Genetic Similarity Theory states that we seek out similar others in order to give our genes the best chance to produce copies of themselves. As Richard Dawkins says in The Selfish Gene, it is genes that survive to the next generation with more copies being found in siblings and related co-ethnics. Therefore, the theory goes, by benefitting genetically similar others, we are benefitting copies of our genes. Speed daters match on genotype, which shows evidence for ability to detect genetically similar others. On a subconscious level, we have the ability to detect genetically similar others.
Assortative mating is a form of sexual selection in which those with similar genotypes and phenotypes mate with each other more often than in would be expected under a random breeding model. One of the numerous ways we match by genetic similarity is phenotype. If the phenotype is similar, more often than not, the genotype is as well. This is what drives friendships and marriages, as well as being the cause for ethnocentrism.
Rushton (1987) showed that humans are able to detect degrees of genetic similarity in others, and prefer those most similar to themselves for friends and spouses than less genetically similar individuals, which is the basis for ethnocentrism. A husband and wife are, on average, as close as fourth cousins. Due to matching by GST, spouses should also match on heritable traits such as IQ, body measurements and personality traits. As McCrae et al (2008) write:
Altruism, Modesty, and Tender-Mindedness are characteristics that most people desire in a spouse (cf. Buss, 1986), but people are most likely to find a mate with these characteristics if they have them themselves. This is an instance of the principle that people with desirable qualities have more options in seeking a desirable mate. At the same time, it seems likely that there is a sense in which disagreeable people may actually prefer the company of their own kind, like the haughty Duke in Robert Browning’s “My Last Duchess,” who disposed of his wife because she was too indiscriminately nice.
Everyone has the perfect spouse in their head that they dream of. However, the type of spouse we end up with will, more often than not, be genetically similar to ourselves. Even spouses who are not of the same race or ethnicity match up on heritable traits such as The Big Five, IQ and physiological measurements.
Divorce is also influenced by genetic factors. Jockin, Mcgue and Lykken (1996) found that 40 percent of the variability in the heritability of divorce comes from genetic factors that affect the personality of one spouse. Traditionalism, extraversion and neuroticism (2 of the Big 5 Personality Traits) are causes for divorce. A few reasons I can think of for neuroticism and extraversion being personality traits correlated with divorce is highly neurotic people are more likely to be stressed, anxious, have hypochondria (the worry of contracting an illness) and obsessive behavior. This can put extra strain on a marriage, leading to both of the spouses not being happy in their marriage, leading to divorce. With extraversion, more extraverted people are more open to meeting others and are more social and talkative. This will lead to feelings of jealousy, causing a strain on the marriage.
The genetic and environmental influences responsible for marriage are different from those that are responsible for divorce. Evidence exists that after mate selection, there may be some protective factors for the couple, such as religion. While other factors that place couples at risk for divorce, such as alcoholism, are also genetic in nature.
Trumbetta and Gottesman (2000) suggested endophenotypes with one being oriented to pair bonding and the other to mate diversification. Pair bonding, obviously, leads to a happier marriage as both spouses are monogamous, whereas mate diversification is associated with multiple marriages. It sounds to me like those who pair bond are more introverted whereas those who have diversity in marriage partners are more extraverted, leading to high divorce rates due to jealousy and cheating. The conclude that there are significant genetic influences on both endophenotypes with unique environmental factors accounting for the rest of the variance,
Spouses, as well as friends, sort on characterisitics such as race, socioeconomics, physical attractiveness, level of education, family size and structure, IQ and longevity. This is the Selfish Gene in action. By seeking out copies of itself (which would be in co-ethnics in higher frequencies), the gene is able to ensure its survival onto the next generation.
Even in couples who are not the same race or ethnicity match on other heritable characteristics. Rushton and Nicholson (1988), tested predictions from genetic similarity theory and found that spouses select each other on the basis of more genetically influenced cognitive tests. It’s known since The Bell Curve came out in 1994 that spouses select each other based on IQ. What Rushton and Nicholson noted in the study was that estimates of genetic influence calculated on Koreans and Canadians predicted assortative mating in European Americans in Hawaii and California. Americans of mixed ancestry made up for ethnic dissimilarity by matching up on the more heritable traits, whereas the correlation is lower for those traits that are more influenced by the environment. The observations on genetic selection were weaker but still had a positive correlation, when the g factor was taken out of the equation. This suggests that we choose mates based on the general intelligence factor. This effect is seen in, for instance, white women who date black men. They, more often than not, have lower average IQs than the mean (100).
Pan and Wang (2011) showed that spouses are similar in academic achievement as well as IQ. 6 out of the 8 traits tested (reading, spelling, arithmetic, vocabulary, verbal and full-scale IQ) showing evidence of spousal correlations.
Humans have a natural instinct to marry genetically similar others. Whether the traits are environmentally or genetically influenced, spouses will match on traits with the highest correlations (BMI, waist size, arm size). Genetic Similarity Theory proposes that these phenomena is not by chance, but was how we evolved. Sexual selection, which is natural selection arising through preference by one sex for certain traits in individuals of the other sex, is the driving factor here. Through sexual selection, we humans were able to gain higer intelligence (for men) and gain higher verbal abilties that allowed to care for children (women). These differences remained even when controlling for geographic location. Spouses and friends being as similar as 4th cousins is no accident, in fact, it is evolution in action.
[Edit: My view here has changed, read my recent article Is Diet an IQ Test? It isn’t and it is, of course, much more nuanced than ‘IQ’ (which is a proxy for social class’ leading to obesity which would imply lack of funds and education on what and when to eat. Obesity is much more complex than ‘IQ’, numerous other variables come into play and since ‘IQ’ (which is just a proxy for general knowledge ‘is low then the individual in question won’t know what and when to eat and since this occurs in low income families more often than not who have low IQs then this effects them the most.]
The relationship between intelligence and obesity is often misinterpreted. Numerous studies have concluded that becoming obese leads to a drop in IQ. This mistake happens due to improper interpretation of cross-sectional studies. However, analyses of population-based, longitudinal data show that low intelligence from birth causes obesity. No credible evidence exists for obesity lowering intelligence. There are, however, mountains of evidence showing that low intelligence from childhood leads to obesity (Kanazawa, 2014).
Kanazawa (2014), reviewed the data on the research between obesity and IQ. What he found was that those studies that concluded that obesity causes lowered intelligence only observed cross-sectional studies. Longitudinal studies that looked into the link between obesity and intelligence found that those who had low IQs since childhood then became obese later in life and that obesity does not lead to low IQ. Those with IQs below 74 gained 5.19 BMI points, whereas those with IQs over above 126 gained 3.73 BMI points in 22 years, which is a statistically significant difference. Also noted, was that those at age 7 who had IQs above 125 had a 13.5 percent chance of being obese at age 51, whereas those with IQs below 74 at age 7 had a 31.9 percent chance of being obese. This data makes it clear: low IQ is correlated with obesity, so we, therefore, need to find sufficient measures to help those with lower IQs to learn how to manage their weight. Moreover, the lack of ability to delay gratification is also correlated with low IQ (Mischel, Ebbeson, and Zeiss, 1972).
Less intelligent individuals are more likely to become obese than those who are more intelligent. With what we know about low IQ people and how there is a strong relationship between low intelligence and lack of ability to delay gratification, we can see how this lack of thought for future problems for their actions in the present can manifest itself in obesity.
This study claims that there is a link between morbid obesity and a drop in IQ. The researchers compared 24 children who weighed 150 percent of their bodyweight before age 4 with 19 children and adults with Prader Willi’s Syndrome, using 24 siblings as controls as “they share the same socioeconomic environment and genetics”. Prader Willi’s Syndrome (PWS) is a chromosomal disorder in which chromosome 15 is deleted. They have an almost insatiable desire to eat,which can cause one suffering from PWS to eat themselves to death. Those with PWS were found to have an IQ of 63, while those who became obese were found to have an IQ of 78 with the control siblings having an IQ of 106. The researchers were surprised to see such a difference in IQ between siblings. They then state that this could be one facet of obesity that could be irreversible. MRI scans of the cohort discovered white matter lesions on the subjects with PWS and early-onset obesity. The researcher says that these lesions could affect food seeking centers in the brain leading to a want to gorge on food. Seeing how those with PWS eat when unsupervised, this is an interesting hypothesis.
This study compared 49 teens with metabolic syndrome and 62 peers without the disorder, while controlling for socioeconomics status. They found significantly lower scores in arithmetic, attention and attention span, spelling, mental flexibility and regions of the brain with lower volumes of matter in the hippocampus and white matter integrity.
