Biological determinism

From Mapping Human History: Genes, Race, and Our Common Origins by Steve Olson. Page 61.

A nice summary of some points countering biological determinism. Not complete but well established.

* When IQ tests were developed in the early twentieth century, people from different parts of Europe had different average scores. At that point, heredetarians used these differences to distinguish among Nordics (northern Europeans, roughly speaking), Alpines (eastern and central Europeans), and Mediterraneans (southern Europeans). Today the descendants of these immigrants score equally well on IQ tests. Yet the same arguments are now applied, through a sort of bracket creep, to African, European and Asian Americans.

* If genetics were the cause of IQ differences, then African Americans who have higher proportions of European genes should score higher on IQ tests than those with fewer European ancestors, but no such effect has been found. The critical difference is not whether a person is genetically African American; it is whether a person has been treated as an African American.

* Throughout the twentieth century, IQ scores have been going up for all groups, according to a variety of tests conducted in many different countries. These rises have occurred much too rapidly to be the product of genetic changes. They must result from better diets, better health care , and better education.

* Many studies show that children who receive good prenatal care and early childhood education on average score higher on IQ tests than children who do not. Since proportionally more African Americans than European Americans live in poverty in the United States, their scores on IQ tests tend to be lower.

* When researchers tracked down the children born to German mothers and U.S. soldiers during the Allied occupation of Germany in World War II, they found no difference in the IQ scores of children with African-American versus European-American fathers.

* Minorities in many countries score lower on IQ tests than do the majorities, regardless of their ancestry. An example is the Buraku of Japan, a minority that is severely discriminated against in housing, education, and employment. Their children typically score ten to fifteen points below other Japanese children on IQ tests. Yet when the Buraku immigrate to other countries, the IQ gap between them and other Japanese gradually vanishes.

I would add the phenomenon of reversion to mean among emigrant children. High IQ immigrants (doctors, engineers, etc.) come to the US and their children typically score higher than the native population. By the third generation though, without ethnic mixing, the grandchildren of emigrants typically have IQs reflective of the local population.