We only use 10% of our brains, right?
In a word: wrong. I have searched in vain for the source of this widely quoted mis-statement about brain function. Humans, like other animals, use their brains to their fullest extent every day, just to go about the daily activities of living. By and large, we are not even aware of how much processing our brains must perform to accomplish seemingly simple tasks, such as finding our way home from work, or planning what to fix for dinner. The ability to almost instantly pick out the face of our child in a gaggle of schoolchildren, or to recognize the pattern of muscle tension in our spouses face that indicates worry, requires processing algorithms far beyond what the most sophisticated of todays computers can do (and remember, a computer operates at a vastly higher speed than our brain does).
As we shall eventually see, it is the nature of the brain to make cognitive processes much more efficient with practice, and consequently to require much less conscious thought. For those things the brain is genetically programmed to do, it learned to do them well early in life, and they now seem effortless. By contrast, many of the things we ask our brains to do in service of our social responsibilities remain difficult throughout life. Attempting to remain alert and attuned constantly to new stimuli (such as the lectures of a college professor) is a very difficult thing to do, because it requires the brain to both attend to new information while simultaneously trying to process and make memories of the stuff that came just before. Daydreaming in class is not a character flaw, it is the brains efforts to try to carry out its original program. Trying to determine patterns in and make sense of new data is another example of a brain-intense thing to do. Those who are asked to do a lot of this in their societal role, such as medical students, have a hard time imagining being able to sustain it for an entire career. In fact, even the complex patterns of patient symptoms which suggest an illness become familiar, require less conscious attention, and so become easy for experienced physicians.
Perhaps this is the grain of truth in the famous 10% saying. If we can direct our conscious attention to new and difficult stimuli for 10% of our entire day, then we are doing quite well indeed. We need that other 90% to come to grips with what we have learned, to process it into more efficient pathways, and make it easier and less effortful to use.
