Originally posted by mattskramer
From where do you get the statistic and the reason for it? Please provide me with a link to a web site giving this information or even a reference.
Sure. It's all through The Bell Curve, published in 1994 by Murray and Herrnstein. The Bell Curve, in turn, cites studies dating back to WWI (Shuey's work) up 'til today. You can also find references in Michael Levin's "Why Race Matters," J. Phillippe Rushton's "Race, Evolution and Behavior," and "Race, Genetics and Society," by Glayde Whitney.
More detail, if you are interested:
Why Race Matters: Race Differences and What They Mean, by Michael Levin. "The main scientific evidence of black/white differences in intelligence is black and white performance on standardized intelligence tests. Competent authorities agree that, as measured by the Wechsler Adult Intelligence Scale, the Wechsler Intelligence Scale for Children, the Raven's Progressive Matrices, and similar instruments, the mean IQ of whites exceeds that of American blacks by about one standard deviation." Page 34.
"This difference was first observed during Army recruits during World War I, and has remained fairly constant." Page 34.
"The most throrough survey of the literature through 1966 is Shuey's The Testing of Negro Intelligence (1966), which reports 382 comparative studies involving 80 different tests administered to hundreds of thousands of black and white children, high school and college students, military personnel, civilian adults, deviates, and criminals. The average black score in these studies was a bit below 85 and the average white IQ a bit above 100, with the difference in the means in the various studies ranging from 12 to 18 points." Page 35.
"In other words, 88 percent of blacks -- and by definition 50 percent of whites -- score below the white mean." Page 35.
Race, Evolution & Behavior: A Life History Perspective, by J. Phillipe Rushton. "For example, Mervyn Skuy and his colleagues (2000) found South African secondary students (in South Africa) had IQ equivalents in the 70s range on several tests, including the Wechsler Intelligence Scale for Children-Revised (WISC-R), the Rey Auditory Verbal Learning Test, the Stroop Color Word Test, the Wisconsin Card Sorting Test, the Bender Gestalt Visual Motor Integration Test, the Rey Osterreith Complex Figure Test, the Train Making Test, the Spatial Memory Task, and various Drawing Tasks." Page 15.
For "cultural bias" debunkment, see Why Race Matters. For inheritiability of the above, see The Bell Curve.