I do believe that humans have uptapped potential. However, I've recently changed my view on the 10% myth. FYI look at these sites, there is no scientific evidence of the 10% myth. (just a few sites of many)
http://www.snopes2.com/spoons/fracture/10percnt.htm
http://faculty.washington.edu/chudler/tenper.html

What is interesting is how the media has kept this myth alive as you will see on the sites.