New MQ paper

Kirkegaard, E. O. W. & Fuerst, J. (2016). Inequality in the United States: Ethnicity, Racial Admixture and Environmental Causes. Mankind Quarterly 56(4).

Previously, we looked at the association between overall state-level biogeographic ancestry (BGA) and overall state-level outcomes. It was found that European BGA relative to African and Amerindian BGA was associated with better outcomes. In this paper, the analysis is extended by looking at the state-level ancestry-outcome associations individually for black and Hispanic self-identified race-ethnicity (SIRE) groups. General socioeconomic factor (S) scores were calculated for US states by SIRE groups based on three indicators. The S factor loadings were generally stable across subgroup analyses and the factor scores were stable across factor analytic extraction methods (for the latter, almost all r’s ≈ 1). For Whites, Blacks and Hispanics, there were strong correlations between cognitive ability scores and S factor scores across states (r = .55 to .78; N = 28-50). This pattern also held when all data were analyzed together (r = .86, N = 115). Furthermore, the size of the Hispanic-White and Black-White S and cognitive ability gaps strongly correlated across states (r = .62 to .69; N = 36-37). Lastly, parasite prevalence did not plausibly explain SIRE gaps in cognitive ability because gaps were smaller in more parasite-rich states (combined analysis r = -.17, N = 91). We found that climatic and geospatial variables did not correlate strongly with cognitive ability and S scores when scores were decomposed by SIRE group, but did so at the total state level, even after statistically controlling for SIRE composition.

Top Ten Human Varieties Posts

In the more than three years of its existence, about 110 posts have been published on this blog. While blogging has unfortunately been light in recent times around here, the upside of the data- and analysis-heavy format of our posts is that they rarely lose their relevance with time, making the perusal of our old posts well worth the time.

To help readers search through our archives, below is a list of what I consider to be some of the best content we’ve published. They’re not necessarily our most popular posts, but I think they offer a good dive into human biodiversity, in particular our perennial favorite topic of IQ differences between groups. The list is in the order of original publication. Continue reading

Into the IQ shredder

Wang, M., Fuerst, J., Ren, J. (2016). Evidence of dysgenic fertility in China. Intelligence, 57, 15-24.

From the discussion: “We’ve seen, in Table 4, that urban populations in China exhibited a relatively high dysgenic fertility trend in the 1951–1970 birth cohort. For this same cohort, the trend was much smaller in the rural populations. It suggests that dysgenic selection is related to urbanity. This supports Pan’s (1923) observation that “modern urbanization has had so many dysgenic effects upon the race.”

Philosophical Reflections on On Genetic Interest

I will leave a sum in my last will for my body to be carried to Brazil and to these forests… and this great Coprophanaeus beetle will bury me. They will enter, will bury, will live on my flesh; and in the shape of their children and mine, I will escape death. — Hamilton, 1991

Opening reflections

Through reproduction, living beings obtain immortality. This was the view of the ancients. All beings seek the divine, which is the eternal. For mortals, unending life can only be had through generation. While the individual particularity is doomed, through reproduction the general form can be perpetuated and a type of eternity can yet be grasped. In De Anima, Aristotle expresses the view thusly:

For any living thing … the most natural act is the production of another like itself, an animal producing an animal, a plant a plant, in order that, as far as it nature allows, it may partake in the eternal and divine. That is the goal towards which all things strive, that for the sake of which they do whatsoever their nature renders possible… Since then no living thing is able to partake in what is eternal and divine by uninterrupted continuance for nothing perishable can for ever remain one and the same, it tries to achieve that end in the only way possible to it[.]

In Plato’s Symposium, Diotima accounts for filial love likewise:

For among animals the principle is the same as with us, and mortal nature seeks so far as possible to live forever and be immortal. And this is possible in one way only: by reproduction… And in that way everything mortal is preserved, not, like the divine, by always being the same in every way, but because what is departing and aging leaves behind something new, something such as it had been… So don’t be surprised if everything naturally values its own offspring, because it is for the sake of immortality that everything shows zeal, which is Love.

