100 Things You Should Know About People: #19 — It’s a Myth That All Capital Letters Are Inherently Harder to Read

WHAT YOU ARE ABOUT TO READ IN THE NEXT PARAGRAPH IS COMMONLY BELIEVED, BUT NOT TRUE — You read by recognizing the shapes of words and groups of words. Words that are in all capital letters all have the same shape: a rectangle of a certain size. This makes words displayed in all uppercase harder to read than upper and lower case (known as “mixed case”).  Mixed case words are easier to read because they make unique shapes, as demonstrated by the picture below.

The shapes of words

OK, NOW THE TRUE STUFF STARTS — When I started this article the topic was supposed to be why all capital letters are harder to read. Like most people with a usability background or a cognitive psychology background, I can describe the research — just what I wrote in the first paragraph above. I decided to look up and cite the actual research rather than just passing on the general knowledge and belief.

The research doesn’t exist, or “It’s complicated” — Something happened when I went to find the research on the shape of words and how that is related to all capital letters being harder to read. There isn’t research showing that exactly. It’s more complicated, and ultimately, more controversial. In July of 2004 Kevin Larson wrote an article that is posted at the Microsoft website that explains in depth all the research on this topic. I’ve picked out several ideas from that article and am presenting them here. A link to Kevin’s article, plus some of his research citations are at the end of this blog for those of you who want more detail.

It’s parallel letter recognition, not word shape — The old theory on word shapes comes from a psycholinguist named Cattell who came up with that theory in 1886. There was some evidence for it, but more recent research shows that it is letters you are recognizing and anticipating. You don’t recognize words by the shape of the word. You recognize familiar letter sequences. The research strongly suggests that you recognize all the letters in a word at the same time, and then you use the recognition of those letters to recognize the word.

How you read — When you read you have the impression that your eyes are smoothly moving across the page, but that’s not what is happening at all. Your eyes move in quick sharp jumps, with short periods of stillness in between. The quick jumps are called saccades and the fixations are the moments of stillness. Interestingly ,during the saccades you can’t see anything — you are essentially blind. Fortunately these saccades are really fast so you are not blind for long. They are so fast that you don’t even realize you are having them.

Example of fixactions and saccades
Example of fixations and saccades

How much do you read at a time? —  A saccade jumps you about 7-9 letters, but your perceptual span is actually double that. When you are reading your eyes are “looking ahead” using your peripheral vision to see what is coming next. Some interesting eye tracking studies have been done in which the researchers switch out the letters during the saccade. Then they look for the types of errors you make. I won’t go into the detail of this research (references are below if you want to dig more). But the summary is that you read ahead about 15 letters at a time. When you pick up those 15 letters you always pick them up to the right (if you are reading left to right), although now and then your saccade jumps you backwards and you re-read a section of letters.

Here’s the bottom line — That’s probably more than you wanted to know about how you read! Here’s the summary: You read by anticipating the letters that will be in words, and then recognizing those letters. All capital (uppercase) letters are slower for people to read, but only because they aren’t used to them. Mixed case text is only faster to read than uppercase letters because of practice. Most of what you read is mixed case, and so you are used to it. If people practice reading text that is in all capital letters they can get to the point where they are reading that text as fast as they usually read mixed case. This doesn’t mean you should start using uppercase or capital letters for all of your text. People are not used to reading that way, so it will slow them down, and these days it’s perceived as “shouting”. But now you know that uppercase letters are not inherently harder to read. Maybe we can start dislodging that myth?

And, here’s some links and research citations:

Kevin Larson’s article is at: http://www.microsoft.com/typography/ctfonts/wordrecognition.aspx

Adams, M.J. (1979). Models of word recognition. Cognitive Psychology, 11, 133-176.

Bouma, H. (1973). Visual Interference in the Parafoveal Recognition of Initial and Final Letters of Words, Vision Research, 13, 762-782.

Bouwhuis, D. & Bouma, H. (1979). Visual word recognition of three letter words as derived from the recognition of the constituent letters, Perception and Psychophysics, 25, 12-22.

Cattell, J. (1886). The time taken up by cerebral operations. Mind, 11, 277-282, 524-538. Fisher, D.F. (1975). Reading and visual search. Memory and Cognition, 3, 188-196.

Haber, R.N. & Schindler, R.M. (1981). Errors in proofreading: Evidence of syntactic control of letter processing? Journal of Experimental Psychology: Human Perception and Performance, 7, 573-579. Hebb, D.O. (1949). The organization of behavior. New York: Wiley.