There are a few problems with these two studies. In a population-representative birth cohort study of 1037 children, it was found that cohort members who became obese had a low IQ, as expected. But, contrary to what your study said, cohort members didn’t exhibit a decline in IQ from becoming obese, they instead had a lower IQ since childhood. There is no evidence of obesity contributing to a decline in IQ, even in obese individuals and those on the verge of metabolic syndrome. Another problem is that they wrongly conclude that obesity leads to lowered intelligence, completely misinterpreting the extremely strong negative correlation between obesity and intelligence.
This study shows how obese mothers give birth to less intelligent children. In an observational study (already garbage), the researchers took 3412 participants and found a strong relationship with pre-pregnancy obesity and math and reading scores in children. For math, a 3 percent reduction was observed. There was a 3-point drop in reading scores with math scores showing a decline of 2 points. These differences are within the normal variation between tests, so it’s nothing to take note of. Also, this is an observational study. I have shown above that longitudinal studies are superior for this, as well as researchers misinterpreting the results found from their studies.
There is a strong relationship between parental years of education and childhood obesity. Since the mother’s IQ is the most important predictor of a child’s IQ *, that passes on to the child as well. (BMI is also 80 percent heritable). **.
So because of those factors involving the mother and child, that is what accounts for it. Not the environmental factors brought up.
This study claims that overweight parents are more likely to fail. This is all due to the fact that low IQ people are more likely to be obese or overweight, with heritability of BMI being .8, you can see how low IQ is the cause of both of those variables.
This shows that binge eating is linked to memory loss. I heard about a study a few months ago actually like this. Rats were fed high fat diets and they noticed that the brain microglia actually started to eat neuronal pathways actually leading to a decrease in cognitive ability. But they said that returning to a new diet will stop its effects. Researchers say the negative cognitive effects are reversible, but I already gave the citstion about obesity not being linked to decreased IQ. I should also note that this study was carried out on rats and while this may be a factor for humans as well, a few studies need to be done.
Binge eating, however, actually has a genetic component. Though this was only observed in girls. One reason I can think of for this is that women need higher body fat for a leptin release so puberty can begin so they can bear children.
This article purports to show 5 ways obesity affects the brain. Obesity does cause food addiction, however, those who lack the ability to delay gratification are more likely to not be able to control their impulse to overeat. I always link to the MRI scan showing the control, obese and cocaine user’s brain. Interesting to see that sugar is just as addictive as cocaine. Obesity doesn’t make us more impulsive. Check out the Marshmallow Experiment, as well as its follow-up studies. Those who are more impulsive are more likely to be obese, as well as have lower SAT scores.
Satoshi Kanazawa also noted that childhood IQ predicted whether or not one would become obese at the age of 51. General intelligence in childhood has a direct effect on weight gain, BMI, and obesity, net of parents education and SES, parents BMI, the child’s social class, and sex. More intelligent children grew up to make healthier choices, and therefore stayed leaner than those children who were less bright. The link between childhood obesity and intelligence also shows that the effect between childhood g is unmediated by education of income. Meaning, those with lower IQs in a higher socioeconomic bracket STILL have the same chance of becoming obese as those in the lower socioeconomic bracket. Finally, parental BMI itself is a consequence of parental general intelligence, which the parents pass on to their children. This shows the extremely high heritability of obesity as well as showing how intelligence plays a factor in the causes of obesity.
The known differences in ethnic obesity rates generally mirror the intelligence of those populations. All populations are showing a sharp dysgenic decline, which coincides with a more obese population as well. Sociologists and the like may say that those who are poor cannot afford the same types of food that those who have more wealth can. However, this is a false statement. Whole foods are not more expensive. The conclusion that was (obviously) reached is that there is expensive and non-expensive junk food as well as whole foods. Natural diets will not cost more, all things being equal. If you know how to eat and how to buy food, you will avoid spending too much money. This goes back to intelligence. One with a higher IQ will be able to think of what his present actions will lead to in the future while those with a lower IQ live in the now without a care for the future, which then manifests itself in their obesity.
There are numerous articles showing that the causality for low intelligence is not becoming obese, but that those who become obese have a lower IQ since childhood. Longitudinal studies show the relationship, while observational studies show that obesity drops intelligence. Clearly, observational studies are inferior for seeing the relationship between IQ and obesity. This then leads to researchers misinterpreting the data and drawing wrong conclusions.
** This is a great one. In a meta-analysis of twin and family studies, including mono and dizygotic twin studies, with a sample of 140,525 people, heritability of BMI was found to be between .75 and .82. Both extremely high correlations. Since the heritability of intelligence as well as height (another good predictor of intelligence), there is good evidence for the claim that becoming obese is due to lower childhood IQ, which is genetic in nature.
(Note, 6/24/17: Rushton’s r/K selection in applications to human races is dead. It’s been dead for almost 30 years after and ecologist critiqued his method and use of ecological theory in application to human races. Now, that doesn’t meant that everything written below—or even on my whole blog—is fully wrong, just that the attempted explanation is wrong. It still holds that Eurasians have worse fitness than Africans, which is partly due to deleterious Neanderthal variants, however, r/K theory does not explain it.)
Science Daily reported last week that Neanderthals left humans a genetic burden, which is having less offspring. Of course, these deleterious alleles only introgressed into non-African populations due to Africans not leaving Africa. This manifests itself today in birth rates within countries and between them based on the ethnic/racial mix. And (not) coincidentally, the areas with the highest rate of children are in sub-Saharan Africa.
The Neanderthals existed in small bands, so inbreeding was common. Due to this inbreeding, Neanderthals were more homogenous than we are today. When humans migrated out of Africa, they encountered the inbred Neanderthals who they interbred with. Harmful genetic variants acquired from Neanderthals are shown to reduce the fitness of populations with certain deleterious alleles. There are of course tradeoffs with everything in life. Increased intelligence and being better able to weather the Ice Age, among numerous other factors, were positive things gained from interbreeding with Neanderthals. Negative effects were the acquisition of deleterious alleles which still persist today in non-African hominids. These deleterious alleles decreased biological fitness which manifests itself in the birthrate of Eurasian populations throughout the world (the Germann and Japanese birthrate is 1.3 for reference).
Harris and Nielson also hypothesize that since Neanderthals existed in small bands that natural selection was less effective, allowing for weakly harmful mutations to pass on and not get weeded out over the generations. However, when introduced back into humans these effects become lost over time due to a large population with natural selection selecting against the deleterious Neanderthal alleles. Using a computer program, Harris and Nielson quantify how much of a negative effect the Neanderthal genome had on modern populations. The conclusion of the results was that Neanderthals are 40 percent LESS genetically fit than modern humans.
The researchers’ simulations also suggest that humans and Neanderthals mated more freely, which leads more credence to the idea that Neanderthals got absorbed into the Homo Sapien population and not mostly killed off. The estimation for Neanderthal DNA in modern hominids from the simulation was around 10 percent, which then continued to drop as the Neanderthal-Homo Sapiens hybrids interbred with those who hardly had any Neanderthal DNA. More evidence also shows that the percentage of Neanderthal DNA was higher in the past in Eurasians as well. Which makes sense since Asians have on average 20 percent more Neanderthal DNA than Europeans due to a second interbreeding event.
However, Harris and Nielson end up concluding that non-Africans historically had a 1 percent loss in biological fitness due to Neanderthal genetics. Moreover, a better immune system came from Neanderthal genetics. Skin color is another trait inherited from Neanderthals as well.
Along with the acquisition of deleterious Neanderthal alleles, early Eurasians also encountered the same environment as the Neanderthals. Those selection pressures, along with interbreeding due to small bands lead to a decrease in the number of children had. Fewer children are easier to care for as well as show more attention to. All of these variables in that environment lead to fewer children produced. It’s a better evolutionary strategy to have fewer children in more northerly climes than in more southerly ones due to the differing selection pressures. Environmental effects are also one reason why birthrates are lower for populations that evolved in northerly climes (Neanderthals and post-OoA hominids). Harsh winters lead to a decreased population size, as evidenced by the Inuit and Eskimoes, which their low population size didn’t allow for selection for high IQ despite having the same brain size as East Asians.
I couldn’t help but think that, yet again, for the second time in two weeks, one of JP Rushton’s theories was confirmed. This confirms one of the many variables of Rushton’s r/K Selection Theory. Just like I covered how Piantadosi and Kidd corroborated Rushton’s theory of brain size and earlier child birth. Neanderthals had bigger brains than we do today, and knowing what we know about the correlation between IQ, brain size and early childbirth, I would assume that Neanderthals also had earlier childbirths as well,.
Along with these deleterious gene variants from Neanderthals, other variables that contribute to the decline in Eurasian populations also include higher IQ as well, as JP Rushton says, is an extreme way to have control over their environment and individuality. These traits are seen in higher IQ populations in comparison to lower IQ populations. We could also make the inference that since Eurasian children have bigger heads, that multiple childbirths would be taxing on the Eurasian woman’s birth canal while it would be less taxing on the African woman’s.
This study also shows that Neanderthals also had less offspring due to being more intelligent. They had bigger brains than we do today, and since we know that higher IQ is correlated with fewer children conceived, we can say that they were pretty damn smart (they buried their dead 50,000 years ago. There was also a recent discovery of a 176,500-year-old Neanderthal constructions in a French cave). A main cause for the current trend in birthrates in Eurasian populations is due interbreeding with Neanderthals. These events also attributed more to the decline of the Neanderthals.
Deleterious Neanderthal alleles are yet another reason for lower Eurasian birthrates, which shows = that the current trend currently happening in the world with these populations is natural and evolutionarily based. I’ve said a few times that by showing positive things to women on television will increase the white birth rate, with Rushton cites National Socialist Germany as one example. By showing women happy with children, this lead to a massive boom in the German population. To ameliorate the effects of low natural birth rates, these positive things need to be shown on television to women to start to reverse the effects of low natural childbirths.
It’s been a great month for Rushton’s theories, with two of them being corroborated in one month. It’s only a matter of time before the denial of human nature is completely discarded from modern science. As the data piles up on human genetic diversity we will not be able to deny these clearly evident factors any longer.
Black American men are the least likely male ethnic group to be overweight or obese in America (69.2 percent) compared to ‘Hispanic’ men (78.6 percent) and white men (71.4 percent) (Ogden et al, 2014). As a result of being less likely to be obese, black men as a whole suffer from diabetes and other diseases that are correlated with higher body fat. Conversely, for women the rate for white women is 63.2 percent, 77.2 percent for ‘Hispanic’ women and 82.4 percent for black women. Why do black men have lower rates of obesity and chronic health diseases?
Klimentidis et al (2016) set out to find why black men have lower rates of obesity than black women despite having the same socioeconomic and environmental factors. Using 2814 self-identified African Americans from the Atherosclerosis Risk in Communities study, they estimated each individual’s degree of African ancestry using 3,314 genetic markers. They then tested whether sex modifies the association of West African genetic ancestry and body mass index, waist circumference, and waist to hip ratio. Also, they adjusted for income and education as well as examined associations of ancestry with the phenotypes of males and females separately. They recreated their results with the Multi-Ethnic Study of Atherosclerosis (n= 1611 AA).
They discovered that West African ancestry is negatively correlated with obesity as well as central obesity, which is obesity around the midsection, among black men but not black women. Also noted, was that black men with more African ancestry had a lower waist to hip ratio and less central adiposity than black men with less African ancestry. They conclude that their results suggest that a combination of male gender and West African ancestry is correlated with protection against central obesity and suggests that a portion of the difference in obesity (13.2 percent difference) may be due, in part to genetic factors. The study also suggests that there are specific genetic and physiologic differences in African and European Americans.
This study confirms two things. 1) Black women are more likely to be obese than black men as well as the general population. 2) Black men have less of a chance of becoming obese or overweight as well as less of a chance of incurring the risks that come along with being obese or overweight. The degree of African ancestry is the cause in both black men and black women for these differences in the rate of overweight and obese individuals in both populations. One of my theories also got confirmed. Since obesity is partly genetic in African Americans, and black girls have an earlier menarche (period) than white girls due to higher body fat which activates the hormone leptin, which precedes an increase in body fat to prepare for eventual menstruation, I theorize that black girls have earlier menarche than white girls due to r/K Selection Theory. It’s an evolutionary advantage to be able to have children earlier, as the population dies younger.
Evolutionarily speaking, black men needed to be more fit in order to protect the clan from predators. This is also why blacks evolved narrower hips (Rushton, 1995). Higher body fat allows for more protection for a baby in vitro, which is why an increase in leptin precedes an increase in body fat, which then causes black girls to have an earlier puberty.
One of the questions I would like answered is whether it’s the actual degree of African ancestry that is the cause of black men being less likely to be obese or it’s the cause of higher degree of European ancestry. European American men do have a slightly higher risk of being overweight or obese than African American men, so there is some credence to this hypothesis. Three SNPs were found to be correlated with obesity in African American populations as well as European American populations; this could be one cause.
