Population sex differences in IQ at age 11: The Scottish mental survey 1932

In 1932 a test was performed to study the cognitive ability distribution in 11 year old Scottish children, comprising almost everyone born in Scotland in 1921, in order to examine the difference in sexes with respect to their mean levels and variabilities in mental ability test scores. The findings went some distance in explaining the slight excess of men with learning difficulties and a similar level of excess of men achieving first class university degrees.