McClelland, J.L. & Johnson, J.C. (1977). The role of familiar units in perception of words and nonwords. Perception and Psychophysics, 22, 249-261.

McConkie, G.W. & Rayner, K. (1975). The span of the effective stimulus during a fixation in reading. Perception and Psychophysics, 17, 578-586. Meyer, D.E. &

Paap, K.R., Newsome, S.L., & Noel, R.W. (1984). Word shape’s in poor shape for the race to the lexicon. Journal of Experimental Psychology: Human Perception and Performance, 10, 413-428.

Pollatsek, A. & Rayner, K. (1982). Eye movement control in reading: The role of word boundaries. Journal of Experimental Psychology: Human Perception and Performance, 8, 817-833.

Pollatsek, A., Well, A.D., & Schindler, R.M. (1975). Effects of segmentation and expectancy on matching time for words and nonwords. Journal of Experimental Psychology: Human Perception and Performance, 1, 328-338.

Rayner, K. (1998). Eye movements in reading and information processing: 20 years of research. Psychological Review, 124 (3), 372-422.


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33 Replies to “100 Things You Should Know About People: #19 — It’s a Myth That All Capital Letters Are Inherently Harder to Read”

  1. Hi Susan, nice post. I like this “there was never such a study stuff” i must confess :)
    Though i think it doesn’t matter in this case. As nobody wants to be the one writing text nobody likes to read, uppercase texts won’t become something common. So people won’t get used to read it and uppercase texts will be slower to read, probably forever.
    And is it really true, that people could read uppercase as fast as the mixed in any case? In quite some fonts uppercase writing takes way more space than the mixed case. So i think this would be still “a problem” for the reading speed (as peripheral vision has it’s limits), or am i wrong?

  2. Thanks for writing in Ingo:

    I agree with you — I’m not planning on putting all my text in uppercase! Apparently the research shows that reading speed is not an issue eventually, but since everything will remain mixed case everywhere else, it would be silly to put text in upper case at my website only.

    I do plan to change my behavior around what I say on the topic when I’m teaching or consulting. I think it is important to cite the research correctly, so I plan to stop talking about “we read by recognizing the shapes that words make with mixed case”. (I’ve been talking about that for years!).

  3. Susan,

    I really liked your explanation of how we read, but…

    You post reminds me of an old joke illustrating the difference between mathematicians and engineers. The punch line points out that by jumping half of the distance between himself and and repeating that action, the mathematician will never get to his or her goal, while the engineer will get close enough for functional purposes.

    My point being that while what you are saying is technically true, it’s not inherently faster. But, being a pragmatist, I’d assert that it is true in the real world. By your own admission, ” People are not used to reading that way, so it will slow them down” that’s the definition of being harder to read. I’m not sure what practical information there is to be gained by learning that if we all became adept at reading all caps, there would be no difference in readability based on case.

    Just my thoughts.


  4. Hi Paul,

    Thanks for your comments. You’re right… it might not be all that practical to talk about uppercase letters being as easy to read as mixed case if we all had practice at it, since it is unlikely we are going to have practice at it! However, I am a stickler about citing research correctly. I’m hoping the post will clarify some misconceptions about how the research is discussed.


  5. Uh… I gotta disagree. We *can* recognize words by their shape *as well as* the sequence of letters. I would agree that sequence of letters is likely more dominant than shape, but people can recognize by shape as well.

    Making absolute statements like “You don’t recognize words by the shape of the word. You recognize familiar letter sequences.” is a bit presumptive.

  6. Hi Malsch,

    Thanks for your comment. I’m being strong in my statements to highlight the research. It’s such a well-believed myth about all capital letters and about how we read (I ought to know, I’ve been teaching it that way unquestioning it for 30 years!), that I feel the need to be strong in stating what the research actually show.

  7. @malsch

    It’s true that we can undoubtedly recognize shape, but how much does that help us in the world of words and language?

    I would challenge you to find 10 people who would be able to tell you that the image on the right at the top of Susan’s post is the word shape. It simply has not been established that that shape equals the word shape like the letter sequence b-e-a-t equals the word beat and has a specific meaning. I would argue that we can recognize LETTERS by their shape but that in the context of reading we have to take a step further to combine those “shapes” into words.

    And for the record, the statement “You don’t recognize words by the shape of the word. You recognize familiar letter sequences,” isn’t presumptive, it’s READING!

