We are very attached to our convictions of whether, when typing, adding one space or two following punctuation a sentence is correct. Depending on the device you're using right now, you may be able to tell I’m a two-spacer, and that probably tells you something about my age.
People who learned to type on a typewriter were taught to always insert two spaces between sentences. It’s because of the fonts used back then, and the way typewriters spaced letters, and except for journalism, which has always been wedded to one-space precision, most people were taught to double-tap the space bar following punctuation. Many modern computers, beginning with word processors back in the 1990’s, have eliminated the second space, and one space has become the accepted norm.
Did you even know this was a thing?!? KTRH News did an impromptu survey of office professionals and found no one really knows the correct rules, but most people have a firm attachment to their chosen route. Some people are downright defensive. It’ like innies and outies: you’re either one or the other, apparently for life. And we take pride in ownership of our proper principles.
The Complete Manual of Typography (2003) calls for one space, but the manual’s author says questions about the correct number of spaces is the one area he gets grilled about most often, and accepts that it’s still open to debate.
It’s not likely to change anything, but another study on the subject was conducted by researchers at Skidmore College, who applied eye-tracking equipment to subjects and found an almost imperceptible advantage to two spaces for reading comprehension.
Younger people accustomed to a Twitter-world tend to use one space; older people tend to hang on to their two-space learning. If you want to hide your age – go with one space. But if you’re over 40, or a fan of Thomas Jefferson, who didn’t type but who was very liberal in his spacing between sentences when writing the Declaration of Independence, feel free to go with two. For the time being, they are both regarded as correct. Tap-tap.