Wagner and Heyward (2000) discovered biological differences exist between blacks and whites. They reviewed the literature on the differences between blacks and whites in fat-free body mass (water, mineral, and protein) fat patterning and body dimensions and proportions. Blacks, in general, have greater bone mineral density and body protein content than do whites, resulting in lower fat-free bone density. They also note racial differences in the differences of subcutaneous body fat, which is the body fat that’s just below the skin, as opposed to visceral body fat which is found in the peritoneal cavity, which can be measured with calipers to give a rough estimate of total body fat adiposity. The conclusion reached in the study was that differences in FFB (fat-free body) was statistically significant between blacks and whites. They also have a greater BMC (bone mineral content) and BMD (bone mineral density) than do whites. They also argue that for a given BMI (body mass index), blacks might have less adiposity because they tend to be more mesomorphic. Researchers push for the development of racial-specific equations to better see differences in FFB.
With the above study noting that there is a substantial difference between blacks and whites in FFB, there may be some truth to a negative effect of European ancestry on blacks in terms of obesity acquisition. However, lower FFB in black men is one reason why black men can’t swim as well as whites.
One of the causes for both racial and gender discrepancies in obesity is genetic in origin. The difference between black men and black women is 13.2 percent whereas for white men and white women the difference is 8.2 percent. There is a clear genetic difference between races that is the cause for this discrepancy. Black men and black women have the same socioeconomics status and live in the same environment, so some of the differences in obesity noticed in this population must be genetic in origin.
Freedman et al (2004) observed that, as expected, black men were more likely to choose heavier figures as an ideal body for women than white men. Also expected was that both groups would choose figures with a low waist to hip ratio, but black men would choose a lower waist to hip ratio as ideal. They also show weight to be a more important cue than waist to hip ratio in mate selection as well as supporting the theory that black men’s preferences may serve as a protective factor against eating and body image pathology in black women.
To give an example of the above study in action, we can look at Mauritania. They force feed their women up to 16,000 kcal a day in an effort to make them obese, as that’s what is seen as attractive in their society. Mauritanian love songs also describe the ideal woman as fat. Obesity is so celebrated in their society that parents beam at the fact that their daughters look obese, as they have a better chance of getting partners.
The higher the degree of West African ancestry in black men, the lower the chance they have for obesity. I do wonder, though, if it’s because they have less European ancestry or because they have more African ancestry. Black men with more African ancestry are less likely to be obese than black men with less African ancestry, so there is a correlation there that I would like to see explored in the future. Differences in fat-free body mass have been noticed between blacks and whites, but this is one of the first studies to my knowledge that shows that genetic differences between black men and black women may be part of the cause for obesity differences in that population. Cultural differences in perception of beauty, of course, come into play in regards to differences between black and white men, however, the cause of black women having higher rates of obesity is due in part to genetic factors, which then leads to black men liking that as their beauty standard.
The Chinese have one of the highest IQs in the world. Their 100 and 108 in Hong Kong give them an average of 104. Chinese intelligence has been increasing from the 1940s all the way to today. This is the ‘Flynn Effect’ in action. Lui and Lynn (2013) reported that IQ scores are improving for 12-year-old Chinese children. The increases are as follows: 6.19 points for full-scale IQ, 6.55 points for performance IQ, and 1.91 points for verbal IQ. The Jintan Child Study is an ongoing longitudinal study to show the effects of health and cognitive ability.
They used 1656 6th graders (55.5 percent boys and 45.5 percent girls, “consisting of 24.3% of all children in this age range in the Jintan city region born in 1999.”) who either graduated or currently were in the grade with an average age of 12.2 years. The study from 86-87 used only individuals from urban areas, so Liu and Lynn did the same. They conclude that over the 26 years from the original study, between the two data sets that increases of 2.38 points on full-scale IQ, .73 points on verbal, and 2.52 points on performance IQ per decade. They theorize that economic development is a cause of rising IQ scores due to better nutrition. The study concludes a 105.89 IQ for the 12-year-olds in the study.
Liu and Lynn (2015) also observed the same sex differences in the same magnitude in Chinese and American boys and girls. In a study of 788 children aged 12 years old, boys obtained a higher IQ by 3.75 points on average. This exactly mirrors what Rushton and Jackson (2005) say about American men and women who are college aged. They state that males score 3.63 points higher than women. Liu and Lynn state that boys obtained 4.20 points higher in performance IQ, and 2.40 points higher in verbal IQ. This is what we would expect, evolutionarily speaking. The men need to be more intelligent to provide food, whereas women need to have a higher verbal IQ to be able to talk to and take care of children. The fact that the magnitude of sex differences in IQ between men and women has been noticed in the U.S. and China shows that sex differences in the brain do exist.
