For instance, if you retained 80% of what you read. you would still have to be able to read twice as fast as everyone else, since you will be re-reading 100% of what you just read, to get that last 20%.
It isn’t only that… speed reading is based upon the questionable idea that the human brain operates much faster than our eyes can take in information. If the eyes were the bottleneck, it would indeed be necessary to make them work faster.
There is also the belief that sub-vocalization is using an inherently slower part of the brain to process the written word.
This is all bunk.
First of all, much of what we read, especially if we intend to learn anything from it at all, must be thought about to be understood. The goal is not to see who can move his eyes over the page the fastest, but rather to process and make sense of the information that is read. That takes time. If it doesn’t, then you’re probably not reading challenging material, and you might want to reconsider your reading program.
Secondly, the many advocates of so-called “visual reading,” wherein sub-vocalization is eliminated and the words are understood “visually,” seem to ignore that much of the nuance of language is understood in it’s aural form. That is, we make sense out of a lot of information by hearing how it sounds. Sounds convey meaning. That is to say nothing of the ability to appreciate turns of phrase, puns, and other linguistic delights which are best appreciated by “hearing” the words. And my last note on this visual style of reading is this: when you read aurally, you still process the visual elements.
So you are engaging more of your brain in the process, engaging more senses, and experiencing the work more fully. The more engaged you are, the more likely you are to understand and to remember.