Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Black-White-East Asian IQ differences at least 50% genetic, major law review journal concludes

26.04.2005


A 60-page review of the scientific evidence, some based on state-of-the-art magnetic resonance imaging (MRI) of brain size, has concluded that race differences in average IQ are largely genetic. The lead article in the June 2005 issue of Psychology, Public Policy and Law, a journal of the American Psychological Association, examined 10 categories of research evidence from around the world to contrast "a hereditarian model (50% genetic-50% cultural) and a culture-only model (0% genetic-100% cultural)."



The paper, "Thirty Years of Research on Race Differences in Cognitive Ability," by J. Philippe Rushton of the University of Western Ontario and Arthur R. Jensen of the University of California at Berkeley, appeared with a positive commentary by Linda Gottfredson of the University of Delaware, three critical ones (by Robert Sternberg of Yale University, Richard Nisbett of the University of Michigan, and Lisa Suzuki & Joshua Aronson of New York University), and the authors’ reply.

"Neither the existence nor the size of race differences in IQ are a matter of dispute, only their cause," write the authors. The Black-White difference has been found consistently from the time of the massive World War I Army testing of 90 years ago to a massive study of over 6 million corporate, military, and higher-education test-takers in 2001.


"Race differences show up by 3 years of age, even after matching on maternal education and other variables," said Rushton. "Therefore they cannot be due to poor education since this has not yet begun to exert an effect. That’s why Jensen and I looked at the genetic hypothesis in detail. We examined 10 categories of evidence."

1. The Worldwide Pattern of IQ Scores. East Asians average higher on IQ tests than Whites, both in the U. S. and in Asia, even though IQ tests were developed for use in the Euro-American culture. Around the world, the average IQ for East Asians centers around 106; for Whites, about 100; and for Blacks about 85 in the U.S. and 70 in sub-Saharan Africa.

2. Race Differences are Most Pronounced on Tests that Best Measure the General Intelligence Factor (g). Black-White differences, for example, are larger on the Backward Digit Span test than on the less g loaded Forward Digit Span test.

3. The Gene-Environment Architecture of IQ is the Same in all Races, and Race Differences are Most Pronounced on More Heritable Abilities. Studies of Black, White, and East Asian twins, for example, show the heritability of IQ is 50% or higher in all races.

4. Brain Size Differences. Studies using magnetic resonance imaging (MRI) find a correlation of brain size with IQ of about 0.40. Larger brains contain more neurons and synapses and process information faster. Race differences in brain size are present at birth. By adulthood, East Asians average 1 cubic inch more cranial capacity than Whites who average 5 cubic inches more than Blacks.

5. Trans-Racial Adoption Studies. Race differences in IQ remain following adoption by White middle class parents. East Asians grow to average higher IQs than Whites while Blacks score lower. The Minnesota Trans-Racial Adoption Study followed children to age 17 and found race differences were even greater than at age 7: White children, 106; Mixed-Race children, 99; and Black children, 89.

6. Racial Admixture Studies. Black children with lighter skin, for example, average higher IQ scores. In South Africa, the IQ of the mixed-race "Colored" population averages 85, intermediate to the African 70 and White 100.

7. IQ Scores of Blacks and Whites Regress toward the Averages of Their Race. Parents pass on only some exceptional genes to offspring so parents with very high IQs tend to have more average children. Black and White children with parents of IQ 115 move to different averages--Blacks toward 85 and Whites to 100.

8. Race Differences in Other "Life-History" Traits. East Asians and Blacks consistently fall at two ends of a continuum with Whites intermediate on 60 measures of maturation, personality, reproduction, and social organization. For example, Black children sit, crawl, walk, and put on their clothes earlier than Whites or East Asians.

9. Race Differences and the Out-of-Africa theory of Human Origins. East Asian-White-Black differences fit the theory that modern humans arose in Africa about 100,000 years ago and expanded northward. During prolonged winters there was evolutionary selection for higher IQ created by problems of raising children, gathering and storing food, gaining shelter, and making clothes.

10. Do Culture-Only Theories Explain the Data? Culture-only theories do not explain the highly consistent pattern of race differences in IQ, especially the East Asian data. No interventions such as ending segregation, introducing school busing, or "Head Start" programs have reduced the gaps as culture-only theory would predict.

In their article, Rushton and Jensen also address some of the policy issues that stem from their conclusions. Their main recommendation is that people be treated as individuals, not as members of groups. They emphasized that their paper pertains only to average differences. They also called for the need to accurately inform the public about the true nature of individual and group differences, genetics and evolutionary biology.

Rushton and Jensen are well-known for research on racial differences in intelligence. Jensen hypothesized a genetic basis for Black-White IQ differences in his 1969 Harvard Educational Review article. His later books Bias in Mental Tests (1980) and The g Factor (1998), as well as Rushton’s (1995) Race, Evolution, and Behavior, show that tests are not biased against English speaking minorities and that Black-White-East Asian differences in brain size and IQ belong in an evolutionary framework.

Prof. J. P. Rushton | EurekAlert!
Further information:
http://www.uwo.ca

More articles from Studies and Analyses:

nachricht New study: How does Europe become a leading player for software and IT services?
03.04.2017 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)

nachricht Reusable carbon nanotubes could be the water filter of the future, says RIT study
30.03.2017 | Rochester Institute of Technology

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Scientist invents way to trigger artificial photosynthesis to clean air

26.04.2017 | Materials Sciences

Ammonium nitrogen input increases the synthesis of anticarcinogenic compounds in broccoli

26.04.2017 | Agricultural and Forestry Science

SwRI-led team discovers lull in Mars' giant impact history

26.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>