"Eric McLuhan, author of Electric Language, adding that English, as the language with the greatest flexibility and largest vocabulary, was the only language prepared for this shift.
But McLuhan, who is the son of the legendary communications theorist Marshall McLuhan, says the 15 years of the computing era have had drastic effects on the building blocks of writing.
Attention spans have declined sharply, and with them, sentence length. Twenty years ago, the average sentence length in a novel was 20 words; today it is 12 to 14 words. In mass-market books such as Harlequin Romance novels, the average sentence is only seven or eight words.
The stuff about English having the greatest flexibility and largest vocabulary is not even worth commenting on, but it seems pretty clear that McLuhan is just making up the sentence lengths too. Just in case, I did a quick tally to see how accurate his claims are. I took the top 10 selling books from 1985 and 2005 (from here) and pulled up the words-per-sentence stats from Amazon.com (e.g., here). Where they weren't available, I took a book from the same author published around the same time. Here are the results.
In this small unscientific study, there is a tendency for sentences to be shorter in 2005 but the difference of 1.33 WPS is nothing like the 10 WPS McLuhan is claiming. And when the largest average for a single book from 1985 is 16.8 WPS, it seems highly unlikely that you're going to find an average of 20 WPS for all novels published in that year. Maybe what computers have made us better at is pulling numbers out of a hat as if they were rabbits. Then again, maybe better is the wrong word.