Re: Civilization is (Probably) Doomed at 38:40
It can’t be stressed enough that Lynn’s estimates are unreliable. Ergo, do not rely on them. (For example, in the Global Bell Curve, pg. 50, Lynn cites De Bertoli and Creswell (2004) as showing a 1.6 to 1.82 SD gap for PISA (2000) reading, math, and science tests for Aborigines and non-Aborigines. He then goes on to say, “The Aborigines and Europeans differ on intelligence by 38 points, equivalent to 2.5 SD. Thus Aborigines performed a bit better on these educational tests than would be expected from their IQs.”) This is based on his deflated SD of 50. (“The standard deviations were approximately 50.”) In reality, the standard deviations were about 100, and the standardized gap was about 0.8 SD.)
Note that this paper was published the same year as Richard Lynn’s Global Bell Curve (in which which Lynn judiciously estimated an Aboriginal IQ of 62).
Leigh and Gong, 2008. Estimating Cognitive Gaps Between Indigenous and Non-Indigenous Australians
Refer to table 1, which summarizes the results of several large studies, results which agree with others that I have pointed to (e.g., Dalton, 2010 and Thomson et al., 2010). The Aboriginal-non Aboriginal gap is 1 SD at most.
It’s worth noting that the authors of this paper are not particularity unrealistic about race:
Not all of the test score gap between Indigenous and non-Indigenous children should be regarded as being causal. On the PPVT (a test of language skills), about two-thirds of the racial test score gap appears to be due to differences in socio-economic factors. On the WAI test (a test of school readiness), about one-third of the racial gap is due to differences in socio-economic factors. From a social policy perspective, this implies that policies to improve incomes and parental education may partly close the Indigenous/non-Indigenous test score gap, but are unlikely to bring Indigenous children’s test scores up to parity with non-Indigenous children.