Showing posts with label testosterone. Show all posts
Showing posts with label testosterone. Show all posts

Testosterone-related abstracts from AAPA 2016

Facial width-to-height ratio (fWHR) is not associated with pubertal testosterone
Several researchers have proposed that facial width-to-height ratio (fWHR) is a sexually dimorphic signal that develops under the influence of pubertal testosterone (T); however, this hypothesis is currently under supported. Here we examine the association between fWHR and T during the period of the life span when facial growth is canalized--adolescence. To do so, we examine the association between T, known T-derived traits (i.e. strength and voice pitch), and craniofacial measurements in a sample of adolescent Tsimane males. If fWHR variation derives from pubertal T’s influence on craniofacial growth, several predictions can be made: 1) fWHR should increase with age as T increases, 2) fWHR should reflect adolescent T (rather than adult T per se), 3) fWHR should exhibit a growth spurt in parallel with T, 4) fWHR and T should correlate after controlling for potential confounds, and 5) fWHR should show a strong relationship to other T-derived traits. These effects were not observed. We also examined three additional facial masculinity ratios: facial width/lower face height, cheekbone prominence, and facial width/full face height. In contrast to fWHR, each of the three additional measures exhibit a strong age-related pattern of change and are associated with both T and T-dependent traits. In summary, our results challenge the status of fWHR as a sexually-selected signal of pubertal T and T-linked traits.
The relationship between social status, body size, and salivary hormone levels among Garisakang forager-horticulturalist men of lowland Papua New Guinea
Social hierarchy is a robust phenomenon that exists within all human societies. Over the past several decades, a growing body of evidence from industrialized Western populations has suggested that social status is closely related to individual measures of stress, health, and many other fitness-related traits. Data regarding such relationships, however, remain rare among small-scale subsistence societies, preventing a clear understanding of the importance of social position for fitness cross-culturally. Here we contribute to this area of research by exploring the relationship between adult male social status, BMI, and levels of salivary testosterone and diurnal cortisol among Garisakang small-scale forager-horticulturalists of lowland Papua New Guinea (N = 32). Three measures of individual social status – Respect, Dominance and Prosociality – were extracted from principal components analysis of photo-rank data for locally valued male traits (e.g., sociability, hunting ability, community influence). Preliminary results from multiple regression models controlling for age suggest complex relationships between social status, body size, and salivary hormone levels among the Garisakang. Male Dominance is positively related to BMI (p < 0.05) but not with salivary hormone measures, while greater male Respect is associated with reduced salivary cortisol (p = 0.06) but not testosterone or BMI. Prosociality, conversely, is not significantly related to any evaluated measure. We discuss the evolutionary implications of our findings, with a focus on future directions for investigating the biocultural interface of health in this population.
Men’s reproductive ecology and diminished hormonal regulation of skeletal muscle phenotype: An analysis of between- and within-individual variation among rural Polish men
Human life history is characterized by several distinctive features—sexual division of labor, prolonged care of altricial young, multiple dependents of different ages, and male provisioning. Testosterone has been suggested to mediate a trade-off between men’s reproduction and survival, through the regulation of sexually dimorphic musculature. This hypothesis predicts a relationship between testosterone and musculature in which mating effort, elevated testosterone, and dimorphic musculature covary positively. Testosterone is also posited to mediate a trade-off between mating and parenting effort, and accordingly, investing fathers show decreased testosterone production. Because men use their musculature not only in mating competition but also to support work demands, an important component of parenting effort, a relatively fixed relationship between testosterone and muscularity would seem maladaptive. We hypothesize that men’s parenting effort, specifically provisioning and subsistence activities, becomes a primary determinant of muscularity. Life history, anthropometric, and hormonal data were collected from 122 rural Polish men (at the Mogielica Human Ecology Study Site) during the summer harvest and for 103 of these participants in the winter. We found that fatherhood jointly predicted heavier workload and decreased testosterone, but positively predicted muscle mass and strength measures. Furthermore, within-individuals, men experienced intensified workload and suppressed testosterone during summer, along with a concomitant increase in muscularity and strength. These findings provide preliminary support for our model, termed the ‘Paternal Provisioning Hypothesis’. Between and within individuals, men’s provisioning and subsistence activities were robust predictors of muscular development and performance, whereas their testosterone levels had no appreciable effect on skeletal muscle phenotype.
Testosterone, musculature, and development in Kanyawara chimpanzees and Tsimane forager-horticulturalists
Considerable evidence suggests that the steroid hormone testosterone mediates major life-history trade-offs in primates, promoting mating effort at the expense of parenting effort or survival. In many species, chronic shifts in testosterone production over the life course correlate with investment in male-male competition. Chimpanzees and humans represent interesting test cases, because although closely related, they maintain divergent mating systems. Chimpanzee males do not invest in pair bonds or paternal care. Consequently, across the lifespan, their testosterone levels are expected to track changes in (1) behavioral investment in dominance striving, and (2) investment in sexually dimorphic musculature employed in male-male competition. Humans, by contrast, are expected to show weaker associations between testosterone and musculature, because the latter is important not only for male competition, but for men’s work provisioning wives and children. We assayed >7000 chimpanzee and >3350 Tsimane urine samples for testosterone, creatinine, and specific gravity, in the same laboratory using the same assay methods. Male chimpanzees showed peak acceleration in testosterone increase at age 6, peak velocity at age 10, and peak deceleration at age 14, reaching adult levels by 15-16, when they began to challenge other adult males. Adult levels of testosterone were achieved 3 years later than in captivity, likely reflecting energetic constraints in the wild. Indirect measures of muscle mass followed a similar pattern, and were highly correlated with testosterone. As predicted, Tsimane men exhibited a weaker correlation, with testosterone accounting for half as much variance in the muscle mass measure as in the chimpanzee sample.
Dads and cads? Male reproductive success, androgen profiles, and male-infant social bonds in wild mountain gorillas (Gorilla beringei beringei)
Male reproductive strategies are often reduced to a ‘dad versus cad’ dichotomy. When paternity certainty is high and mating opportunities scarce, theory predicts high levels of paternal investment; if paternity certainty is low and/or access to mating opportunities plentiful, male parenting is expected to be scarce. However, conflict between mating and parenting behavior is not equally strong across ecologies and social structures. Wild mountain gorillas (Gorilla beringei) have variable paternity certainty and a morphology suggestive of intense male contest competition. Despite this, relationships between males and infants are an important component of group structure, likely because males protect infants from infanticide and predation. Using data from gorilla groups monitored by the Dian Fossey Gorilla Fund’s Karisoke Research Center, we evaluated 1) the relationship between male-infant social bond strength and males’ reproductive success, and 2) the relationship between male-infant social bonds and males’ fecal androgen metabolite levels. Higher testosterone levels are generally correlated with increased aggression and mating activity, which are typically considered incompatible with parenting behavior. After controlling for male age and rank, males who had the strongest social bonds with infants were also the males with the highest reproductive success. There was no relationship between strength of male-infant social bonds and fecal androgen metabolite levels. Results demonstrate that reductive descriptions of male reproductive strategies may obscure important connections between mating and parenting effort, and highlight the need for additional data on the relationship between androgen activity, mating, and parenting in multimale/multifemale social systems.

