Distant European populations distinct in facial morphology (no shit?)

Polak mentioned this study in a comment at Dienekes. Nothing too surprising here, but it would be nice to see more efforts of this sort. This is an abstract of a poster from the 2007 AAPA conference (pdf):
Variation in facial features among European populations measured from 3D photographs.

D.K. Liberton1, B. McEvoy2, M. Bauchet1, C.A. Hill1, J.T. Richtsmeier1, T. Frudakis3, M.D. Shriver1.
1Department of Anthropology, Pennsylvania State University, 2Smurfit Institute of Genetics, Trinity College Dublin, 3DNAPrint Genomics, Inc.

The presence of craniofacial variation among continentally described groups has been documented. However, finer-scale phenotypic variation among populations has been more difficult to determine. The purpose of this study is to use three-dimensional images to evaluate if there are significant patterns of facial difference among European populations. Besides determining the extent of regional population differences in facial morphology, this work serves as a foundation for studies involving European genetic stratification and the detection of genes that determine facial features.

The study consists of 180 adult women, aged 18-35, from four geographically discrete European regions: Warsaw, Poland (N=45); Rome, Italy (N=45); Porto, Portugal (N=45); and Dublin, Ireland (N=45). Threedimensional photographs were acquired from faces using the 3dMDface imaging system. Three-dimensional landmark coordinate data were collected from using the 3dMD Patient software and were analyzed using Euclidean Distance Matrix Analysis. Pairwise comparisons between geographic regions were performed to determine patterns of significant differences in facial morphology among the four European populations.

Our results indicate that differences in female facial morphology are symmetrical and that population differences are localized to specific facial regions. This shows that there are statistically significant differences in facial morphology among European populations which can be mapped using coordinate data generated from three-dimensional photographs. Furthermore, these results suggest that morphological differences in facial features may likely be the result of genetic differentiation among European populations.

Supported by grants: Science Foundation of Ireland, Walton Fellowship

Rushton and genital size: one more time

J. Philippe Rushton asserts [1]:
Orientals are the most K, Blacks are the most r, and Whites fall in between. Being more r means: [. . .] more developed primary sexual characteristics (size of penis, vagina, testes, ovaries)
Rushton apparently has many convinced the above assertions are ironclad facts. They are not. Despite Rushton's sometimes selective presentation of evidence, what data exist (on "size of penis, vagina, testes") fail to consistently align with Rushton's Asian < White < African framework.

Penis size

Rushton claims [2]:

We averaged the ethnographic data on erect penis and found the means to approximate:
Orientals, 4 to 5.5 in. in length and 1.25 in. in diameter;
Caucasians, 5.5 to 6 in. in length and 1.5 in. in diameter;
blacks, 6.25 to 8 in. in length and 2 in. in diameter.
The numbers above are apparently lifted directly (or indirectly via Coon's Racial Adaptations) from a book by "A French Army Surgeon" ("Jacobus X" / Jacobus Sutor) published in 1898 (so much for "averages" of "the ethnographic data"; Rushton cites "A French Army Surgeon" as merely an "e.g." of "the ethnographic record", but Rushton's "ethnographic record" is apparently limited to the supposed observations of a single 19th-century individual).

The numbers given for blacks (ranging up to "8 in. in length" for population means) are implausible on their face, and no modern study of blacks comes close to supporting anything but the very low end of that suggested range.

A study of Nigerians (n=115) finds "mean [stretched] penile length was 13.37 cm [5.26 inches] with a median of 13 cm" [3]. Another study, on 320 Nigerians, finds "average [presumably flaccid] length of the penis (81.6 +/- 0.94 mm); circumference of the penis (88.3 +/- 0.02 mm)" [4].

The Kinsey data, which may be less than ideal but which are cited by Rushton both directly and indirectly, suggest any difference in mean penile dimensions between black and white men in America is measurable in fractions of an inch:
White males had an average flaccid penis length of 4.0 inches, whereas the average black male's detumescent member measured 4.3 inches. But when erect, the average white penis was 6.2 inches long, whereas the average black's was 6.3 inches--still longer, but not by much. (Average circumference for whites was 3.7 inches; for blacks, 3.8.)

