Inductivist

The General Social Survey rated the skin darkness of a sample of black Americans, ranging from "very dark brown" to "very light brown." Biologically oriented researchers might see the question as a rough measure of the percentage of European ancestry, while sociologists would see it as a measure of discrimination--lighter-skinned blacks getting better treatment. Respondents were also given a job prestige score that ranges from 16 to 80--16 is a shoeshine and 80 is a physician. Here are the job prestige means listed by skin tone:

You can see that average job prestige tends to rise with lighter skin. The mean for blacks with "very light brown" skin is roughly two-thirds of a standard deviation higher than the mean for "very dark skin" blacks. 

The pattern can be interpreted in at least two ways: 1) genetic--blacks with more European ancestry tend to rise in the status hierarchy much more than African blacks, or 2) sociological--whites discriminate more against darker blacks, and perhaps light-skinned blacks have white (privileged) relatives who gave them advantages. 

For several reasons, I'm inclined toward the genetic explanation. For one, my experience is that when a white person is interacting with a black person, his thought is, "I'm talking with a black person," not, "I'm talking with a light-skinned black person." For another, how do those Nigerian immigrants do so well in the US when their skin tends to be so dark? The sociologist would predict severe discrimination. The biologist would argue that African immigrants are a select group of Africans--above average in IQ and drive--and this overwhelms any bias they might experience. 

 According to conventional economic theory, growing up in a large family predicts less income as an adult because parents were unable to invest as much in each child. By contrast, genetic theory would predict that that family size would not matter for how much income you earn as an adult; rather, income would be predicted by one's IQ. Let's test these two competing hypotheses using General Social Survey data. 

Respondents were asked how much income they earned in the past year, and they were also given a ten-word vocabulary quiz, which makes a decent proxy for IQ (N = 19,902).

This table shows the estimates for a regression model that includes personal income in constant dollars as the dependent variable and the number of siblings as the predictor. You can see that each additional sibling results in a predicted reduction in one's income of $1,139.  (I believe these are 1986 dollars.)

Looking at this table above, we can see that IQ is positively related to income, and the beta indicates that the relationship is of considerable magnitude. It is predicted that each additional IQ point will result in an additional $423 in income. 

The unstandardized coefficient for number of siblings has dropped from $1,139 down to only $586. In other words, much of the reason why a large family predicts a smaller income is due to the correlation between having many siblings and having a lower IQ. This finding supports, to some extent, the genetic hypothesis. On the other hand, we see that the sibling coefficient is still statistically significant, so even after controlling the influence of IQ, the number of siblings is still negatively correlated with income. The economic hypothesis appears to have something to it. 

 

A small percent of whites have an allele that is associated with hemochromatosis--a hereditary disorder in which iron salts are deposited in the tissues, leading to liver damage, diabetes mellitus, and bronze discoloration of the skin.  This polymorphism is completely absent in West African blacks.  This is the kind of difference race deniers tell us doesn't happen. 

In this new study, researchers estimated the European ancestry of African Americans using the frequency of this hemochromatosis allele. 

They found that, indeed, the frequency of the allele is 0.00000 in people from the Gambia, Nigeria, Senegal, and Sierra Leone. The frequency in white Americans was 0.060-0.067. For all black Americans it was 0.012.

The average white ancestry for black Americans was 0.180 for the whole sample, but it differed by city:

Proportion white ancestry

Rochester, NY   0.132

Birmingham, AL   0.146

Upper Savannah Region, SC   0.157

Portland, OR   0.161

San Diego, CA   0.175

Hartford, CT  0.178

District of Columbia   0.196

Oakland, CA   0.238

Irvine, CA   0.243

The proportion white of blacks living in Irvine is 1.8 times higher than for those living in Rochester, NY, so the variation is noteworthy. I don't see a clear regional pattern here. 

The authors report that their findings are consistent with studies using other methods. They also found both paternal and maternal contributions of white American ancestry in black Americans.

New from Scientific Reports

Abstract

Attention-defcit/hyperactivity disorder (ADHD) is an impairing neurodevelopmental condition highly prevalent in current populations. Several hypotheses have been proposed to explain this paradox, mainly in the context of the Paleolithic versus Neolithic cultural shift but especially within the framework of the mismatch theory. This theory elaborates on how a particular trait once favoured in an ancient environment might become maladaptive upon environmental changes. However, given the lack of genomic data available for ADHD, these theories have not been empirically tested.