Prenatal exposure to tylenol lowers testosterone and sperm counts

Given that "paracetamol sales in Denmark have been estimated among the highest in the world" and paracetamol consumption is evidently much lower in Finland, this may turn out to be a substantial part of the explanation of this phenomenon: East–West gradient in semen quality in the Nordic–Baltic area: a study of men from the general population in Denmark, Norway, Estonia and Finland

There's been epidemiological evidence pointing in this direction for years, but more direct evidence, from a xenograft model, has now been reported.

Pregnant women are advised to seek medical advice if they need paracetamol for more than one day

Pregnant women are being advised to see their doctor if they need to take paracetamol for more than a day, after researchers found in an animal study that prolonged use of the analgesic reduced the production of testosterone.1

Four previous studies have linked the use of paracetamol in pregnancy with an increased risk of cryptorchidism in male babies, but a causal effect has not been shown because it is not possible to test the association in women. To overcome this, researchers from the University of Edinburgh developed an animal model using castrated mice, into which they grafted human testicular tissue. These grafts have been shown to mimic how the developing testes grow and function in pregnancy.

Prolonged exposure to acetaminophen reduces testosterone production by the human fetal testis in a xenograft model
Most common male reproductive disorders are linked to lower testosterone exposure in fetal life, although the factors responsible for suppressing fetal testosterone remain largely unknown. Protracted use of acetaminophen during pregnancy is associated with increased risk of cryptorchidism in sons, but effects on fetal testosterone production have not been demonstrated. We used a validated xenograft model to expose human fetal testes to clinically relevant doses and regimens of acetaminophen. Exposure to a therapeutic dose of acetaminophen for 7 days significantly reduced plasma testosterone (45% reduction; P = 0.025) and seminal vesicle weight (a biomarker of androgen exposure; 18% reduction; P = 0.005) in castrate host mice bearing human fetal testis xenografts, whereas acetaminophen exposure for just 1 day did not alter either parameter. Plasma acetaminophen concentrations (at 1 hour after the final dose) in exposed host mice were substantially below those reported in humans after a therapeutic oral dose. Subsequent in utero exposure studies in rats indicated that the acetaminophen-induced reduction in testosterone likely results from reduced expression of key steroidogenic enzymes (Cyp11a1, Cyp17a1). Our results suggest that protracted use of acetaminophen (1 week) may suppress fetal testosterone production, which could have adverse consequences. Further studies are required to establish the dose-response and treatment-duration relationships to delineate the maximum dose and treatment period without this adverse effect.

Racial and ethnic variation in penis size, pt. 2: the actual data

Here is most of the relevant published data I know of (but keep in mind the issues touched on in the previous post):

My impression:

  • While there are probably some real differences between populations, differences among different Caucasoid and Negroid populations, at least, appear to be greater than any overall differences between macroraces. I don't find this surprising, since if we looked at, say, height, the same would probably be true.
  • I'm not convinced the data support any difference between Northern Europeans and West Africans, and if differences exist, they are relatively minor.
  • To the extent we can say anything about intra-Caucasoid differences, there appears to be a trend of declining penis size from Northern/western Europe towards SE Europe, the Middle East, and South Asia.
  • Reported values for East Asia do appear to tend toward the low end among worldwide populations.

Related posts:

Racial and ethnic variation in penis size, pt. 1: some background

A few years ago, a "World Penis Size Map" [1] citing a website containing largely made-up numbers [2] entered widespread circulation. Despite being an obvious and inept hoax, it has continued to take in various people, including the press, some economist [3], and Richard Lynn [4]. I started writing up a post at the time, but never bothered to finish it.

Most recently, a presenter at the 2015 London Conference on Intelligence has attempted to defend this hoax data, claiming:

  • Lynn (2013) attempted to resolve the controversy by obtaining data from the World Penis Website, which listed average national penis lengths based on various sources. Using this, Lynn extended Rushton?s model, based on this, to other races, and found that their average penis sizes differed as Differential K would predict.
  • This paper was ridiculed, most notably by a psychologist blogger called Scott McGreal, who pointed out various minor mistakes on the World Penis Website, insisting all its contents was suspect and not properly reviewed
  • As I am researching a book that extends Rushton?s theory to 12 races, I was very interested in Lynn?s penis data. It occurred to me that we can test the validity of Lynn?s national penis lengths by seeing if they correlated with other national measures androgen in the expected direction.
But the website does not just feature a few "minor mistakes". Most of the data is simply made up. One can't "validate" made-up numbers by attempting to correlate them with other putative markers of androgen exposure.

Garry Trudeau: weak, sensitive boy traumatized by prep school, not a product of "old money liberalism"

"Old money liberalism" is a myth. The idea that upper class "WASPs" as a group lean left is a product of 1950s "conservative" political correctness and various combinations of aspirational leftist self-deception and manipulation.

Steve Sailer writes:

For example, consider Garry Trudeau. He was a scion of old money liberal Protestant good blood good bone folks (his mother went to Miss Porter’s School, for example)
1. Let's not exaggerate the wealth or social standing of Trudeau's family. While I don't doubt they easily fell within the top 5% in both respects, thousands of people of Trudeau's generation were born into richer families with more impressive ancestors, and most of these people did not become obnoxious leftists.

Trudeau's father and paternal ancestors going back several generations were doctors. His mother's father was a sales manager and Republican politician. Certainly respectable and likely prosperous people, but I'd say they belonged to the multigenerational upper middle class rather than the upper class.

2. It would have been more helpful for this narrative if Garry Trudeau's parents were actually liberal. Trudeau's mother belonged to a Continuing Anglican church. Trudeau's parents were Republicans. They did not encourage their son's faggotry. A fan lazily (or wishfully) attempts to frame Trudeau's leftism in terms of the make-believe construct of "old money liberalism":

Members of Trudeau's more recent family tree were not rabidly Republican, but their politics, perhaps because of their privileged social status, leaned to the right. As an educated, civically engaged family, they saw themselves as belonging, nevertheless, to a tradition of liberal egalitarianism. In his satire he has made the dissonance of these competing ideologies a major theme, continually returning to the ironies and hypocrisies of individuals and a society built on such conflicted ideas. In addition, having been raised at the intersection of the ethics of aristocratic gentility and liberal idealism, Trudeau seems to have adopted a sense of noblesse oblige that has fueled both his selfless devotion to promoting social justice through satire, as well as his supreme confidence in his worldview, his business ethics, and his position as social chronicler.