    Thanks for the interesting posts Susan. It’s great to dive into the weird, wild world that is our brain :)

    – andrew





  9. I’ve recently been studying best practices of writing code and realized that when developers use a mix-cased style, the code becomes difficult to read as the eyes are forced to jump in the middle of reading the code.

    For example, if a developer writes a variable or function as “myFunction” the capitol F will disrupt the flow of reading through the code (causing a fixation). Whereas if a developer sticks to lowercase, “myfunction” or “my_function” the reader maintains an even flow with less fixations.

  10. Susan

    It’s hard to believe I’ve only just discovered your great list of ‘Things you should know about people’. Keep it up!

    I do have a bone to pick with you about the title of this article. In the text, you write, “All capital (uppercase) letters are slower for people to read, but only because they aren’t used to them.” But if someone just read the title of your article, they would think the complete opposite because of the nuanced way you’ve used the word, ‘inherently’.

    It’s true that people read uppercase text more slowly — it’s just that the classic explanation (word shape) is wrong. But I suppose that “It’s a myth that we read by processing word shape” doesn’t have as much impact as a title!

  11. David,

    Thanks for writing in, and I’m glad you found the blog.

    I don’t know that I meant the title to be misleading. I’ll have to think about that. Since I plan to use that same title for a section in my book (100 Things Designers Need To Know About People) that I’m currently writing. Maybe I want to change that section heading.

  12. Susan,

    Thanks for all these great articles.

    I’d add that there’s more to reading than recognising words. Having everything in caps makes it harder to identify the things that single caps would otherwise indicate – like the start of a sentence or a pronoun. Mixed case text conveys more information.

    For example, mixed case makes it clearer that an orphaned lowercase word actually belongs to the line


  13. “All capital (uppercase) letters are slower for people to read, but only because they aren’t used to them.”

    ? … well isn’t that exactly how we came to the premise that small ones are faster?

    (Wouldn’t it be interesting to know if ‘better’ designed character glyphs would make reading faster or improve comprehension?)

    1. Randy — Thanks for commenting. Here is some more info: There are all kinds of complicated theories about why all capital letters are harder to read. For example, because upper and lower case letters make a word have a unique shape and all capital letters means that all words are rectangles. Lots of urban legends like that. My point is that there is not research to back up any of these urban legends.

  14. It’s not a myth. It is common sense. Most people don’t write in all capital letters, therefore it is harder for most people to read. We haven’t been trained for it, therefore it is difficult.

    I can’t believe anyone actually believes that there was something wrong with capital letters that made them hard to read.

    But then again, people say ‘cursive takes longer than print for them, so we should stop teaching it’ and they still don’t understand that: Of course, doing something you don’t know how to do is going to take longer than something you do know how to do.

    So maybe it isn’t that unbelievable that someone did think that. But I think common sense should have won that argument long before someone had to study how our eyes process shapes.

    1. Agree with Jelzmar. I can’t believe it either. The researchers were asking the wrong questions, not that the answers to their questions were wrong.

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  16. Thanks for this excellent post! I run training for museums, historic houses etc on how to write interpretation. I know that upper case is hslower to read so tell delegates never to use it unless for emphasis of a word that should obviously be in caps eg. WOW! or BANG! or my favourite, YIPEE! However, I am very glad to get a bit more scientific background should I get probed about this. Many thanks for your thoroughly enjoyable and useful article.

  17. While the title of the post may be literally true – in practice, it’s wrong and likely to leave the wrong impression.

    As you note, “All capital (uppercase) letters are slower for people to read, but only because they aren’t used to them.”

    So unless you plan to change the behavior and experience of the entire world – then it’s NOT a myth that all caps is harder to read, and should only be used selectively.

    1. Bob, Thanks for commenting. I understand your point of view, but I’m sticking by the title! It gets people reading and thinking about the concepts… and I did say “inherently”!

  18. The only conclusion I can draw from Kevin Larson’s article is that the proofreading would have been better had the entire article been written in upper case.

  19. Susan,

    I enjoyed your blog. But is there any research related to the following?

    Upper case letters are more difficult to read because they are less legible than lower case letters. The letters in the alphabet represent sound in the spoken language. If you obscure the letter you obscure the sound. If you obscure the sound you diminish the meaning the letter may have to one’s understanding of the words.

    1. Hi Daniel,

      I haven’t heard about any research that connects upper case letters to poorer sound representation and hence poorer understanding.

