“Let’s assume we do, in fact, use only 10% of our brain. If you could unlock the remaining 90%, what would you do with it?” –The Daily Post
The belief that humans only use about 10% of their brain seems to contradict most of the research I have read. However, if somehow proven true, I suspect the remaining 90% would only enhance our current abilities. I know many people suggest that the extra 90% of our brain would unlock new abilities currently thought to be impossible (mind-reading, levitation, etc.) but I think it would have a greater effect on what we do poorly.
I think the extra brain power would further enhance our mental-processing weaknesses. The brain activates small regions at a time in an effort to save energy. Individuals sometimes struggle to activate certain regions of their brain while they can easily activate others. This helps explain why people think differently.
With access to 100% of our brain, I would almost suspect that all people would be able to equally assess situations from a variety of perspectives and we would essentially lose both our individuality and our broad personality types.