One may also speculate that Trudeau's populist indignation at corrupt authority, nepotism, and old-boy networks is rooted in a need to exorcise a sense of lingering guilt at having such fortunate opportunities. It has even been speculated that the depth of his intense loathing for the Bush family comes from his need to differentiate his own privileged, WASPy persona--one that is tempered by self-criticism and a championing of social underdogs--from that of other Ivy Leaguers who, from his perspective, have seemingly used their background and connections to increase their own wealth and power. For example, those strips which mock the elder Bush for his participation in the closed Skull and Bones society at Yale (the university attended by Trudeau as well) reflect a vehemence and particularity that belies his deep-seated, especially personal dislike for this other type of New England family. (At the same time, one could argue that the Bush family's adoption of swaggering, folksy, Texan personas was an effort to distance themselves from the type of liberal New England elitism they saw in families like Trudeau's; Bush indicated as much in 1988, when he charged that Trudeau only spoke "for a bunch of Brie-tasting, Chardonnay-sipping elitists" [Alter 67].)

But no support whatsoever is offered for claims that the family professed "a tradition of liberal egalitarianism" (nor have I been able to find evidence for this elsewhere), and his parents do not seem to have been active in politics.

(As for the assumed connection to New England, only one of Trudeau's great-grandparents was born in Vermont; the other seven and proceeding generations were born in the mid-Atlantic. In total, no more than 1/4 of Trudeau's ancestry traces back to New England; 1/8 of Trudeau's ancestry is French, his great, great-grandfather having been an evidently incompetent Confederate officer and doctor from New Orleans; the remainder of his ancestry came by way of the mid-Atlantic and includes Dutch and German.)

The facts actually presented by this author paint a picture not of a self-assured aristocrat driven by a sense of noblesse oblige and carrying on a tradition of "liberal idealism" picked up from his family, but of a sensitive bitch who couldn't hang with other members of his class, who because of this developed a resentment of winners, and who imbibed his liberalism from popular culture.

By Trudeau's own description, he was an awkward teenager. Physically weak, athletically slow, pigeon-toed, and small for his age, he did not fit into the popular crowd. About his time at St. Paul's prep school in New Hampshire, he says, "I was not the class clown. In fact, I was pretty shy. . . . [It was a] tortured time for me [because] I was the second or third smallest in my class" (Alter 64). As a result of being ostracized from the elite cliques at school, Trudeau's inner, imaginative life was given ample time and space to develop. He found solace in art--an interest that did not help his social life; a classmate recalls that the prep school was "an unbelievably bad climate to be an artist," and as a result, "Garry took a lot of grief" ("Doonesbury: Drawing and Quartering" 60).

The traumas of his teen years--including seeing his parents divorce--gave him ulcers and probably contributed to his career-long sympathy for people in minority or underdog positions in society. He has little nostalgia for this awkward period in his life; for example, he stated in an interview in 1986 that "Adolescence is, I think, an unpleasant time of life no matter where you spend it and with whom you spend it. I didn't like being a teenager. I didn't like teenagers when I was one. And I still don't like them. It's a very selfish time of life" (Grove D15).

As Trudeau entered into his young adult years--the point at which he was expected to follow his father's lead in becoming a physician--his interest in art and theater put him at odds with his extended family. One can see how Trudeau's creative and sensitive personality did not mesh his father's worldview, a philosophy that can best be summarized in the maxim he repeated often to his son: "Life is not something to be enjoyed, so just get on with it" (Weingarten W14). In some way the disconnect between Trudeau's aspirations and his family's expectations was typical of many family conflicts in the late 1960s when staid lifestyles of the older generation clashed with the newly bohemian, countercultural ethics of their children. Trudeau was not a rebellious kid in any radical sense, but his affinity for the arts seemed to place him within the general parameters of this dissenting youth culture. Trudeau jokes that during his teen years his grandmother "would plead with my parents to send me to Outward Bound, because she had read in Life that the counselors were very good at reaching troubled teens" (Trudeau, Flashbacks 90). [. . .]

In light of Trudeau's adult dedication to following politics with a wonk-like intensity, it is interesting to note that, although he had vague countercultural leanings as a youth, he did not have a deep understanding of politics or any strong convictions about particular parties or candidates during his formative years. Here he describes this teenage detachment:

I wasn't particularly politically attuned growing up. There wasn't much debate at our dinner table. My parents were Republicans, so the GOP was my team, and Ike was our genial manager. In '60, I was too young to really respond to JFK's charisma as intuitively as I was repelled by Nixon's sleaziness, and in 1964, I was so disengaged that I actually designed placards for both parties at my high school. Later I came to admire Robert Kennedy and Martin Luther King, but more as pop figures than as visionaries who changed the world. Vietnam was the wake-up call. That's when I really started paying attention, and by then heroes were in scarce supply. Besides, who needed role models? We had the certainty of youth. (Bates 62)

[. . .] This gradual success of the strip also won for Trudeau some grudging praise from his family. His father offered him barbed congratulations, saying, "You're lucky you were born when you were. In my day you'd have been a loser" (Trudeau, Flashbacks 16). Similarly, his mother quipped after hearing he had won a Pulitzer Prize in 1975, "I'm perfectly thrilled and delighted. I've kept my fingers crossed for fear he might end up in jail" (Trudeau, "Investigative Cartooning" C1).

[Kerry Soper. Garry Trudeau: Doonesbury and the Aesthetics of Satire.]

Size Matters: How Height Affects the Health, Happiness, and Success of Boys--and the Men They Become
Wherever boys play games, as on the playing fields of nature, where predation and aggression have shaped animal behavior for tens of millions of years, sheer size makes a difference. You won't find that fact in many textbooks, but it may be the single most important lesson of unsupervised schoolboy existence.

The way those feelings of beleaguerment, insecurity, and behavioral adaptation live on in an adult psychology has been insightfully captured by the cartoonist Garry Trudeau, the creator of Doonesbury. In a lovely 1996 essay called "My Inner Shrimp," Trudeau admits that "for the rest of my days, I shall be a recovering short person" with "the soul of a shrimp." Trudeau, unlike some of us, benefited from a delayed but explosive growth spurt that propelled his final height to over six feet. But it's the feelings he experienced at age fourteen, when he was the third-smallest kid in his high school class, that still perfuse his adult soul. Trudeau sometimes pondered going to a high school reunion to show off all those postpubertal inches. But the Little Man Inside nixed the idea.

"Adolescent hierarchies," he writes, "have a way of enduring; I'm sure I am still recalled as the Midget I myself have never really left behind."

