Tuesday, September 02, 2008

The Fallacy of Hereditarian Racial IQ Gap Theory

The latest death toll figures from Hurricane Katrina can be seen on this website here. The famous Russian neo-Nazi video is on this blog here.

Updated September 2. I am republishing this piece which I published earlier. I am including some links and some more data making the case for a 6-10 Flynn Effect gain for US NE Asians from the 1970's to today. They went from about 97.5 IQ to 103.5 IQ (or 100.5 IQ to 106.5 IQ renormed) over 30 years, meeting and then surpassing US Whites, a gain of approximately 6 full points, purely by the environment.

In the comments section, Alan Weiss, a very smart guy, says it is either intellectually lazy or racist to assume that the B-W IQ gap, now at 13.5 points, not 15 points, as is frequently reported, is genetic. I don't agree that it's automatically racist or lazy to assume that the B-W gap is genetic. The hereditarians have done some excellent work in proving their case.

I guess my argument is that the hereditarian case is not necessarily relevant. Saying that "the gap is genetic" doesn't really mean much.

The hereditarians say that 70% of the B-W IQ gap is genetic?

Ok, look.

James Flynn points out that in the 1940's in the US, the IQ gap between NE Asians and Whites in the US was 3.5 points. The scores were US White = 100, US NE Asian = 97.5. Now, the hereditarians say that 70% of that racial gap is genetic, and it's insurmountable. US NE Asians could never come within 1.5 pts of US Whites, no matter what happened in their environment.

But look what happened.

In the next generation, they not only met Whites, but they surpassed them. They gained anywhere from 5.5 to 6.5 IQ points on Whites. Now, with renorming, Whites are at 103 and US NE Asians are at 106. So an "insurmountable" gap that was "70% genetic" was not only surmounted, but it was actually surpassed.

Flynn says that US Chinese had an IQ no greater than Whites in 1949, (actually their IQ was 97.5) yet got better jobs due to extra-IQ factors such as stronger work ethic and higher motivation. They used these new jobs to provide a better environment for their kids, which raised their kids IQ's to 109 in children, falling to 103 by adolescence as parental influence wore off.

In his book, Asian Americans, Achievement Beyond IQ (The book is available for browsing online, and you are free to look through it). Flynn notes that the average US NE Asian American IQ may have risen 10 points over 30 years. From 1943-1975, average IQ was ~97.5 for Chinese and Japanese.

Flynn also found that Chinese-Americans in earlier decades were working at occupations that suggested IQ's fully 21 points higher than what their actual IQ's were.

This shows right there that IQ is not destiny, and there are extra-IQ factors that figure in occupational success. Now it is 103 according to Flynn (106 renormed), and others pretty much concur. This chart shows a US Asian IQ of 106 (Reynolds and Chastain, 1987, p.330). With an IQ of 106, it appears that US Asian IQ may have risen fully 6 points relative to other scores in 20-30 years.

Flynn also suggested an Asian IQ (Chinese, Japanese and Korean) of 104 in the last few years. With renorming, that should be 107. With renorming, all scores point to a US Asian IQ of 106-107.

There is support for Flynn's data from hardcore hereditarians. Richard Lynn reports that Japanese IQ was significantly higher than average IQ in the United States, and that Japanese IQ scores had risen over the past generation (Lynn 1982).

Herrnstein and Murray 1994, Rushton and Jensen 2005 and Lynn 2006 all find that the average IQ scores of East Asians in Asia, North America and Europe are significantly higher than 100. Lynn has US Asian IQ at 106 and rising in this article.

About the Flynn Effect, Flynn notes that our vocabularies and information are no greater than our ancestors, so we can't do any better at reading an adult novel.

The Dickens-Flynn Model shows that all of so-called pure genetic aspects of IQ can actually be explained by the environment.

Smaller families have had an IQ effect that looks like better nutrition - they can provide a better environment for their kids.

Studies have also shown that Asians enjoy studying more than other groups. This may explain their superior performance even relative to IQ.

This is what I mean when I say that when they say that racial gaps are "70% genetic" or whatever, it doesn't necessarily mean all that much. Now the hereditarians have to look at the 3.5 point gain that US NE Asians have over US Whites (US NE Asians = 106.5, US Whites = 103) and say that gap is 70% genetic. Does that make any sense either? Of course not.

Once these "wholly genetic" gaps are not only overcome but even surpassed by purely environmental actions, the whole hereditarian argument gets a bit silly.

References

Flynn, James R. 1991. Asian Americans: Achievement Beyond IQ. Mahwah, NJ: Lawrence Erlbaum Associates.

Herrnstein, RJ and Murray, C. 1994. The Bell Curve: Intelligence and Class Structure in American Life. New York: Free Press

Lynn, R. 1982. IQ In Japan And The United States Shows A Growing Disparity. Nature, 297:222-3.

Lynn, R. 2006. Race Differences in Intelligence: An Evolutionary Analysis. Augusta, GA: Washington Summit Books.

Reynolds, C. R., Chastain R. L., Kaufman, A. S., & McLean, J. E. 1987. Demographic Characteristics And IQ Among Adults: Analysis Of The WAIS-R Standardization Sample As A Function Of The Stratification Variables. Journal of Social Psychology, 25:323-342.

Rushton, J. P. & Jensen, A. R. 2005. Thirty Years Of Research On Black-White Differences In Cognitive Ability. Psychology, Public Policy, and Law.

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