We took advantage of the largest GWAS meta-analysis available for this disorder consisting of over 20,000 individuals diagnosed with ADHD and 35,000 controls, to assess the evolution of ADHD-associated alleles in European populations using archaic, ancient and modern human samples. We also included Approximate Bayesian computation coupled with deep learning analyses and singleton density scores to detect human adaptation.

Our analyses indicate that ADHD-associated alleles are enriched in loss of function intolerant genes, supporting the role of selective pressures in this early-onset phenotype. Furthermore, we observed that the frequency of variants associated with ADHD has steadily decreased since Paleolithic times, particularly in Paleolithic European populations compared to samples from the Neolithic Fertile Crescent.

We demonstrate this trend cannot be explained by African admixture nor Neanderthal introgression, since introgressed Neanderthal alleles are enriched in ADHD risk variants. All analyses performed support the presence of long-standing selective pressures acting against ADHD associated alleles until recent times. Overall, our results are compatible with the mismatch theory for ADHD but suggest a much older time frame for the evolution of ADHD-associated alleles compared to previous hypotheses.

Methods

Results

Abstract from the journal Genes:

Investigations on the impact of genetic factors on the development of obesity have been limited regarding the Roma population—the largest and most vulnerable ethnic minority in Europe of Asian origin. Genetic variants identified from genetic association studies are primarily from European populations.

With that in mind, we investigated the applicability of data on selected obesity‐related single nucleotide polymorphisms (SNPs), obtained from the Hungarian general (HG) population of European origin, on the Hungarian Roma (HR) population.

Twenty preselected SNPs in susceptible alleles, known to be significantly associated with obesity‐related phenotypes, were used to estimate the effect of these SNPs on body mass index (BMI) and waist circumference (WC) in HG (N = 1783) and HR (N = 1225) populations. Single SNP associations were tested using linear and logistic regression models, adjusted for known covariates.

Out of 20 SNPs, four located in FTO (rs1121980, rs1558902, rs9939609, and rs9941349) showed strong association with BMI and WC as continuous variables in both samples. Computations based on Adult Treatment Panel III (ATPIII) and the International Diabetes Federation’s (IDF) European and Asian criteria showed rs9941349 in FTO to be associated only with WC among both populations, and two SNPs (rs2867125, rs6548238) in TMEM18 associated with WC only in HG population. A substantial difference (both in direction and effect size) was observed only in the case of rs1801282 in PPARγ on WC as a continuous outcome.

Findings suggest that genetic risk scores based on counting SNPs with relatively high effect sizes, defined based on populations with European ancestry, can sufficiently allow estimation of genetic susceptibility for Roma. Further studies are needed to clarify the role of SNP(s) with protective effect(s).

Abstract

Introduction: In the U.S., asthma disproportionately affects urban minority populations, with Puerto Ricans showing the highest asthma prevalence 16.1%. However, what causes high asthma
prevalence among the Puerto Ricans is not very well understood. The varying proportions of African, European, and Native American genetic ancestry in Puerto Ricans can be leveraged to identify genetic determinants of clinically significant measures and outcomes such as lung function and asthma severity. We have previously demonstrated that genetic ancestry is associated with lung function.

Methods: In this current study, we sought to discover potential causal genes that may be associated with lung function in Puerto Rican islanders by applying admixture and fine mapping methods. A genome-wide admixture mapping study of lung function was conducted in 841 Puerto Rican children with and without asthma, who were recruited from Puerto Rico. After mapping admixture segments, we fine-mapped the genomic region using whole genome sequencing data. RNA-seq and eQTL mapping were used to elucidate underlying biologic links between genetic variants and lung function.

Results: The association test between local genetic ancestry and forced expiratory volume in 1 second (FEV1) identified a strong admixture mapping peak on chromosome 1q32, indicating that each African ancestry allele was associated with a 0.13 liter decrease in the volume of exhaled air [95%CI: -0.08 to -0.18, p-value=4.90×10-8]. Three variants identified from the fine-mapping analysis were eQTL of TMEM9 gene in nasal epithelial cell. The minor allele of the variant associated with TMEM9 gene (rs10920079) tracked with African ancestry and was associated with significantly decreased lung function and TMEM9 gene expression. TMEM9 was inversely correlated with proinflammatory cytokine IL-6 and IL-1β gene expressions.

Conclusion: The results from admixture mapping discovered variants that were associated with decreased lung function. Functional annotation and validation with RNA-seq and eQTL mapping indicate that these SNPs may be involved with regulating cytokine production, which may influence the lung function of Puerto Ricans.

You know a social problem becomes serious and legit when we discover--and only when we discover--that it is hitting blacks disproportionately. Brain cancer--not a major problem.  It hits whites worse.

Now that we see that WuFlu is bad in black communities, we get the same old lament about omnipresent anti-black racism. Heck, you'll see it on Fox about as much as anywhere. The American people can never hear enough that disease is colorblind... but we are not.

Let's see what actual scientific research has to say about one of the conditions putting you at risk of Covid-19, diabetes:

The risk of type 2 diabetes is twice as high for blacks as whites, even after adjusting for  socioeconomic status (SES). This suggests that genetic factors may help explain the racial gap.

The researchers in the linked study conducted an admixture analysis using 2,189 ancestry-informative markers in 7,021 African Americans. The group that was highest in African ancestry was 1.3 times more likely to have diabetes than the lowest ancestry group. This was true after adjustment for age, sex, body mass index (BMI), and SES.

Race is genetic, and it matters, people. But you'll never hear that on Fox.


(Hat tip to Greg Cochran on the article.)

This new study on ancestry and cognitive ability by Jordan Lasker and team blew my mind.  If NN Taleb is right that IQ research is crap, then all other social science is complete shit.  Ever since I read Arthur Jensen's g Factor in 1998, I've been damned impressed by the quality of general intelligence research. I believe George Bernard Shaw said that Das Kapital made a man out of him. g Factor made a man out of me.

Jensen and Phil Rushton, vilified forever by Leftists, predicted that between 50 and 80% of the black-white gap in general intelligence was due to genetic differences. The Lefties predicted that genes explain none of the gap.

Lasker et al's study examined thousands of SNPs (DNA points) for thousands of blacks, whites, and biracials, and found that percent European ancestry explains 50-70% of the racial gap. Jensen and Rushton win, the feel-good researchers lose.

The Lefties also argued that skin color is a measure of how much a person is discriminated against, and discrimination explains the racial gap in IQ. Jensen and Rushton predicted that discrimination would not be an important cause of the difference.

Lasker and team found that skin color (discrimination) explained very little of the racial gap. Again, Jensen/Rushton emerge as the real scientists--the people whose predictions come true.

This study has moved my view on the racial gap from "probably mostly genetic" to "almost certainly mostly genetic."

Lance Welton at Unz.com does a nice job of summarizing Richard Lynn's brand new book Race Differences in Psychopathic Personality

I won't repeat Lance's points, but I see in the comments that some people are claiming that the racial differences are explained in terms of the environment. This, of course, is the standard explanation--the only one you will get in sociology class, if the instructor is honest enough to acknowledge that the group differences indeed exist.

There are two obvious reasons to think the racial gaps (psychopathy running from high to low in this order: black, Native American, Hispanic, white, Asian) are at least partially due to genetic differences: 1) the differences are basically universal–found historically (Lynn cites over 700 studies conducted from the 19th century to now) and all around the world, and 2) psychopathy is highly heritable, similar to general intelligence. Therapists find it practically impossible to treat.

As Arthur Jensen explained, it is reasonable to conclude that if genes explain 70% of the variation in a trait, they likely explain 70% of group differences. The only reason why the commonsense belief that “What You See is What You Get” is not popular today but “People Are Not Themselves But Their Surroundings” is assumed to be true is that we have been propagandized by armies of full-time storytellers for more than a century.

I do take issue with conceptualizing psychopathy as a disorder, as if human nature is naturally good, and antisociality suggests a brain that is not working properly. I’m not criticizing Lynn but psychiatry. Exploitativeness is a regrettable but perfectly healthy and natural supertrait.  Psychiatrists want to turn all problematic behaviors into forms of mental illness, which is just silly. Evolution has designed us to thrive and to be strong, not to be burdened on every side by illness and weakness.  Mainstream behavioral science portrays us--the descendants of nature's winners--as naturally frail.  Complete BS.

In the last post, General Social Survey data indicated that researcher Paul Dolan was wrong in claiming that single, childless women are happier than married women with kids.  In the old days, I would have focused, at least some, on the Durkheimian idea that social roles shape characteristics like one's level of happiness.  I was trained as a sociologist, and it has been my instinct to see social forces as important.

Years of study have convinced me that it is time to focus more on biological forces. The correlation between marriage and well-being need not be causal: people who are genetically happy might simply select themselves into marriage.  In fact, the correlations between marriage and a host of positives--greater financial success, mental and physical health, lower mortality, less risky behavior, less crime, and longer longevity--might be due to common genes which cause the correlations.

A study by Johnson et al. (2004) supports this idea.  Analyzing data on a sample of over 7,000 adults that included more than 2,500 twin pairs, they found that certain heritable traits predict marriage, and that much of the link between being married and being happy is due to genes. 

Specifically, they found the following traits for married versus single women: married women are more affectionate, nervous, careful, and traditional, and they feel like they are treated fairly by others. On the flip side, single women are less sociable, more risk-taking; they're calmer, more modern, and they think they are treated unjustly by others.

The profile of married men versus single men is very different: married men are cheerful, active, persistent, decisive, persuasive, aggressive, and traditional. They are less prone to fantasy, and they think that people treat them fairly.  Single men tend to be the opposite: They are sullen, indecisive, undisciplined, passive, modern, prone to fantasy, and they feel they are treated unfairly. 

All of these traits are strongly influenced by genes. According to the study, the heritability of being married is about .7, meaning that 70% of whether or not people are married is due to variation in genes.

So it looks like married people, especially men, tend to be happier because of their personalities. Affectionate, sociable women seek out marriage, and so do cheerful men who have the traits that lead to career success.  Married women seem drawn to comfort, security, and affection.  Men, in general, appear to be drawn to marriage, and the success-bound ones achieve it.

Single men and women are more modern, so they probably see marriage as less desirable, less expected, and both tend to be disagreeable. Single men might be less happy because they are less successful, and single women are more alienated, which is associated with sadness and mental health issues.  In addition, single women are risk-takers, and seem less drawn to the security and comfort of a permanent union.   

Authors of a paper published earlier this year in Behavior Genetics have made arguments similar to those of  HBD writers Greg Cochran and JayMan: psychological traits are basically the result of 1) genes, and 2) noise. 

Years ago, behavioral geneticists discovered that the environments shared by siblings have little impact on how you turn out. By contrast, the environment you experience that is unique to you appeared to be about as important as genes -- both of them explaining roughly half of the story.   

The authors, two Russians from St. Petersburg University (they're Russians, so they must be evil) explain that research trying to identify specific factors from the unique environment that are important has been mostly unsuccessful.  Factors like illnesses and accidents typically explain less than 3% of the examined traits.

In addition, genetic research (mostly experiments on animals) has shown that traits depend a great deal on stochasticity--a fancy term for randomness, or "luck."  For instance, ultraviolet rays increase genetic mutation rates in organisms, but exactly which genes will be affected is a stochastic process. Random genetic errors that occur in the early stages of embryonic development will be more consequential; in this case, all the descendants of the initial mutant cell will also be mutant. 

Complex organic systems like the human body or brain are especially likely to be shaped by random events. For example, in female embryos, one of the two X-chromosomes is inactivated as a Barr body.  Each cell will make a random 'decision' which X-chromosome (the paternal or maternal) gets inactivated, and the 'decision' is maintained in subsequent cell divisions.  As a result, the female becomes mosaic.  In heterozygous females with the EDA mutation, you get ectodermal dysplasia which leads to an absence of perspiratory glands.  Depending on what X-chromosome is active, some skin areas are defective in sweating, while other areas are normal. The mosaicism is random.  Even identical twins raised in very similar environments will differ significantly.