Better nutrition is a definite cause for the rise in IQ for the Chinese. Richard Lynn says that better nutrition is critical for increased cognitive functioning. This is one reason why Africa’s IQ is so low. Due to more Chinese getting better jobs and making more money, they were getting higher quality foods in order to be adequately nourished. Better nutrition explains most, if not all of the Flynn Effect. It’s what to expect if this phenomenon was not on g (it’s not), it’s on the intelligence that is affected by the environment, hence, bigger increases on that type of intelligence in comparison to the intelligence highly correlated with g.
The Chinese have the largest cranial capacity at 1492 ml. The bigger one’s brain, the more cortical neurons it has which allows for better cognitive processing. Piantadosi and Kidd (2016) corroborated one of Rushton’s theories on brain size and child rearing. Mainly that r/K selection theory explains Piantadosi and Kidd’s theory of earlier births being correlated with higher intelligence due to greater necessity to care for the more vulnerable child in comparison to those with smaller brains. Moreover, since East Asians have more myelin in the brain, this too adds to their higher cognition. Since the correlation between brain size and IQ is .35, a good amount of the variance in IQ can be explained by brain size.
We can also look at Chinese outside of China. Singapore, for instance, has an IQ of 108, the highest in the world. They’re also 74.4 percent Chinese. This is then mirrored in their IQ as well as their economy. Anywhere the Chinese go they are high achievers in both IQ as well as wealth attainment.
There are other measures to show that Chinese have higher IQs. In tests of reaction times, Rushton and Jensen (2005) say that East Asians beat whites while whites beat blacks. Since faster reaction times are associated with a more efficient brain, East Asians have a higher IQ as a result of that. Though, they are weak on verbal IQ, average 99 for Chinese in America and China, they are superior in visio-spatial IQ. This is due to their ancestors evolving in the harsh winters of Siberia which lead to being more K-selected and selecting for bigger brains which lead to children being born earlier and higher intelligence evolving to better care for defenseless children. Bigger brains also evolved due to colder temperatures, which is another cause for earlier childbirth and an even bigger increase in general intelligence to adapt.
IQ in China is higher in urban areas than in rural areas, which is seen in America as well. This is due to those with higher intelligence having the ability to be able to live in the city due to a better ability to attain wealth due to higher IQ. Those in rural areas have lower IQ, some having a lower IQ genetically, while others are depressed by bad nutrition. So with better nutrition, a lot of the rural Chinese would get an IQ boost. Nutrition is critical for brain development in vitro as well as in early childhood leading into young adulthood. This ensures the brain has adequate nutrients for growth and in turn grows to its full potential.
The Chinese are the best example of Rushton’s theory of intelligence and brain size. No matter where they go, if they have adequate nutrition, they have the biggest brains and highest IQs which shows in scholastic achievement as well as wealth attainment. The increase in full-scale IQ for China in the past 30 years is due to better nutrition as well as economic growth. Singapore has one of the world’s best economies and is 74.4 percent Chinese.
This extreme K-selection, though, is causing the Chinese birth rate to drop. This is the curse for high IQ peoples. They have a lower birth rate in comparison to those with lower IQs who have a higher birth rate. The current birth rate in China is 1.66. That is devastatingly low, almost as low as Germany and Japan (both at 1.3) and they have similar IQs as well. It seems that this intelligence increase is coming with a lower birth rate. Higher intelligence is correlated with a lower sex drive so this is another cause for the lower birth rate in East Asian countries as these slight IQ increases continue to occur. The same sex differences as seen in America were also seen in China, giving more evidence to the sexual selection theory of intelligence.
I’ve read a lot of crazy things in my life, though this must be the craziest. Someone really believes that “blacks are less violent than whites“. To believe such a claim, you would have to close your eyes to all of the relevant data. From naming outright falsities to obscuring data to fit his narritive, this article will show and refute a distorted reality, one that the Left wishes to show, to one simply looking for the truth to interracial crime.
Don’t be modest, Caucasians. The Holocaust
The Holocaust is really beyond the scope of this blog, but check out the CODOH Library for the truth on this matter.
This is not unique to Europeans. The Rwandan Genocide (which was due to ethnocentrism) and the ethnic cleansing currently occurring in Central Africa aren’t real? Fact of the matter is, is that every ethnicity has participated in ‘ethnic cleansing’, which is really just protecting genetic interests. This is a non-factor as this has gone on before European colonialism.