When Rushton cites WHO condom standards in support of his theory, he is merely indirectly referencing the Kinsey data (plus a sample from Thailand, and one from Australia). WHO did no original research. Their sole "African" sample is the American black sample from Kinsey [7].

[Update: Rushton claims the WHO specify three condom sizes [1]:
The World Health Organization Guidelines specify a 49-mm-width condom for Asia, a 52-mm-width for North America and Europe, and a 53-mm-width for Africa.
I'd taken Rushton at his word here and had not bothered to check his WHO claim beyond determining that WHO did no original research on the subject (as stated above). In reality, it's clear from the guidelines that WHO specify exactly two widths [7]:
WHO specifies a width of 49 mm or 53 mm with a tolerance of ±2 for individual condoms and ±1 for the average of the lot.
The WHO don't make distinctions among Europe, Africa, and Asia, but between Asia and everyone else [7]:
Condoms are made in various widths. Based on studies in Australia, Thailand and the USA, and the experience of major agencies, the wider condoms (flat width 52-55 mm) will be preferred in Australia, Africa, Europe, Latin America, the Middle East and North America, and the narrower condoms (47-51 mm) will be preferred in several Asian countries (see Appendix III). Other widths are also made for small specialized markets.
Note: the ranges encompass tolerances in the specification; only two distinct widths are specified.]

Testes size

Rushton reviews most of the evidence of which I'm aware in his 1987 paper [2]:
Measurements taken from living subjects as well as those at autopsy, show the size of testes is twofold lower in Asian men than Europeans (9 g vs 21 g), a difference too large to be accounted for entirely in terms of body size (Diamond, 1986; Short, 1984). [. . .] Contrary to the general trend, Freeman (1934) observed that, at autopsy, American blacks had less heavy testes than American whites (13g vs 15g). [. . .] Subsequently Daniel, Fienstein, Howard-Peebles, and Baxley (1982) found no black-white difference in testicular volume among American adolescents, while Ajmani, Jain, and Saxena (1985) found larger scrotal circumference in Nigerians than Europeans (212.6 mm vs 195.1 mm or 8.37 in. vs 7.68 in.)
Strangely, by 2000, Rushton seems to have grown somewhat amnesiac [1]:
Race differences in testicle size have also been measured (Asians = 9 grams, Europeans = 21 g). This is not just because Europeans have a slightly larger body size. The difference is too large. A 1989 article in Nature, the leading British science magazine, said that the difference in testicle size could mean that Whites make two times as many sperm per day as do Orientals. So far, we have no information on the relative size of Blacks.
Rushton also conveniently ignores "A French Army Surgeon" where the latter's claim fails to line up with the former's theory:
In no branch of the human race are the male organs more developed than in the African Negro. I am speaking of the penis only and not of the testicles, which are often smaller than those of the majority of Europeans.

Vaginal size

Rushton claims (apparently again relying on "A French Army Surgeon"):
Women were proportionate to men, with Orientals having smaller vaginas and blacks larger ones, relative to Caucasians.
Modern studies fail to bear out this claim, which tends to further reduce the credibility of Rushton's 19th-century source. One study using MRI finds "[r]ace was not associated with any differences in measurements of vaginal dimensions" [5]. A different study finds [6]:
posterior cast length is significantly longer, anterior cast length is significantly shorter and cast width is significantly larger in Hispanics than in the other two groups and (2) the Caucasian introitus is significantly greater than that of the Afro-American subject.
Nor do the "Afro-American" subjects have deeper vaginas: "[a]verage rod lengths for Caucasians and Afro-Americans were 11.51 and 11.18 cm [. . .] significantly different as measured by t test" [6].