Another human example is the growth of synapses in the developing brain.  While the number and locations of these connections are under some genetic control, research has demonstrated a significant stochastic component.  So again, identical twins raised the same will end up with brain wirings that are somewhat different, this is simply due to random differences in development, and it can cause behavioral differences.

These authors do not mean that these random factors are actually causal factors that simply have not been identified yet. They are claiming that pure randomness is simply a key part of our development, and the hard determinist view is simply incorrect.

They don't touch the political implications of all this, but I'll jump in.  To summarize, it's only a little bit of a simplification to say that we may be the product of genes and random events.  Genetic research is also telling us that hundreds or thousands of genes influence a trait, but each only a trivial bit, so simple pathways for intervention and improvement might be hard to find.  And you can't control randomness, so there seem to be fewer and fewer possibilities for government to step in and effectively address social problems -- at least in ways acceptable to liberals.  The old-time conservative who contended that human nature is tragically flawed and that one must resign oneself to human limitation seems more and more like a prescient, wise person.     

Look at this graph (GSS data) which shows the mean number of children that gay men ages 40-64 have for the past four decades:
















In the 80s, the average gay man had two kids.  By the 90s, the number had dropped to .81, and in this decade, it's down to .58.  In other words, a gay man 40 years wasn't that different than a straight guy in terms of offspring. Now, he has less than 30% the family size of a heterosexual.

While Greg Cochran is right that the heritability of homosexuality is not high, there seems to be some genetic influence, so it's ironic that gay liberation is leading to fewer people with genes that raise the odds of homosexuality.  That implies fewer and fewer gay men in the future.  Strange, but I don't hear anyone accusing liberals of secretly pushing for the slow genocide of homosexuals. 

In the last post, we looked at ethnic differences in whether the environment or genes are thought to be more important for a variety of traits. Now let's see which factors predict choosing nurture over nature.

Using GSS data, I estimated linear regression models (OLS) with each of the four questions as dependent variables, plus a scale of all four of them summed.  I included all demographic predictors I could think of, including: sex, age, race, southern region, immigrant vs. native-born,  educational level, income, church attendance, number of children, and political orientation. I list below the significant effects (beta weights are shown):

Obesity
Black  -.15
Education  .10

So blacks, compared to whites, and less educated people think environment is less important. Race is the more powerful predictor.

Alcohol Abuse
Female  -.08
Education  .07

Females and the less educated think genes are more important for alcohol abuse.

Altruism
Female  -.06
Black  -.06

Women and blacks are shifted toward seeing genes as important for altruism.

Athleticism
Education  .06
South  -.07

For athletic ability, Southerners and the less educated tend to see genes as being more important.

Nurture over nature scale
Black  -.11
Education  .11

When the scores for all four questions are added together to make a scale, blacks and the less education are shifted toward genes having the most impact.

Not surprisingly, people exposed to more education tend to believe in the power of the environment. After years of getting the same message from liberal teachers, what do you expect?  It is a surprise, though, that blacks, after adjusting for education, give higher estimates to the power of genes.

UPDATE: It might surprise you that political orientation (liberal vs. conservative) is unrelated to one's view of the importance of genes. 

UPDATE II: I wonder if the race difference comes from the fact that blacks are more fatalistic than whites, and people tend to assume (wrongly in my view) that genes imply determinism but environment does not. Whites might embrace nurturism because it sounds compatible with the idea that we can take control of our lives and improve things.  

Do Americans think people act like they do because of environment or genes?  The General Social Survey gave respondents four scenarios:

1) Carol is a substantially overweight White woman. She has lost weight in the past but always gains it back again.

2) David is an Asian man who drinks enough alcohol to become drunk several times a week. Often he can't remember what happened during these drinking episodes.

3) Felicia is a very kind Hispanic woman. She never has anything bad to say about anybody, and can be counted on to help others.

4) George is a Black man who's a good all-around athlete. He was on the high school varsity swim team and still works out five times a week.

Respondents were asked to estimate the influences of environment versus genes for each scenario. Answers ranged from 100% genes (scored as a 1) to 100% environment (scored as a 21). 50/50 would be scored as an 11.