Genetic Interest

A decade ago, Frank Salter published On Genetic Interests: Family, Ethnicity, and Humanity in an Age of Mass Migration (OGI). The book’s stated purpose was not to account for human behavior, “but rather to offer social and political theory about what individuals should do.” The book attempts to answer a theoretical question: “How would an individual behave in order to be adaptive in the modem world?” — where “adaptive” means maximizing the survival chances of the totality of one’s unique gene frequencies. In line with the book’s title, Salter concerns himself with individual, family, ethnic and species genetic stake. He concludes that a portfolio with a balanced investment in all of these is preferable. He asks, “Which [gene conserving] strategies are best?” And then replies that focusing exclusively on any one level of genetic interest is suboptimal. He concerns himself largely with “ethnic genetic interest” (EGI) for two reasons. First, reigning ideologies neglect it. They end up, as he notes, advancing species genetic interest (e.g., radical Christianity and humanism) and, when not, individual and family interest. And second, mass immigration presently threatens the existence, as coherent biocultural groups, of many ethnic groups.

Salter, both an ethnologist and political scientist in training, notes that he was motivated to write OGI after having discovered, with the help of anthropologist Henry Harpending, that the aggregate kinship shared by members of a typical ethnic or racial group, relative to random members of the species, “was typically 1000 times greater than” he originally anticipated. Prior to writing the book, he had been using van den Berghe’s theory of ethnic nepotism as a heuristic to understand ethnological findings. He wrote the book in light of his findings and the ongoing replacement-level immigration to the West. He felt that the biological impact of that process needed to be analyzed and discussed.
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The Genealogy of Differences in the Americas

The first two of our admixture in the Americas papers have been published at Mankind Quarterly. To note, as I am skeptical of a behavioral genetic model, we advanced a genealogical one with an unspecified mode of inter-generational transmission. Similar models have been adopted in the economic literature (for example: Putterman and Weil, 2010; Spolaore & Wacziarg, 2015). For open access, we uploaded our papers to Research Gate. For the sake of transparency, the 18 supplementary files, the R syntax and the other data files have been made publicly available at Open Science Frame. The six commentaries are locked behind a paywall, but we covered most of the criticisms in our reply paper. If you can get a hold of them, though, they are well worth the reading. The conclusion of the reply paper sums up our general position:

We were pleased with the caliber of the comments. While incisive, none of them have inclined us to alter our conclusion concerning the R~CA-S hypothesis. But what now? First, more data. Specifically, indices of national cognitive ability need to be refined and more regional data needs to be located. In searching for this, it would be helpful to collaborate with researchers who are more familiar with Latin American datasets. Second, it would be worthwhile to further investigate a discriminatory model of individual differences using kinship designs and also to further investigate geographic models of regional differences, for example, using individual-level longitudinal data (to see if relocation to higher absolute latitude or colder regions has a positive effect on individual-level outcomes). Our models, in aggregate, are consistent with the view that contemporaneous cold weather and/or latitude is causally associated with positive outcomes, but an accurate assessment of the magnitude of these effects necessitates taking into account intergenerational factors. More generally, proponents of genealogical, discriminatory and geographic models have a mutual interest in building and making accessible databases that allow for the testing of these competing and probably co-occurring models.

As part of the reply we wrote another paper which focuses on the U.S. and will be published in the summer edition. Three related projects are also in the works.


Fuerst, J., & Kirkegaard, E. O. W. (2016). Admixture in the Americas: Regional and national differences. Mankind Quarterly.

Ibarra, L. (2016). Statistics vs Scientific Explanation. Mankind Quarterly.

Flores-Mendoza, C., & Da Silva, J. A. (2016). Great effort, interesting results, but not everything is what it seems. Caution is required. Mankind Quarterly.

de Baca, T., Figueredo, A. J., & Garcia, R. A. (2016). Commentary on Fuerst and Kirkegaard: Some groups have all the luck, some groups have all the pain, some groups get all the breaks. Mankind Quarterly.

Christainsen, G. (2016). Admixture in the Americas: Social Differences as a Reflection of Human Biodiversity. Mankind Quarterly.

León, F. R. (2016). Race vis-à-vis Latitude: Their Influence on Intelligence, Infectious Diseases, and Income. Mankind Quarterly.

Pesta, B. (2016). Does IQ Cause Race Differences in Well-being? Mankind Quarterly.

Fuerst, J., & Kirkegaard, E. O. W. (2016). The Genealogy of Differences in the Americas. Mankind Quarterly.

Equal Environments Assumption and Sex Differences

In the classic twin study design, identical (MZ) twin pairs are compared to fraternal (DZ) twin pairs so as to estimate the relative contributions of heredity and environment to individual differences. The classic twin design depends on the equal environments assumption (EEA) according to which the shared environment of MZ twins is not more similar than that of DZ twins.

The claim that the EEA is an unrealistic assumption which is routinely violated in reality is perhaps the most common criticism of the classic twin design. Violations of the EEA generally bias estimates of the effect of heredity upwards and those of the environment downwards. For this reason, there have been a number of studies where the assumption has been put to test with research questions such as:

  • Are twin pairs who are misinformed about their actual zygosity as similar as pairs who know their real zygosity?
  • Are twin pairs with objectively more similar environments more similar phenotypically?
  • Are the results of twin studies consistent with the results of other kinds of behavioral genetic designs, such as adoption studies?

This research has indicated that the EEA is generally valid and that even when it’s violated, the effect on parameter estimates is small (Barnes et al., 2014; Felson, 2014).

I think sex differences offer an underappreciated way of further evaluating the EEA. Half of DZ pairs are same-sex (male-male or female-female) and half are opposite-sex (male-female), whereas MZ pairs are, of course, all same-sex. Differences in twin correlations across these sex categories are informative about the EEA because if the shared environment differs by zygosity, you would expect it to differ by sex, too. Continue reading

IQ and Permanent Income: Sizing Up the “IQ Paradox”

In his recent book Hive Mind economist Garett Jones argues that the direct effect of IQ on personal income is modest, and that most of the benefits of higher IQ flow from various spillover effects that make societies more productive, boosting everyone’s income. This, he says, explains the “IQ paradox” whereby IQ differences appear to explain a lot more of the economic differences between nations than within them.

Jones does not say in his book what he thinks the exact effect of IQ on personal income is, but on Twitter he has asserted that “Fans of g would do well to look at the labor lit: 1 IQ point predicts just 0.5% to 1.2% higher wages.” He has also said that, in terms of standardized effect sizes, IQ accounts for only about 10% of variance in personal income (a correlation of ~0.32).

While I don’t doubt Jones’s overall thesis that the effect of IQ on productivity is broader than its effect on personal productivity or income, I think he understates the importance of IQ in explaining income differences between individuals. I analyzed a large American population sample and found a substantially larger effect of IQ on permanent income than previous investigations. It appears that the literature Jones refers to has failed to pay sufficient attention to various measurement issues. Continue reading

The Evolutionary Default Hypothesis and Negative HBD

Jayman (2016) argues:

There is no reason to suspect that human groups that have been separated for tens of thousands of years in vastly different environments would be the same in all their cognitive and behavioral qualities. In fact, a priori we should expect them not to be, since such equivalence after so many generations of separate evolution is nigh impossible.

We can quantify the expectation.

When it comes to quantitative genetic trait differences between populations, the evolutionary default expectation is that differences will be commensurate with the degree of drift (not to be equated with neutral mutations). For diploids, the formula is:


VA G,B is the genetic variance between groups
VA, C is the additive genetic variance in a common ancestral population
2FST is 2 times the fixation index with respect to low mutation rate biallelic polymorphs of the type that underlie the traits in question (see: Edelaar and Björklund, 2011) Continue reading

Measured Proficiency of Ethnic Groups in Canada

Jason Malloy and I have individually collected a large number of papers and research reports from countries around the world detailing ethnic and racial differences. I have sent some of the stuff to Richard Lynn, lost a number of reports due to hard drive failures, and simply haven’t got around for various reasons (time, health, other priorities, etc.) to posting on the remainder. In response to an article by Chanda Chrisala, James Thompson recently suggested that it would be informative to look at ethnic differences in other American countries. As such, I will comment on a few studies from Canada and Brazil. Regarding Canada, there seems to be no published detailed ethnic data for the nation as a whole — though many reports discuss the Aboriginal/overall Canada gap. The country has a number of national longitudinal surveys which most likely contain the relevant variables, but as far as I am aware no has looked into the issue. Nonetheless, since the 1980s the Toronto public schools have published research reports which decompose math and reading pass rates by linguistic, ethnic, and racial background.

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