Is there no black-white IQ gap in Britain?
"58% of the variance in maths GCSE results was explained by intelligence in 2002, yet by 2010-2013 this halved to 31.4%. By comparison, 73.4% of the variance in SATs in America could be explained by g before the 1994 reforms (Frey and Detterman, 2004). GCSEs are just not a good measure of intelligence anymore."
I believe you should use the g-loading rather than the variance explained by g, as the expected gap would be closer to proportional to g-loading than to variance explained by g? I.e. a g gap of 1 standard deviation would not lead to a test gap of 0.58 and 0.31 standard deviations, but instead closer to 0.76 and 0.56 standard deviations? (Not exactly these numbers because Cohen's d is kind of weird, but approximately.)
"Hereditarian, (Frost, 2021, 2019) has proposed some explanations. His first explanation is that blacks are likely to cheat more."
I fell off my chair when I read that sentence. Did I actually write that? Well, no. I wrote that Nigeria is a low-trust society and that Nigerian students feel it is legitimate to cheat on university exams. It doesn't follow that they are more willing than white Europeans to cheat friends and family members. (I suspect the reverse is true). It's an even greater semantic leap to say that "blacks" in general are likely to cheat more.
"His second argument is that because blacks faced immigration restrictions in coming to the UK, we have a selected sample of especially intelligent blacks."
I considered that argument and rejected it. I did make a second argument, i.e., higher cognitive ability does exist among some African groups, like the Igbo. Why didn't you mention it?
"Nigerian academic achievement may be genuine in some cases. This is particularly so with respect to the Igbo, who have a longstanding record of achievement within and outside school."
Finally, I have never identified myself as a "hereditarian." The term is meaningless and is most often used by people who want to shut down the nature-nurture debate (like "ultra-Darwinian" and "genetic determinist"). Why are you using it? Please don't use me as a sock puppet for views I don't actually hold.
Immigration selects for IQ but also conscientiousness. Blacks care more about GCSE's than the white working class
Rushton's application of R-K selection theory to races would suggest that blacks would mature earlier than whites, so perhaps they would be competitive with whites at 16 years old, but not at 18. This wouldn't explain GSCE result changes over time, but might still explain much of the data.
You're saying that GCSEs have become easier and less g-loaded (and thereby more trainable). And therefore the white-black difference has narrowed over time. So either:
1) White scores have stayed constant while black scores have gone up, OR
2) Scores for everyone have gone up, but scores for blacks have gone up higher than for whites.
Which of those statements is true? I'm guessing that (2) is true since the test is now easier. But how do you explain why White scores are not going up higher than blacks?
In the US, the SAT exams for universities have also gotten easier and less g-loaded. The exam is now quite trainable and East Asians are training the hell out of it. Any comment this chart here?