic typos”.

    My main mix up has weird phonetic swaps between existing words – especially ones that start with “m” with “b”, in particular “by” for “my” and “me” for “be” (it seems an oddly bidirectional switch, either) I heard somewhere that “m” and “b” has similar “mouth feel”, so I probably have some neurons wired together from way back, along with evidence my typing systems piggybacks on my speaking system.

    Other ones are “numbers and the sounds they have”, so I read a poster for “5th Element” that said “IT MU5T BE FOUND” as “muft” – ignoring the visual pun for the acoustic part. And my first name is Kirk, and I have something I wrote as a toddler: KI4K”

    So it’s infrequent enough to be a mild annoyance, though I’m trying to figure out if it’s getting worse with age.

    • Stan Carey says:

      Comments on old posts are always welcome, and these are interesting swaps. ‘M’ and ‘b’ do have similar mouthfeel, being close to one another phonetically. Both are voiced bilabial consonants, /b/ a stop or plosive, /m/ a nasal, so they’re adjacent in the IPA chart. How exactly they get mixed up in your case, I don’t know, but it makes a certain sense.

      I wonder how common the numbers ones are – I’m sure you’re not the only person who instinctively reads MU5T as ‘muft’, etc., though it’s not something that happens to me.

      • kirkjerk says:

        Thanks for your feedback. My number/predominant sound mixup makes clever “‘1337”-speak “pa55w0rd5” extra painful and slow for me.

        For the M/B swap: I’m a very fast reader, which is another way of saying “I skim a lot” (but with reasonable comprehension, getting the gist right almost always) So my theory is that the subprocesses that do the actual reading and reporting do a LOT of crosswiring with the inner/phonetic voice, and typing is similar but in reverse.

        Always fun to analyze this stuff with interested people!

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: