IQ and other test measures of intellectual ability can be compared by using standardized scores, z- scores, measured in units of standard deviation called sigma. IQ is standardized at a mean of 100 and a standard deviation of 15 or 16. Most IQ tests do not measure scores higher than five sigmas. See the citations in General Books. High intelligence in itself does not guarantee immunity from what may be called stupidity.
Stupidity is a socially taboo topic of discussion and has two different meanings.
In its other meaning, stupidity is not the opposite of intelligence but rather a complementary human attribute. The phenomenon of stupidity is analyzed in two books entitled Understanding Stupidity and The Story of Stupidity , both by James F. Welles. He presents stupidity as a schematically generated, self-deceptive breakdown of the feedback mechanism between behavior and the environment. See the citation in Special Books. And How to Correct Them by Gary Belsky and Thomas Gilovich.