Why Are You Shouting?

Scroll to the bottom of almost any software licence and you’ll hit a block of capitals. THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND… It goes on for a paragraph, every letter at full height, glaring at you.

There’s a reason for it. In US contract law, a disclaimer of warranties has to be “conspicuous”, and lawyers decided long ago that the safest way to make something conspicuous is to capitalise it. So the one paragraph the law says you must notice is set in the one style that’s hardest to read. Everyone’s eyes slide straight over it. It’s the bit you must see, and the bit nobody reads.

Capitals don’t give you emphasis. They give you volume.

Here’s why. First, we’ve had less practice reading them. Almost everything you’ve read since primary school was mostly lower case, and reading speed is largely familiarity. In the classic legibility studies of the twentieth century, readers working through all-caps text were noticeably slower, in the order of ten per cent. The gap shrinks with practice, which tells you the problem is mostly habit, not biology.

Second, capitals are all the same height. Lower case has variety: ascenders on b, d and h, descenders on g, p and y. Each word has a texture your eye can grip. Set it in capitals and every word becomes a row of identical rectangles.

Third, capitals take up more room, very roughly a third more. So you get text that’s slower to read and looks longer before you’ve even started.

There’s a word origin hiding in all of this. “Upper case” and “lower case” were literal. Printers kept their metal type in two wooden cases, one above the other. Capitals went in the upper case, and the small letters, which they needed far more often, sat in the lower case, closer to hand. The vocabulary of computing still carries that cabinet around.

For a while, capitals were all that some machines could manage. Teletypes and several early home computers worked in upper case only, and the original Apple II couldn’t display lower case without modification. Programmers wrote in capitals because the hardware gave them no choice. When the internet arrived and everyone could finally type in both cases, capitals got a new job. Netiquette guides in the mid-nineties spelled it out: write in mixed case, because upper case looks as if you’re shouting.

That rule has teeth. In 2009 a New Zealand health insurer sacked an employee partly over emails written in capitals, bold and red, which colleagues found confrontational. An employment tribunal later found the dismissal unjustified and awarded her compensation. Still, the case went round the world because everyone recognised the emails.

So when should you use capitals? For a single word, occasionally, when there’s no other way to stress it. For acronyms, because there’s no choice. And for a short heading, perhaps, if the typeface was built for it. Never for a paragraph, a warning or anything you actually need people to read.

If something really matters, make it short, put it first and leave it in normal type. People will read a calm sentence. They skim past one that’s shouting.