Writers, style guides, and people who spend a lot of time reading generally agree that one space after a period is highly preferable to two, but there remains a small group of people who refuse to let go of this convention left over from the typewriter era. Now, two-space devotees have a scientific study on their side. As The Verge reports, a new paper from Skidmore College psychologists suggests that adding two spaces after each period makes text easier to read.
For the study, researchers gathered 60 college students and had them write out a paragraph to determine if they were one-spacers or two-spacers. Next, they asked them to read a sample text while wearing eye-tracking devices. They found that subjects who read the paragraphs styled with two spaces spent less time focusing on the punctuation at the end of each sentence (likely because the extra space made it clearer where the sentence stopped). Students who used two spaces in their own writing read faster when given the two-spaced text.
But don't expect the new findings to shake up style standards any time soon. The study authors admit that while reading text with just one space after each sentence leads to more time spent scanning for periods, the effects are minimal. People in the one-space camp read the paragraphs just as fast regardless of how the text was styled, and the difference in spacing didn't impact reading comprehension in either group. The researchers also used a monospaced font for the study, which may be good for an experiment that requires consistency, but isn't exactly representative of the fonts readers encounter in everyday life.
The question of spacing is as old as typesetting itself. The first printers had two space sizes: a regular one for separating words and a slightly larger one—the emspace—for separating sentences. When typewriters hit the scene, the emspace was replaced with two spaces, and this style of writing was standard for decades. A divide emerged with the advent of more advanced typesetting technology around the mid-1900s. It got easier for printing companies to achieve uniform spacing, and adding two spaces after periods, which many people agree looks sloppy and jarring, started to fall out of fashion. But while the typewriter has disappeared from desks, the two-space method has stuck around. This new study suggests it will likely be with us for a bit longer.
[h/t The Verge]