Am reading Super Freakonomics tonight after swimming at the “Y”. Consider this:
In 1960, about 40% of female teachers scored in the top quintile of IQ and other aptitude test, with only 8% in the bottom. Twenty years later, fewer than half as many were in the top quintile, while more than twice as many in the bottom.
Between 1967 and 1980, U.S. test scores fell by about 1.25 grade-level equivalents.