The role of genetics in the black-white IQ gap has been particularly controversial.

Differing rates of economic growth have also been attributed to numerous factors other than racial IQ gaps such as local availability of resources, climate, and sociopolitical factors.

The rise and fall of the Flynn Effect as a reason to expect a narrowing of the Black-White IQ gap.

Some scientists, however, have concluded sufficient evidence exists to support substantial genetic contribution to explain the black-white IQ gap.

Murray argues that the heritability of IQ increases with age which is reflected in the racial IQ gaps gradually increasing.

Debate between James Flynn and Charles Murray about whether the black/white IQ gap is shrinking or staying the same - November 2006.

In Intelligence and Ethnicity, Sowell argues that IQ gaps are hardly startling or unusual between, or within, ethnic groups.

He says that prosperity helped blacks close the IQ gap.

Regardless of the source of the IQ gap, most educators agree that it must be addressed; they often advocate more equitable funding for education.

The book does not address the question whether the cause of the IQ gap is genetic or environmental, but only whether the tests themselves are valid.