Related:

We do have some preliminary evidence that Conservatives and Liberals vary, on average, in their testosterone-estrogen ratios, with Conservatives males higher on the testosterone side, and Conservative females higher on the estrogen side. This means that the Liberal females and males are closer to each other in their testosterone-estrogen ratios, and the Conservatives further apart.
Formidability and the logic of human anger
Individuals with enhanced abilities to inflict costs (e.g., stronger individuals) or to confer benefits (e.g., attractive individuals) have a better bargaining position in conflicts; hence, it was predicted that such individuals will be more prone to anger, prevail more in conflicts of interest, and consider themselves entitled to better treatment. These predictions were confirmed. Consistent with an evolutionary analysis, the effect of strength on anger was greater for men and the effect of attractiveness on anger was greater for women. Also as predicted, stronger men had a greater history of fighting than weaker men, and more strongly endorsed the efficacy of force to resolve conflicts—both in interpersonal and international conflicts.
Facial Structure May Predict Endorsement of Racial Prejudice

Studies have shown that facial width-to-height ratio (fWHR) is associated with testosterone-related behaviors, which some researchers have linked with aggression. But psychological scientist Eric Hehman of Dartmouth College and colleagues at the University of Delaware speculated that these behaviors may have more to do with social dominance than outright aggression.

[. . .] “Racial prejudice is such a sensitive issue and there are societal pressures to appear nonprejudiced. More dominant individuals might care less about appearing prejudiced, or exercise less self-regulation with regard to reporting those prejudices, should they exist,” says Hehman, who conducted the research as a graduate student at the University of Delaware.

The researchers asked male participants about their willingness to express racially prejudiced beliefs and about the pressure they feel to adhere to societal norms. The results revealed that men who have higher fWHR (determined from photos of their faces) are more likely to express racist remarks and are less concerned about how others perceive those remarks.

Alex Shoumatoff on St. Paul's School
For the past 150 years St. Paul’s School, the “exclusive” (as it is invariably called) boarding school in Concord, New Hampshire, has been the Eton of America’s upper crust. Or perhaps it is its Hogwarts, as Harry Potter’s fictional academy is called, providing the country with many of its most accomplished wizards—not just at making money, although that is what its graduates have tended to do, but in practically every endeavor. Its main constituency has traditionally been the conservative old Wasp families of New York, Boston, and Philadelphia—the plutocracy that has been running the country for generations. But this is changing. Since the first black student was admitted—in my class, which graduated in 1964—the school’s admissions policy has been progressively more meritocratic. The “natural aristocracy,” based on virtue and talent, to use Thomas Jefferson’s distinction, has been displacing the “artificial aristocracy,” based on wealth and birth. Every year there are fewer “legacies,” fewer fourth- or fifth-generation Paulies, among the 533 students, who now come from 37 states and 21 countries.

Despite its reputation for being a breeder of staunch, old-line Republicans, St. Paul’s has also turned out a distinguished roster of liberals, including the cartoonist Garry Trudeau and Senator John Kerry. Kerry was in the class of ’62, two years ahead of me, and even then he seemed to be plotting his run for the presidency. [. . .]

The fourth element of the St. Paul’s calamity had been incubating for years: the allegations that, from the late 1940s through the early 90s, dozens of the school’s masters (as the teachers were known until women joined the faculty, in 1972), including several revered ones, had sexually molested students. [. . .] But boarding schools attract sexually conflicted adults. [. . .]

The faculty was also at odds with the rector and the board. Partly it was because the teachers were liberals, and the trustees were for the most part stodgy conservatives “who have not crossed the postmodern line into the world with the rest of us,” as one faculty member put it. And partly it was a class issue: the trustees acted as if the teachers were underlings, when in fact it is the teachers who dedicate their lives and careers to fulfilling the school’s mission.

EthnicMuse's race and testosterone "meta-analysis"

A commenter asks:

What do you think of this website and his analysis of testosterone levels in different racial groups?

https://ethnicmuse.wordpress.com/tag/testosterone/

"EthnicMuse" is attempting to aggregate numbers that can't be aggregated, and the results lack face validity. T levels as measured by different techniques and/or at different laboratories are not in general directly intercomparable.
Clinicians are being presented with normal male reference ranges for serum T from these automated platforms that have low end clinical limits down to 170–200 ng/dl (5.9–6.9 nmol/liter) and upper range limits of 700–800 ng/dl (24.3– 27.7 nmol/liter). These stated reference ranges provided by the manufacturer are significantly lower than the 300-1000 ng/dl (10.4–34.7 nmol/liter) reference range referred to in numerous publications over the past 30 yr based on tradi- tional RIA methods with or without the chromatography step as well as some research techniques employed by in- ternal recovery standards to correct for procedural losses (5).

External quality control programs such as that provided by the College of American Pathologists allow laboratories to compare results with other laboratories using the same method or kit reagents. As shown in Table 1, the median value of a quality control sample (Y-04,2002) varied between 215 and 348 ng/dl (7.5 and 12.0 nmol/liter) among methods with coefficients of variation among laboratories using the same method or instrument ranging between 5.1% and 22.7%. The median average for this sample from all methods was 297 ng/dl (10.3 nmol/liter) and results were as low as 160 or as high as 508 ng/dl (5.5 to 17.6 nmol/liter). These results span the hypogonadal to eugonadal range.

[Measurement of Total Serum Testosterone in Adult Men: Comparison of Current Laboratory Methods Versus Liquid Chromatography-Tandem Mass Spectrometry]

Differences that are to be expected between different assays and different laboratories, apart from any other factors, would likely swamp any anticipated racial differences in circulating testosterone levels. Between-study differences in collection times, sample handling, age and health condition of subjects, and so on, add further noise.

I see that EM is at least vaguely aware of these issues, but he rationalizes publishing his "meta-analysis" as follows:

One cannot and should not compare different testosterone studies with different measurement methods. However, for the race-realist purpose of aggregating data, there is nothing inherently wrong with what the PDF file lists. If JP Rushton can use a few studies and make wild claims which are then used by the Internet-o-sphere, using 150 independent peer-reviewed sources with large samples is much more scientific than anything similar from the race realist community. [. . .]

Age differences will affect the results but healthy males should have negligible decreases. Assuming a 0.4% annual decline from 5000 pg/ml after age 40, a man at 80 should have 4275 pg/mL, less than a 15% difference if my spreadsheet math is correct. It would have been better to normalize for age. So while the tabled rankings is flawed, the point is that the entire issue is flawed as there is no standard measuring method in the first place. That race realists routinely use flawed data should be the issue but …

That blindly aggregating data from disparate studies (which in this realm I've never seen anyone other than EM attempt) is nonsensical does not mean all attempts at comparing circulating testosterone levels between races are "flawed". It means that if one wants to attempt such comparisons, one should focus on studies in which a single set of researchers, using standardized methods, publish results for multiple ethnic groups.

EM is aware, for example, of a study (pdf) in which blood samples from Swedes and Koreans "were analyzed in the same laboratory using the same assay". The result (in EM's words): "the Swedes had 25% more T than the Koreans in this study". I've seen other studies showing lower or similar levels of testosterone in East Asians compared to whites (and none showing anything like the 10% higher testosterone in East Asians asserted by EM). But EM apparently did not like where the data pointed (thus his version of "meta-analysis", in which valid data is swamped with garbage).

Testosterone and intergroup competition

Does Competition Really Bring Out the Worst? Testosterone, Social Distance and Inter-Male Competition Shape Parochial Altruism in Human Males
Parochial altruism, defined as increased ingroup favoritism and heightened outgroup hostility, is a widespread feature of human societies that affects altruistic cooperation and punishment behavior, particularly in intergroup conflicts. Humans tend to protect fellow group members and fight against outsiders, even at substantial costs for themselves. Testosterone modulates responses to competition and social threat, but its exact role in the context of parochial altruism remains controversial. Here, we investigated how testosterone influences altruistic punishment tendencies in the presence of an intergroup competition. Fifty male soccer fans played an ultimatum game (UG), in which they faced anonymous proposers that could either be a fan of the same soccer team (ingroup) or were fans of other teams (outgroups) that differed in the degree of social distance and enmity to the ingroup. The UG was played in two contexts with varying degrees of intergroup rivalry. Our data show that unfair offers were rejected more frequently than fair proposals and the frequency of altruistic punishment increased with increasing social distance to the outgroups. Adding an intergroup competition led to a further escalation of outgroup hostility and reduced punishment of unfair ingroup members. High testosterone levels were associated with a relatively increased ingroup favoritism and also a change towards enhanced outgroup hostility in the intergroup competition. High testosterone concentrations further predicted increased proposer generosity in interactions with the ingroup. Altogether, a significant relation between testosterone and parochial altruism could be demonstrated, but only in the presence of an intergroup competition. In human males, testosterone may promote group coherence in the face of external threat, even against the urge to selfishly maximize personal reward. In that way, our observation refutes the view that testosterone generally promotes antisocial behaviors and aggressive responses, but underlines its rather specific role in the fine-tuning of male social cognition.

Black men have lower sperm counts than white men

Semen parameters in fertile US men: the Study for Future Families

The Study for Future Families (SFF) recruited men who were partners of pregnant women attending prenatal clinics in Los Angeles CA, Minneapolis MN, Columbia MO, New York City NY and Iowa City IA. Semen samples were collected on site from 763 men (73% White, 15% Hispanic/Latino, 7% Black and 5% Asian or other ethnic group) using strict quality control and well-defined protocols. [. . .] Black men had significantly lower semen volume, sperm concentration and total motile sperm counts than White and Hispanic/Latino men.
This is consistent with the other evidence I'm aware of. Lower sperm counts have been noted in Africa, and a study in Rochester, NY, that included a small number of American blacks similarly found:
All sperm parameters were significantly lower in the small subgroup (n = 7) of African-American men compared with other men in this population (p-values for sperm parameters, < 0.001 to 0.016).
Also consistent with these results: the only autopsy studies I'm aware of (at least one of which Rushton knew of before he became selectively forgetful) both suggest black men have smaller/lighter testes than white men.

Opportunity costs, intelligence, and criminality

Cognitive ability and the division of labor in urban ghettos: Evidence from gang activity in U.S. data
Hernstein and Murray (1994) famously argued that the division of labor in modern society is determined by individual differences in cognitive ability. This paper shows that differences in cognitive ability can also determine the division of labor in poor urban areas. We estimate the effect of IQ on time-to-first gang participation with data from the National Longitudinal Survey of Youth (NLSY97) and Project on Human Development in Chicago Neighborhoods (PHDCN). Results from both the NLSY97 and PHDCN indicate that low-IQ is a robust predictor of gang participation. There are two plausible explanations of this main finding: (1) low-IQ individuals may have comparative advantage in violence as their opportunity costs of engaging in legal activities are low and (2) gangs may prefer low-IQ individuals as a way to reduce agency costs. We find strong evidence in support of the hypothesis that persons with lower IQs have comparative advantage in criminal activity in the PHDCN dataset. Highlights

► This paper shows that cognitive ability can determine the division of labor in poor urban areas. ► We estimate the effect of IQ on time-to-first gang participation with data from U.S. data. ► Results indicate low-IQ is a robust predictor of gang participation. ► A person's relative IQ, with respect to one's neighborhood peers, determines gang participation.

Related posts:

IQ, SES, and criminality

(Via Chuck.) Elaboration on the association between IQ and parental SES with subsequent crime. Personality and Individual Differences 50 (2011) 1233–1237. (pdf)
The current study, based on the nationally representative NLSY data, follows incarceration over a 24-year period. This represents the longest prospective examination of the NLSY crime data to date, since previous analyses have been shorter and is not prospective (Herrnstein & Murray, 1994). With the aim of providing greater confidence in the results, unlike prior analyses the current study uses three major criminological outcomes (onset, incidence and frequency of incarceration), and not one (incidence of incarceration). Based on theoretically reformulated associations between the study variables, the results show that low IQ, low parental SES and their interaction modestly predict the incidence of, frequency of and time to incarceration.

Theoretically, a low IQ may make coping and decision-making difficult and increase the likelihood of crime. Taken in isolation the association between low IQ and increased risk of crime in the current results may be taken as evidence that is consistent with the Bell Curve (Herrnstein & Murray, 1994). Concurrently, however, the present results also indicate that a low parental SES increases the risk of crime, potentially through an inadequate familial environment (Bradley & Corwyn, 2002). These family characteristics may include little emphasis on social attainment. Thus, the current findings indicate that the family environment may provide a route to influence the association between IQ and crime. This possibility is not considered in the Bell Curve view on crime that emphasizes neighborhood SES (Herrnstein & Murray, 1994), and is consistent with opponents to the Bell Curve (Fischer et al., 1996).

Collectively, however, the effects of IQ and parental SES on crime are modestly amplified, as captured by the interaction reflecting unfavorable conditions (i.e., particularly if both IQ and parental SES are low). A possible explanation of this interaction is that a disadvantaged home environment does not encourage social attainment and a low IQ makes coping and decision-making difficult. Taken together this increases the likelihood of crime. Thus these findings support an interactional perspective of crime. Their interpretation is consistent with the usually competing theoretical notions that contrast low SES (Fischer et al., 1996) or low IQ (Herrnstein & Murray, 1994) as factors that increase the likelihood of crime. [. . .]

