z60\doc\web\2002\10\rushiq.txt Message: 6 Date: Sat, 19 Oct 2002 13:39:16 -0400 From: "j.p. rushton" Subject: Question (and progress in evolution On the range of scores, and the meaning of IQ = 70. On the Raven's Advances, out of a perfect score of 36, the current sample of 192 African engineering students range from 2 to 35 with a mean of 22; the 60 East Indians from 11 to 35 with a mean of 26, and the 75 Whites from 12 to 36 with a mean of 29. An IQ of 70 is about the mental age of an eleven year old. Eleven year olds can do many, many things, including fight wars and work in factories or down mines, especially under supervision. They are most lacking in abstract reasoning and, typically, in higher levels of social responsibility, which may require moral reasoning, another form of abstract reasoning. If an IQ of 70 is "normal" (genetically programmed) for Africans then those with Iqs of 70 should not appear "abnormal" in other respects; if an IQ of 70 is abnormal for a White, then those with Iqs of only 70 will appear odd. We do not think of chimpanzees with IQs of 40 (or whatever) as in any way "retarded." They are perfectly normal -- by their standards. I do not know of any evidence inconsistent with the African population having a mental age ranging from about 7 to 16 years with a mean of around 11, while the White American one ranges from about 11 to 20 years, with a mean of around 15.