I summed the scores for these four questions, and list the means for ethnic groups below (sample size = 1,842):

Mean environmentalism score

Asian Indians  56.7
Scottish  54.9
Czech  52.6
Italy  52.1 
Filipinos  50.9
American Indians  50.9 
Norwegians  50.9
Russians  50.4
Chinese  50.2
Polish  50.1
English/Welsh  49.9
Jewish 49.4
Irish  49.3

All Americans  49.3

German 49.0
Dutch  47.9
Swedish  47.3
Mexican  47.1
Puerto Ricans  46.3
Danish  46.1
Blacks 45.2
French  44.2
Spanish  43.9

The mean score for all Americans indicates that the average person thinks the traits described are 55% due to environmental influences, and 45% due to genes.  This is not far from the truth as indicated by genetic research. Americans seem to be ignoring their environment-is-all social science teachers. On the other hand, I'm sure by "environment" most people are thinking of experiences which siblings share -- families, schools, etc -- but research clearly shows that these factors are not important.

The highest scoring group, Asian Indians, thinks the traits are roughly 65% environment.  The lowest group, people of Spanish descent, put the estimate at about 50/50.  Hispanics, in general, tend to think genes are more important than other groups. This tendency is also true for blacks, but other non-whites -- Chinese, Filipinos, Asian Indians, and American Indians -- think the environment is more important.  It's surprising that several poor minority groups think genes are so important.  The gap between Asian Indians and the Spanish is eight-tenths of a standard deviation -- a large difference.

This new study looked to see if polygenic scores for educational attainment that have been developed from samples of white people work for blacks (sample size = 1,050). A polygenic score sums up how many variations in locations on genes a person possesses that have been correlated with the outcome variable, weighted for the strength of the relationships. In plain English, the higher your score, the higher your genetic risk.

The researchers found that, even though blacks have a genetic history that is very different than whites, the polygenic scores that were developed for whites significantly predicted going to college among blacks. While scores did not predict reading achievement, they did predict math achievement.

Bottom line: genes matter. They matter for whites, they matter for blacks.   

Since 1972, General Social Survey participants have been asked the following question: "Consider a person who believes that Blacks are genetically inferior. If such a person wanted to make a speech in your community claiming that Blacks are inferior, should he be allowed to speak, or not?"

There are positive correlations between IQ and both longevity and height.  Many genes underlie these traits -- it looks like there are health-promoting genes that manifest themselves not only through a long life but perhaps a better functioning brain and ending up taller. And a smart/tall/long-lived person might also have a comparatively small number of mutations that work against health.

Does being an athlete fit in with the rest of these traits?  One might expect height and athleticism to be correlated simply because popular sports like basketball and football favor bigger people.  How about IQ and being a good athlete?  Here are the correlations for IQ and self-rated athletic ability (GSS):

White males (n = 440)   -.05
White females (n = 553)  .01
Black males (n = 74)  -.09
Black females (n = 103)  -.14

For all demographic groups, IQ and athletic ability are either not correlated or a negatively correlated. It does not appear to be the case that there are genes that promote both at the same time (or that subtract from both simultaneously).

One study of athletic performance put heritability at .66.  In plain English, two-thirds of the differences in athletic ability are explained by genetic differences.

General Social Survey participants were asked to rate how athletic they are on a scale from 1 to 5.  I calculated the means for sex and race combinations (N = 2,373):
















Black men rate themselves as most athletic with a mean of 3.57.  White women (2.58) and women of some other race (2.56) come in at the bottom.  The gap between black men and other-race women is nine-tenths of a standard deviation (SD) -- a big difference.

If we focus on just men, the black-white difference is one-third of an SD -- a small advantage for black men.

The biggest within-race gap is among blacks: the male advantage over females is three-quarters of an SD.  The graph doesn't show the overall sex difference: it's over half of an SD.

While it's difficult to rate oneself objectively, these self-ratings seem to have some validity.

Three times in a row (for Hispanics, whites, and Asian Indians), I've shown that the lighter skinned members of a group tend to be smarter than darker members.

I now find the same pattern for a small sample of East Asians born in the US (n = 24). The correlation between darkness and IQ (based on a vocabulary test) is -.16 -- a small effect.

Note: A potential confound occurs to me. Do lower IQ people spend more time in the sun?  With larger samples, it might make sense to look at the sexes specifically.  Lower IQ men might work outside more, but I wouldn't expect this for low IQ women.