This study does not separate genetic–environmental influences, unlike past research (e.g., Koenen, Caspi, Moffitt, Rijsdijk, & Taylor, 2006). SES may not purely be an environmental factor that is unrelated to IQ. Parents may give children both genes for IQ and SES (i.e., passive gene–environment associations), and a parent’s SES is partly based on their IQ as a result of life-long active gene–environment interactions. Accordingly, IQ and SES may be moderately correlated due to common genetic influences. Also, as the participants in this study mature, they become increasingly free to create their own environments, partly due to both IQ and SES. The current study, however, affords no assessment of genetics, or upward or downward social mobility, thereby highlighting key directions for future research.

Related posts:

No evidence for higher testosterone in black compared to white adolescent males

Racial/ethnic differences in serum sex steroid hormone concentrations in US adolescent males. Cancer Causes & Control. April 2013, Volume 24, Issue 4, pp 817-826

OBJECTIVE: Contrary to the hypothesis that the racial/ethnic disparity in prostate cancer has a hormonal basis, we did not observe a difference in serum testosterone concentration between non-Hispanic black and white men in the Third National Health and Nutrition Examination Survey (NHANES III), although non-Hispanic black men had a higher estradiol level. Unexpectedly, Mexican–American men had the highest testosterone level. Next, we evaluated whether the same patterns are observed during adolescence, the time of prostate maturation.

METHODS: We measured serum testosterone, estradiol, and sex hormone-binding globulin (SHBG) by immunoassay in 134 males aged 12–19 in NHANES III. Mean concentrations were compared by race/ethnicity adjusting for age, Tanner stage, percent body fat, waist, physical activity, tobacco smoke, and the other hormones.

RESULTS: After multivariable adjustment, in the 12–15-year-old males, testosterone concentration was lower in non-Hispanic blacks than whites (p = 0.043), SHBG concentration did not significantly differ between the two groups. Mexican–Americans had the highest testosterone (versus non-Hispanic black: p = 0.002) and lowest SHBG (versus non-Hispanic white: p = 0.010; versus non-Hispanic black: p = 0.047) concentrations. Estradiol concentration was lower in non-Hispanic blacks (p = 0.11) and Mexican–Americans (p = 0.033) compared with non-Hispanic whites. After multivariable adjustment, in the 16–19-year-old males, testosterone, estradiol, and SHBG concentrations did not differ between non-Hispanic blacks and whites. Mexican–Americans had the highest testosterone concentration (versus non-Hispanic white: p = 0.08), but did not differ from the other groups on estradiol and SHBG concentrations. In both age groups, these patterns were generally present, but less pronounced after adjusting for age and Tanner stage only.

CONCLUSION: In adolescent males, non-Hispanic blacks did not have a higher testosterone concentration than non-Hispanic whites, and Mexican–Americans had the highest testosterone concentration, patterns similar to adult males.

This sample is not large, and some of the statistical adjustments may be questionable. But others have also failed to find black-white differences in testosterone among adolescents in unadjusted NHANES data; nor were they seen in a larger study of adolescents,

Steroid hormones during puberty: racial (black-white) differences in androstenedione and estradiol--the Bogalusa Heart Study.

A large biracial cross-section of 1038 healthy children aged 6-18 yr with 519 blacks, 519 whites, 678 males, and 360 females was evaluated for Tanner stage and serum levels of androstenedione, dehydroepiandrosterone- sulfate, estradiol, progesterone, and testosterone. The anthropometric values of the blacks and whites were very similar at each Tanner stage with only minor differences in age, height, and weight related to an earlier onset of puberty in blacks. The hormones dehydroepiandrosterone- sulfate, progesterone, and testosterone did not exhibit any racial differences. Estradiol showed a significantly higher level among black males compared to white males (P 5 0.05) whereas androstenedione was significantly higher in both white males (P = 0.0001) and females (P I 0.01) compared with blacks.

Y haplogroups and aggression in humans

Greg Cochran writes:
If a new environment favored lower (or higher) aggressiveness in males , a Y-chromosome that induced lower (or higher) aggressiveness would take off. And since different Y chromosomes do indeed affect the level of aggressiveness in mice [which I just found out], possibly by affecting testosterone production – this mechanism is plausible. [. . .]

Fortunately for all concerned, the selective value of aggressiveness, etc. has been the same for all human populations forever and ever, before and after the development of agriculture. Otherwise you might see weirdly rapid expansions of particular Y-chromosome haplogroups – common, yet only a few thousand years old.

A 2009 study of 156 Pakistanis found an association opposite what one might expect, but I doubt it would replicate in a larger sample:
Five Y haplogroups that are commonly found in Eurasia and Pakistan comprised 87% (n=136) of the population sample, with one haplogroup, R1a1, constituting 55% of the sampled population. A comparison of the total and four subscale mean scores across the five common Y haplogroups that were present at a frequency > or =3% in this ethnic group revealed no overall significant differences. However, effect-size comparisons allowed us to detect an association of the haplogroups R2 (Cohen's d statistic=.448-.732) and R1a1 (d=.107-.448) with lower self-reported aggression mean scores in this population.
A PhD thesis published this year ("The Y chromosome in cardiovascular disease") looks at reasonably large samples of Polish men and evidently finds no associations between Y haplogroup and sex hormones or aggression:
Though no analysis of the human Y chromosome has ever been completed in the context of these \male-relateda or \sex-specifica phenotypes, evidence from animal models supports a hypothetical role for the Y chromosome in regulation of both aggression and sex hormones. Firstly, the Y chromosome has been repeatedly implicated in aggression in murine models; Gatewood et al. found that female mice carrying an SRY-deleted Y chromosome had significantly higher aggression levels than wild-type female mice, similar to those found in males (Gatewood et al. 2006). Similarly, the Y chromosome was associated with sex steroids through its function in sex determination (Wilhelm et al. 2007).

To identify the mechanism of association between haplogroup I of the Y chromosome and CAD, the effect of this haplogroup on \sex-associateda and \sex-specifica phenotypes was investigated in a series of experiments highlighted in this chapter. No relationship between the Y chromosome and any facet of aggression or sex steroid was identified. These data indicate that these traits are unlikely to drive the association between haplogroup I and increased predisposition to CAD.

(More interestingly, while I haven't looked at the thesis closely it does apparently confirm in Polish men an association between Y haplogroup I and cardiovascular disease, which I hadn't taken too seriously when it was previously reported in British men.)

Although a lack of convincing evidence that major extant European Y haplogroups are differentially associated with aggression doesn't rule out the possibility that Y chromosomes associated with, e.g., lower aggressiveness constituted a larger share of European male lineages in the past, I doubt this possibility as an explanation for the recent expansion of haplogroups like R1b and R1a.