[1] Race, Evolution, and Behavior 2nd Special Abridged Edition (pdf)

[2] Rushton, J.P. & Bogaert, A.F. (1987) Race differences in sexual behavior: Testing an evolutionary hypothesis. Journal of Research in Personality 21(4): pp. 536-7 (link)

[3] Orakwe JC et al. Can physique and gluteal size predict penile length in adult Nigerian men? West Afr J Med. 2006 Jul-Sep;25(3):223-5. (link)

[4] Ajmani ML et al. Anthropometric study of male external genitalia of 320 healthy Nigerian adults. Anthropol Anz. 1985 Jun;43(2):179-86. (link)

[5] Barnhart KT et al. Baseline dimensions of the human vagina. Hum Reprod. 2006 Jun;21(6):1618-22. Epub 2006 Feb 14. (link)

[6] Pendergrass PB et al. Comparison of vaginal shapes in Afro-American, caucasian and hispanic women as seen with vinyl polysiloxane casting. Gynecol Obstet Invest. 2000;50(1):54-9. (link)

[7] WHO Global Programme on AIDS. Specification and Guidelines for Condom Procurement. Appendix VII, Regional or Ethnic Differences in Erect Penis Size. Geneva: WHO, 1995. (pdf)

Ancient Mongolian mtDNA

I'd be more interested in Y-DNA results from the same time and place, which might help support or refute the "Genghis Khan" Y signature claim. The unsurprising presence of European morphological features in some skeletons is perhaps attributable to admixture by Iranian speakers, which would also likely be detected in a Y-DNA analysis.
American Journal of Physical Anthropology; Published Online: 25 Jul 2008

Ancient DNA analysis of human remains from the upper capital city of Kublai Khan

Yuqin Fu et al.

ancient DNA • mitochondrial DNA • human origins • China

Analysis of DNA from human archaeological remains is a powerful tool for reconstructing ancient events in human history. To help understand the origin of the inhabitants of Kublai Khan's Upper Capital in Inner Mongolia, we analyzed mitochondrial DNA (mtDNA) polymorphisms in 21 ancient individuals buried in the Zhenzishan cemetery of the Upper Capital. MtDNA coding and noncoding region polymorphisms identified in the ancient individuals were characteristic of the Asian mtDNA haplogroups A, B, N9a, C, D, Z, M7b, and M. Phylogenetic analysis of the ancient mtDNA sequences, and comparison with extant reference populations, revealed that the maternal lineages of the population buried in the Zhenzishan cemetery are of Asian origin and typical of present-day Han Chinese, despite the presence of typical European morphological features in several of the skeletons. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.


Genetics of criminality

Press release:
In one of the first studies to link molecular genetic variants to adolescent delinquency, sociological research published in the August issue of the American Sociological Review identifies three genetic predictors--of serious and violent delinquency--that gain predictive precision when considered together with social influences, such as family, friends and school processes.

[. . .]

The three genetic polymorphisms that predict delinquency include:

1. the 30-base pair (bp) promoter-region with a variable number tandem repeat (VNTR) in the monoamine oxidase A (MAOA) gene,

2. the 40-bp VNTR in the dopamine transporter 1 (DAT1) gene and

3. the Taq1 polymorphism in the dopamine D2 receptor (DRD2) gene. MAOA regulates several brain neurotransmitters important in behavioral motivation, aggression, emotion and cognition (e.g., serotonin, dopamine, norepinephrine).
The paper:
The Integration of Genetic Propensities into Social-Control Models of Delinquency and Violence among Male Youths

Authors: Guo, Guang; Roettger, Michael E.; Cai, Tianji

Source: American Sociological Review, Volume 73, Number 4, August 2008 , pp. 543-568(26)

This study, drawing on approximately 1,100 males from the National Longitudinal Study of Adolescent Health, demonstrates the importance of genetics, and genetic-environmental interactions, for understanding adolescent delinquency and violence. Our analyses show that three genetic polymorphisms—specifically, the 30-bp promoter-region variable number tandem repeat (VNTR) in MAOA, the 40-bp VNTR in DAT1, and the Taq1 polymorphism in DRD2—are significant predictors of serious and violent delinquency when added to a social-control model of delinquency. Importantly, findings also show that the genetic effects of DRD2 and MAOA are conditional and interact with family processes, school processes, and friendship networks. These results, which are among the first that link molecular genetic variants to delinquency, significantly expand our understanding of delinquent and violent behavior, and they highlight the need to simultaneously consider their social and genetic origins.
My guess is genetic differences such as these (along with IQ) will ultimately be shown to account for a much larger fraction of cross-racial variation in crime than racial differences in circulating testosterone levels (which seem far from fixed). I don't have population frequency data for the specific polymorphisms mentioned above, but the SNP rs979606 in MAOA, for example, varies in the familiar Asian <> European <> African pattern. Update: Racial differences are also apparent in DRD2 Taq1 genotypes and the DAT1 40 bp VNTR, though their meaning is not clear to me yet.