  20. I liked your article, and I know it was written years ago but I still wanted to make a comment. I’m a director for TV news, and as such I follow the teleprompter as the anchors read it to keep track of where we are in the script. As you may or may not know, teleprompter text is written in all uppercase. I must admit that when I first started reading the teleprompter, it was a bit hard to read. Luckily, though, the teleprompter moves at speaking speed which is slower than reading speed.

    Now, I don’t know the original reasoning behind the uppercase teleprompter text. But I do have a guess. While uppercase is certainly slower to read because we aren’t used to it, I find it is more accurate to read out loud. That is, although it may take longer to recognize the words, this extra time ensures we read (and in the case of the teleprompter, speak) the word correctly.

    So if your focus is on speed, uppercase is not so good. But if your focus is on accuracy, uppercase almost always ensures you read the word correctly.

    1. That’s interesting. I’m going to check that out next time I’m in front of a teleprompter and reading out loud.

  21. Thanks for the post. Several years later, it’s still relevant to me!

    I do want to add one point, very literally from my view. This really is just my personal experience – certainly not studied :)

    I have trouble focusing my eyes. Frequently, I will use the shape of a word to distinguish the actual word. I agree that it’s parallel letter recognition, but with my vision as it is, I seek out specific letters which help me identify a word. Most commonly, these are b,d,f,i,l,p,t,w, and y. Combined with the length of the word and its context, I can usually “read” the word.

    When using all caps, I have a much harder time finding these guide letters. Many things I read in all caps (depends on font choice as well) are difficult to figure out for a couple reasons.

    First, everything is closer to the same size! It’s like picking a criminal from a lineup. If I know the criminal was only 5′ tall, I could easily rule out potential criminals that were over 6′.

    Second, the letters start looking like different variations of 0 and 1 to me. When I get to the actual #1, I usually will mistake it for an I or an L. It can get very frustrating when all-caps and numbers are used together!

    Third, the extra time I need to use to get me to read with these limitations usually puts me out of commission. If in a presentation, I am no longer listening to the presenter. I’m no longer listening for context. Instead, I’m usually squinting soooo hard to see, it looks like I’m ready to kill the presenter.

    I think you are spot-on about practice making it easier to read all-caps. I can’t confirm or deny it, but I do think that if I took more time, I could find patterns in all-capped letters… BUT I WON’T!!!


    If you know of any newer studies which have come out to support why we should not use all caps, please let me know! I am looking for that, because our corporate culture is making me go blind (kidding) and I need ammunition.

  22. If all caps are not harder to read, why didn’t you publish this article in all caps? Put your theory to the test. Let’s see an all caps version. It’s just as easy to read, right?


  23. Thank you for the interesting article. However, I think your conclusion assumes too much, especially since the article asks readers to question their assumptions about “word shapes”.

    “All capital (uppercase) letters are slower for people to read, but only because they aren’t used to them.”

    The idea that familiarity and practice should impact readability seems like sound common sense, but there may be more to it.

    I wonder if “word shape” and “parallel letter recognition” may be related in some way. If we learn to read words by simultaneously recognizing all of the letters contained within, then the question becomes “can we simultaneously recognize a group of lowercase letters as being a word faster than with CAPS?”

    Since we are reading all letters in a word at once, it would seem important that they have enough contrast between them to become immediately distinguishable from one another.

    Capitals are the same height and usually geometric in shape which make them more legible, individually, since the letter forms are simple and plain. With lowercase, certain letters have ascenders, descenders, or tittles (dot over i and j) which all help the eye differentiate between the individual letters in a word. This complexity helps lowercase words become more readable when strung together in sentences and paragraphs.

    I don’t think that we simply see word shapes as rectangles, but rather complex, unique shapes that we do not need to have seen before to recognize. This is because each word shape is constructed by building blocks (letters) that we already know.

    The psycholinguist from 1886 may have been off the mark, but perhaps not by much. After all, we recognize something as a “whole” by simultaneously recognizing all of its parts. We recognize the shape of a triangle by recognizing the shape of its three sides and their relationship to one another simultaneously.

  24. The title of the article is what’s wrong, not that it isn’t interesting or that it isn’t even true. Who cares if upper case letter are not inherently harder to read – they are harder to learn to read when 1. we haven’t been taught to read all upper case, 2. there are other reasons for using mixed case, such as sentences, etc., 3. persons with reading disabilities, vision disabilities, and technology considerations (text to speech) were not included in many (all?) of the studies, so the conclusions are incomplete at best and faulty at least. And why this even make the 100 things I need to know about people is a. too many for me, b. not even in my top 20, c. no studies have been published that it should even be included in the top 50, let alone top 20 things about “people”. . .

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