Testosterone Administration Reduces Lying in Men

From the Plos ONE article:
Testosterone is known to influence brain development and reproductive physiology but also plays an important role in social behavior [4]–[9]. While most studies have investigated a potential association between testosterone and aggressive behavior, two recent studies suggest that testosterone may also increase prosocial behavior or lead to less selfish behavior in certain situations [6], [9]. We therefore investigate a link between testosterone and self-serving lying. A prominent interpretation of the existing evidence on the role of testosterone in social behavior is that the hormone enhances dominance behavior, i.e., behavior intended to gain high social status [6]–[8], [10]–[14], which in humans can be aggressive or prosocial depending on the context. Recent research suggests that pride may have evolved as an affective mechanism for motivating such status seeking behavior [15]. Pride is indirectly linked to status seeking because it is an inward directed emotion that signals high status or ego. It has been speculated that testosterone helps translate such motivation into action, for example, in acts of heroic altruism [16], [17]. Importantly, an effect of testosterone on behavior via pride should also work if behavior cannot be observed by others and an individual’s status in the eyes of the others may therefore not be directly affected. [. . .]

Our main finding is a lower incidence of self-serving lies in the testosterone group. [. . .]

While we can rule out a belief effect we cannot ultimately conclude whether our findings are driven by a direct influence of testosterone on prosocial preferences or via increased status concerns. A potential interpretation for our findings is that testosterone administration affects a concern for self-image [25], or pride [16], i.e., enhances behavior which will make a subject feel proud and leads to the avoidance of behavior considered “cheap” or dishonorable. Subjects in our testosterone group may therefore lie less. This is intriguing because pride could be an affective mechanism underlying a link between testosterone and dominance behavior. An interpretation of our findings in terms of pride is in line with anecdotal and correlational evidence indicating that testosterone plays a positive part in heroic altruism [17]. It is also in line with reports that high testosterone individuals display more disobedient behavior in prison environments where proud individuals may be less willing to follow the strict rules and comply with orders [26], [27]. Finally, a relation between pride, testosterone, and the willingness to engage in “cheap” behavior also fits the observation that the five inmates with the lowest testosterone levels in a sample of 87 female prison inmates were characterized as “sneaky” and “treacherous” by prison staff members [27]. Further experiments manipulating whether lying is an honorable action (e.g., lying for charity) or not (lying for self) are needed to clarify the role of pride in the effect of testosterone on human social behavior. An alternative interpretation of our results, which we cannot rule out, is that testosterone has a direct effect on prosocial behavior, making people more honest per se.

The press release:
The researchers compared the results from the testosterone group to those from the control group. "This showed that the test subjects with the higher testosterone levels had clearly lied less frequently than untreated test subjects," reports the economist Prof. Dr. Armin Falk, who is one of the CENS co-directors with Prof. Weber. "This result clearly contradicts the one-dimensional approach that testosterone results in anti-social behavior." He added that it is likely that the hormone increases pride and the need to develop a positive self-image. "Against this background, a few euros are obviously not a sufficient incentive to jeopardize one's feeling of self-worth," Prof. Falk reckons.

Update on Androgen Receptor gene

An Encore for the Repeats: New Insights into an Old Genetic Variant
It is commonly accepted that the length of the polyQ tract influences the transactivation capacity of the receptor in an inverse manner; that is, the longer the tract, the lower the activity. To support this hypothesis, a clear negative impact on AR activity is documented in relationship with pathological expansions of the repeat length (40 or more), known as the Kennedy syndrome (5). This syndrome is characterized by spinobulbar muscular atrophy and hypoandrogenism due to partial androgen insensitivity. On the other hand, controversies still exist about the effect of variations in polyQ within the normal polymorphic range. The normal distribution of the (CAG)n is reported as 6–39 repeats, with a median of 21–22 in White Caucasian, 19–20 in African-American, 22–23 in Asian, and 23 in Hispanic populations. Clinical observations showing a linear correlation between testosterone level and CAG repeat length support the notion of a functional effect of the polymorphism within the normal range. In fact, increased circulating testosterone and estradiol levels in men with a higher number of CAG repeats can be considered as a compensatory mechanism aimed to overcome the weaker AR activity (6, 7). However, such a linear correlation has not been clearly demonstrated by in vitro experiments. The first two functional studies reported that the longest tract (Q31) displayed lower activity when compared with the shortest one (Q15). However, no significant differences were observed by comparing these two types of alleles to an intermediate number of CAG repeats (20 or 24) (8, 9). Quite strikingly, two recent articles provided evidence for the lack of a stepwise reduction in activity with increasing CAG length across the polymorphic range (10, 11). The reporter gene assay with three different CAG lengths (16, 22, and 28) has indeed shown the highest AR activity in the presence of 22 CAG repeats(10). The other study, performed in a human prostate tumor cell model, has provided mechanistic insights into how both increased and decreased polyQ allele length may negatively affect receptor function (11). This study has revealed a critical polyglutamine size (Q16-Q29) for optimal androgen-induced AR signaling, which corresponds to 91–99% of AR alleles within different ethnic groups. These novel in vitro findings have introduced a new concept for the analysis of AR-CAG repeat length in relationship to AR-related diseases, indicating that linear regression models are likely to be inappropriate.

The study by Davis-Dao et al. (12) indicates a disadvantage only in the case of short CAG repeats; however, upcoming investigations will probably shed light on whether the “optimal range” hypothesis can be applied also to this specific pathological context. In fact, the stratified analysis of nearly 4000 subjects, included in articles dealing with male infertility and AR-CAG length, has provided clinical evidence for the potential benefit of a CAG range corresponding to 22–23 triplets in spermatogenesis (24). However, it must be taken into consideration that this specific range may not be the same across different ethnic groups and may even vary in different tissues because the effect of polyQ repeat on transactivation is cell specific, presumably due to distinct profiles of coregulator proteins (11). Moreover, it is possible that spermatogenesis, more than the process of testis descent, depends predominantly on the genomic action of androgens, and thus on the direct consequence of the CAG length on transactivation. Clearly, more functional studies are needed for the interpretation of clinical data in different types of androgen-dependent diseases.

That blacks average fewer AR-CAG repeats has been held up as evidence blacks are more "masculinized". I was unconvinced one could draw that conclusion even accepting an inverse relationship between CAG repeat length and AR activity (since the CAG repeat represents only one link in androgen-related pathways, and there may be any number of other racial differences in relevant genes). Now it appears that compared to blacks, whites may in fact be more likely to have "optimal" CAG repeat lengths.

