Why the difference in income levels?

Claims that IQ at birth determines one's fortunes in life are based on flawed interpretations of statistical data, maintains labor economist Martin Carnoy, a Stanford University professor of education. He argues that, contrary to Richard Herrnstein and Charles Murray's assertions in The Bell Curve, large changes in African-Americans' achievement and income can result, and have resulted, from government action.

"Herrnstein and Murray repeatedly slide between measures of achievement, which can be altered by a different learning environment, and IQ, which they identify as genetically determined and immutable. To support their claims of the relationship between IQ and income, they rely on studies of the relationship between individuals' wages and a mixture of their aptitude and acquired knowledge. All three components - wage structure, aptitude, and acquired knowledge - can be and are affected by government policies, from programs that improve low-income mothers' prenatal care to early education to the level of minimum wages."

Carnoy suggests that reduced poverty in the 1960s and early 1970s - combined with back-to-basics school reform in the 1970s - produced a major increase in the school achievement of low-income children, especially blacks. No single program caused the change, he indicates. Rather, it derived from the attention Americans paid to the...