Another relevant paper:
Neuropsychopharmacology (2008) 33, 425–430; doi:10.1038/sj.npp.1301417; published online 11 April 2007

A Non-Additive Interaction of a Functional MAO-A VNTR and Testosterone Predicts Antisocial Behavior

Rickard L Sjöberg et al.


A functional VNTR polymorphism in the promoter of the monoamine oxidase A gene (MAOA-LPR) has previously been shown to be an important predictor of antisocial behavior in men. Testosterone analogues are known to interact with the MAOA promoter in vitro to influence gene transcription as well as in vivo to influence CSF levels of the MAO metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG) in human males. We examined the possible joint effects of testosterone (measured in CSF) and MAOA-LPR genotype on antisocial personality disorder and scores on the Brown–Goodwin Aggression scale in 95 unrelated male criminal alcoholics and 45 controls. The results confirm that MAOA genotype and CSF testosterone interact to predict antisocial behaviors. The MAOA/testosterone interaction also predicted low levels of CSF MHPG, which tentatively suggests the possibility that the interaction may be mediated by a direct effect on gene transcription. If replicated these findings offer plausible explanations for previous inconsistencies in studies of the relationship between testosterone and male human aggression, as well as for how MAOA genotype may influence aggressive behavior in human males.

antisocial personality disorder, antisocial behavior, MAO-A gene, testosterone, gene by hormone interaction, MHPG

Confounding factors in 2D:4D studies

This tends to reinforce my doubts about the meaningfulness of direct comparisons of digit ratio across groups.

American Journal of Physical Anthropology; Published Online: 9 Jul 2008

Brief Communication: Latent toxoplasmosis and salivary testosterone concentration - Important confounding factors in second to fourth digit ratio studies

Jaroslav Flegr et al.

infection • postnatal changes • Toxoplasma • androgens • 2D:4D

A sexually dimorphic characteristic, the second to fourth digit ratio (2D:4D ratio), has been shown to reflect the prenatal concentration of sex steroid hormones and to correlate with many personality, physiological, and life history traits. The correlations are usually stronger for the right than the left hand. Most studies have shown that the 2D:4D ratio does not vary with age or postnatal concentration of sex steroid hormones. Recently, a strong association between left hand 2D:4D ratio and infection with a common human parasite Toxoplasma has been reported. We hypothesized that the confounding effect of Toxoplasma infection on left hand 2D:4D ratio could be responsible for the stronger association between different traits and right hand rather than left hand 2D:4D ratio. This confounding effect of toxoplasmosis could also be responsible for the difficulty in finding an association between 2D:4D ratio and age or postnatal steroid hormone concentration. To test this hypothesis, we analyzed the association between sex and age and 2D:4D ratio in a population of 194 female and 106 male students with and without controlling for the confounding variables of Toxoplasma infection and testosterone concentration. Our results showed that the relationship between age and sex and 2D:4D ratio increased sharply when Toxoplasma infection and testosterone concentration were controlled. These results suggest that left hand 2D:4D ratio is more susceptible to postnatal influences and that the confounding factors of Toxoplasma infection, testosterone concentration and possibly also age, should be controlled in future 2D:4D ratio studies. Because of a stronger 2D:4D dimorphism in Toxoplasma-infected than Toxoplasma-free subjects, we predict that 2D:4D ratio dimorphism as well as right hand/left hand 2D:4D ratio dimorphism will be higher in countries with a high prevalence of Toxoplasma infection than in those with a low prevalence. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc.