(1) Can you add a table listing countries and the source dataset from which the estimates were made?

This could be determined by looking at the supplement, though I suppose it could be placed in the appendix.

(2) Change "not apply to the whole population" to "not apply to all populations" if this is what you mean.

That was not what I meant.

(3) In the paper "To project the IQ of the world at any given point, the average IQ of the world was calculated for each year between 2024 and 2122." So you did not used heritability at all in the calculation of between nation decline? In other word, in the world esitmate, you only reported the selection differential? In the last review, I mentioned that "cross-nation heritability for IQ might be much lower than within-population estimations." I meant that due to different levels of development among nations, IQ differences between countries are more influenced by the environment than individuals within countries. Therefore, lower IQ countries may increase IQ more due to enronment improvements in the future.

No. I used the heritability estimate to convert the selection differential to responses to selection at the individual level, but the between country environmental effects were assumed to be stable. It is possible that some countries will have their average IQs increase, but I think these gains (if they happen) will stop shortly, and will turn into losses quickly, as the genotypic effects start to take over, and the feedback loop kicks into action.

You mentioned, "Classical twin studies and adoption studies that study individuals over the age of 18 find no shared environmental effect on intelligence." It's important to note that the same may not apply to IQ differences among people across nations. For instance, North and South Korea share the same race, but the wealth disparity between them may influence intelligence, with the richer South having potentially smarter individuals due to better nutrition. Higher fertility in the North would not necessarily cause dysgenic fertility for Koreans as a whole. (By the way, my opinion is that the South is set to lose among the Koreas due to within-country dysgenic fertility caused by capitalism.) There remains uncertainty regarding cross-nation heritability, and you should note this.

I'll note it, but the point of mentioning the classical twin studies was to argue that intelligence is a highly heritable trait in general, not that there is no shared environmental effect in all countries; the heritability of intelligence may be lower in developing countries, but the trait will continue to be heritable anyway.

No. I used the heritability estimate to convert the selection differential to responses to selection at the individual level, but the between country environmental effects were assumed to be stable. It is possible that some countries will have their average IQs increase, but I think these gains (if they happen) will stop shortly, and will turn into losses quickly, as the genotypic effects start to take over, and the feedback loop kicks into action.

 

No. I used the heritability estimate to convert the selection differential to responses to selection at the individual level, but the between country environmental effects were assumed to be stable. It is possible that some countries will have their average IQs increase, but I think these gains (if they happen) will stop shortly, and will turn into losses quickly, as the genotypic effects start to take over, and the feedback loop kicks into action.

“between country environmental effects were assumed to be stable”

This is an questionable assumption. While poorer countries may remain less wealthy than rich countries in the future, the gap in their environmental impact is likely to narrow. Therefore, the gap in national IQ could also decrease.  For example, a nation with 80 average IQ could reach 90 points in the future. I'm not proposing that their average IQ will surpass that of rich countries, but rather that the environment could play a significant role in closing the current gap. You may disagree, but a scientific paper should acknowledge this possibility.

Very well.

edit: the acknowledgment is in page 9, phrase "While this is likely to be close enough to the truth for developed countries, this may not be the case for developing countries."

That is the last of the objections I see to the paper. Can this be published?

Replying to Sebastian Jensen

That is the last of the objections I see to the paper. Can this be published?

You did not address my objections. Given the high degree of uncertainty in your assumptions (which you acknowledge), you should provide a series of projections with different assumptions. Otherwise I recommend rejection of this paper.

Replying to Sebastian Jensen

It's news to me that Africa is located in Southeast Asia/Central America, but what do I know?

Please adopt a more collaborative attitude toward the peer review process. The aim, here, is to make you better, not bitter. This experience will make you better prepared for future efforts in the world of journal publication, and I can tell you -- from personal experience -- that reviewers can be very, very tough. Please see this "toughness" in a positive light. It's a chance to see your work as others see it—and to see the faults that you don't see.

Finally, I didn't wish to insult you. I only wished to correct your mistaken impression that I had approved your paper for publication. I'm sorry, but I don't think it is publishable in its present form. It could be improved, but that means making fundamental changes ... and not cosmetic ones.

Replying to Wed 10 Jan 2024 04:50

Replying to Sebastian Jensen

That is the last of the objections I see to the paper. Can this be published?

You did not address my objections. Given the high degree of uncertainty in your assumptions (which you acknowledge), you should provide a series of projections with different assumptions. Otherwise I recommend rejection of this paper.

I did. I provided estimations based on newer data which had the same results, the whole Southeast Asian/Central American objection was bunk, and I provided examples of unrealistically bleak futurs (e.g. 50 million Central American immigrants) to argue that the national IQ of the USA will not drop that much because of immigration.

Could I get the stances of the other reviewers on this paper?

"While priors dictate that mutational load should have an effect on IQ, the effect that it has on genotypic IQ over time cannot be quantified at the moment. Likewise, environmental factors between countries and within countries were assumed not to vary. While this is likely to be close enough to the truth for developed countries, this may not be the case for developing countries."

 

Can you add this after that to make your assumption more explict? If so, I am OK with your paper:

If environmental conditions improve in developing countries, the Flynn effect could lead to increased IQ in those populations. Therefore, their higher fertility rates might not contribute as significantly to the global dysgenic fertility estimated in this paper. However, the heritability of IQ between nations (i.e., the extent to which lower IQ in poorer countries is due to environment or genetics) is unknown. For the sake of modeling, a between-nation heritability of 1 is assumed, making the estimates in the paper more of an upper bound.

My December 10th response seems to have been missed by the author.

I see he added in McClean, but checking the source, it does not give the formula. Please offer a proof of the formula you used, or else cite a source that does prove it. This is important because it's the cornerstone of the paper, and I imagine an unfamiliar reader would like to be able to access a proof of the formula that the paper is based on.

Also, please update your scatter plots to include the r value, n, and the 95% CI of the r value as text in the corner of the graphs themselves. This makes the charts way more readable. Most people don't want to scour the text for these values. I pointed you toward a library that does this easily.

After just these two things I will approve the paper.

Replying to Sebastian Jensen

Congratulations! I approve this paper for publication. A few suggestions:

- replace "correlates at" with "are correlated at" or "have a correlation of"

- replace "put the latter finding in question" with "call the latter finding into question" or "cast doubt on the latter finding"

- replace "between the years of 2023 and 2100" with "from 2023 to 2100"

"large studies in Taiwan and China" - it might be better to use "the People's Republic of China" (Taiwan self-identifies as "China")

- replace "they adjusted for" with "the authors adjusted for"

- replace "even when it is tested" with "even when tested"

- replace "exists when controlling for" with "when controlled for"

Be consistent in use of zero before decimal point.

"Islamic" and "Pew Research" should be capitalized.

- replace "as it was the only test that was available" with "being the only test available"

- replace "one of the parents of the child" with "one of the child's parents"

- write out a number if it's at the start of a sentence ("Thirteen failed")

- replace "Balkan" with "Balkans"

- replace "Nordic" or "Nordics" with "Scandinavian" if that's what you mean. Are Finland and Estonia covered by the term "Nordic"?

- how do you define the "Anglo" region?

The new version has included the graphs, a paragraph explaining why the assumption of cross-national heritability being 1 overestimates declines, and all projections related to immigration were removed.