In addition, variation in another polymorphism of the AR gene, GGN repeat length, could conceivably lower AR activity in blacks relative to whites:

Short GGN repeats seem to be associated with decreased semen volume, possibly due to suboptimal AR activity. ["Androgen receptor gene GGN repeat length and reproductive characteristics in young Swedish men"]

Contrary to previously published data from Caucasians and Asian populations, which have the 2 by far most common GGN alleles of 23 and 24 in the former, and 21 and 22 in the latter, we found 4 common alleles of 20, 21, 22, and 23 in our study population with the highest frequency of 20 GGN allele followed by 22, 21 and 23 (GGN)n (Fig. 2). ["Androgen receptor gene CAG and GGN polymorphisms in infertile Nigerian men"]

Some more background from the first article above:

Throughout the human genome there are trinucleotide repeat sequences susceptible to either expansion or contraction during replication, giving rise to length polymorphisms in the general population. The polymorphic CAG repeat, which encodes an uninterrupted polyglutamine (polyQ) tract in the N-terminal transactivation domain of the androgen receptor (AR), is the most extensively studied genetic variant in individuals with disorders of the male reproductive system.

Despite an impressive number of studies, the pathogenic role of this polymorphism and its clinical relevance are still a matter of debate. Although a recent meta-analysis of 33 publications (1) supports a pathogenetic role for longer polyQ length in male infertility, the authors conclude their work stating that there is a need for new, well-designed studies (1). In fact, available data do not allow us to establish what range of AR-CAG repeat lengths predisposes impaired sperm production or to estimate the entity of the associated risk (1). Similar to other genetic variants, the literature related to CAG repeats suffers from an abundance in conflicting case-control association studies and a paucity of functional data (2). There are several plausible explanations for these apparent controversies, mostly related to: 1) poor study design (inappropriate selection of patients and controls, particularly with respect to their phenotype and their ethnic/geographic origin, and underpowered size of the study population); and 2) intrinsic complexity of the interaction between the AR and its endogenous/environmental ligands. An additional intricacy derives from the presence of another polymorphic trinucleotide repeat, (GGN)n, in the first exon of the AR gene, which may modulate the functional effect of the CAG repeat length, stressing the need for a combined analysis of the two AR polymorphisms (3, 4).

Men With Wider Faces Are More Generous to Their In-Group When Out-Group Competition Is Salient

Face Structure Predicts Cooperation: Men With Wider Faces Are More Generous to Their In-Group When Out-Group Competition Is Salient (abstract):

Male facial width-to-height ratio appears to correlate with antisocial tendencies, such as aggression, exploitation, cheating, and deception. We present evidence that male facial width-to-height ratio is also associated with a stereotypically male prosocial tendency: to increase cooperation with other in-group members during intergroup competition. We found that men who had wider faces, compared with men who had narrower faces, showed more self-sacrificing cooperation to help their group members when there was competition with another group. We propose that this finding makes sense given the evolutionary functions of social helpfulness and aggression.

Masculinity, skin color, and male facial attractiveness

Does Masculinity Matter? The Contribution of Masculine Face Shape to Male Attractiveness in Humans (PLoS ONE):
The proposal [. . .] that masculine men are immunocompetent and attractive – underpins a large literature on facial masculinity preferences. Recently, theoretical models have suggested that current condition may be a better index of mate value than past immunocompetence. This is particularly likely in populations where pathogenic fluctuation is fast relative to host life history. As life history is slow in humans, there is reason to expect that, among humans, condition-dependent traits might contribute more to attractiveness than relatively stable traits such as masculinity. [. . .]

The relationship between masculinity and attractiveness was assessed in two samples of male faces. Most previous research has assessed masculinity either with subjective ratings or with simple anatomical measures. Here, we used geometric morphometric techniques to assess facial masculinity, generating a morphological masculinity measure based on a discriminant function that correctly classified >96% faces as male or female. When assessed using this measure, there was no relationship between morphological masculinity and rated attractiveness. In contrast, skin colour – a fluctuating, condition-dependent cue – was a significant predictor of attractiveness.
The authors point out problems with attempts to assess the affect of masculinity on facial attractiveness that rely on human ratings of perceived masculinity or digital manipulation of photographs: (1) for rated masculinity, "subjective judgments of masculinity are based on factors other than just morphological masculinity"; (2) with morphing techniques, factors potentially more important than masculinity in determining real world attractiveness are not allowed to vary, and a preference for averageness might result in participants systematically preferring more or less masculine morphs even if women are completely indifferent to masculinity. As for the effects of skin color, in this sample:
The regression retained only skin yellowness as a predictor of attractiveness, and the effect of skin yellowness was positive and highly significant (F(1,71) = 10.806, Beta = .366, t = 3.287, p<.002). Skin lightness, redness and morphological masculinity did not significantly predict attractiveness (all p>.114, see Table 1).
Other studies have also found increased skin lightness and redness associated with perceived health and attractiveness. The association of yellowness with attractiveness "may be attributable to dietary carotenoid deposition in the skin. This suggests that carotenoids, which are involved in health signaling (Massaro et al. 2003; Saks et al. 2003) and sexual selection (Eley 1991; MacDougall and Montgomerie 2003; Massaro et al. 2003) in many species of birds and fish, may also affect the appearance of health in humans."

Race and physical attraction

A commenter links to a 2007 neuropolitics.org post ("Who Are The Caucasians Attracted To? Politics, Religion, and Physical Attraction") that reports the following survey results. As expected, "white females were more attracted to whites than are white males".

Performance enhancing effects of HGH and Test

A modest dose (two milligrams per day) of growth hormone is associated with a 3.9% boost in sprint capacity, which researchers estimate translates to shaving 0.4 seconds off a 100m time. Sprint capacity in men receiving both growth hormone and 250 milligrams per week of testosterone increased by an average of 8.3%. Thankfully our American negro athletes (and Jamaicans) don't need to resort to this sort of cheating. (Link via Randall Parker.)

Black-white differences in digit ratio during prenatal development

An exhibit from the 1921 second international congress of eugenics shows black-white 2d:4d differences established by the third month of gestation [1].
While this bit of evidence does not definitively rule out involvement of androgens in the black-white divergence in digit ratio, it certainly does nothing to quell my doubts about the meaningfulness of cross-racial comparisons of digit ratio for inferring cross-racial differences in prenatal testosterone exposure. The critical windows of androgen exposure for developing males seem to come with mid-gestational and postnatal surges of testosterone to near-adult levels [2]. I'm inclined to believe, rather, black-white differences in digit ratio are due largely if not entirely to genetic factors unconnected to prenatal androgenization. On an entirely unrelated note, a caption above reads:
The hand is relatively broader and slightly shorter and the thumb relatively longer in the white fetus than in the negro fetus
Coincidentally, according to the second source I cite above (a review article from 2006):
Non-human apes and brachiating monkeys have shorter thumbs and longer fingers, and also lower 2D:4D.
Other differences reported in the 1921 study include smaller brain case and higher frequency of evolution toe in black fetuses (continue reading).