Colonialism was good for the native inhabitants of Africa. Speaking of the Caribbean, how well did it end for the Haitians after they defeated Napolean?
Oh? You mean how a majority of the slaveholders were Sephardic Jews? Or how there are reports from New Orleans from their 1860 census that showed 3000 freed blacks owned slaves, accounting for 28 percent of the city’s population? In 1860 Louisiana, at least 6 blacks owned more than 65 slaves, with the biggest number of slaves being 165 slaves who worked on a sugar plantation. How about the Jews’ role in American slavery? Moreover, at the height of slavery, a paltry 6 percent of Southern whites owned slaves, when combined with the North it was 1.4 percent. An estimated 3000 blacks had about 20000 slaves in 1860. But tall is only about the whites who did slavery, and not about the Arabs and how they started enslaving Africans FIRST, in 650 AD.
The Alternative Hypothesis just had a post the other day about the non-genocide of American Indians. Basically, their population was anywhere between 1.5 and 2 million people. Population reduction for the Native Americans was only 0.22 percent!! Doesn’t seem like such a ‘genocide’ to me. If so, that’s the slowest genocide I’ve ever heard of.
People segregate naturally. We’re more segregated now than we were 50 years ago! Must be those residual effects from Jim Crow huh?
But somehow in the media it’s the black man who is portrayed as the savage.
It’s just not fair. We white folks are so much better at race-based aggression than our darker complected brothers.
More intelligent than them, that’s why.
Just this Wednesday a white guy walked into a historic African American Church in South Carolina, was accepted as part of the service, stayed for about an hour before shouting a spiteful message and gunning down several parishioners!
Now that’s some hate right there!
One person does something and that means….what exactly? It shows one person is hateful! Look at averages, not singular events.
Whenever anyone brings up race and violence, the first thing people mention is crime.
Because they are linked to each other. Why wouldn’t the two things be mentioned in the same breath?
There is more black-on-black crime than white-on-black crime, they say. And they’re correct!
According to a 2013 FBI Uniform Crime Report, when it comes to murder, 90 percent of black victims were killed by black offenders.
However, what people fail to mention is that according to the very same report, 83 percent of white victims were killed by white offenders, too.
These numbers don’t show black people are more violent than white people. They show that BOTH white and black people would rather kill within their own race.
Yea they show that both would rather kill within race, however you miss something very important here: Interracial crime!
First, we find that during the 2012/2013 period, blacks committed an average of 560,600 violent crimes against whites, whereas whites committed only 99,403 such crimes against blacks. This means blacks were the attackers in 84.9 percent of the violent crimes involving blacks and whites. This figure is consistent with reports from 2008, the last year DOJ released similar statistics. Perhaps not coincidentally, that was the year Mr. Obama was elected president.
In terms of raw numbers, black people and white people actually commit about the same number of murders. But you wouldn’t know that from the media.
Not really. Per capita rates are more important than raw numbers, luckily we have data on that!
As of 2008, young black men kill at a rate of 7 times higher than white men.
Is that the same number of murders?? I’m looking at the same stat in a completely different way than you are.
The FBI is charged under the Hate Crime Statistics Act with compiling statistics on spite-based legal transgressions. In its most recent report, for 2013, hate crimes based on race are far more numerous than any other kind.
- The FBI is biased towards blacks and ‘hate crimes’. How about all of the countless times we here about blacks attacking whites using racial epithets during the attack? Too many to count. They are, however, not counted as hate crimes by the FBI because it doesn’t fit their narritive.
- I wonder how those numbers would look if actual hate crimes were included in this data (black on white included).
According to the FBI statistics, 54.5 percent of the reported single-bias hate crimes that were racially motivated in 2013 targeted blacks. Only 16.3% target whites.
Want to talk bias? The amount of black on white hate crimes that are NOT categorized as such. This skews the statistics considerably.
Would our economy really have been so robust without the free labor of all those slaves?
Yes. Whites could have done it, but getting blacks to do it was cheaper and more efficient. Using brains to get ahead is what life is all about. Whites build great societies anywhere. Our economy would have been as robust as it is now without America never having a history of slavery.
Heck! Would we even have a country at all if we hadn’t murdered all those indigenous peoples in the first place?
Is a population decline of 0.22 percent per year ‘murdering all those indigenous peoples’?
So let’s put it to rest. When it comes to hate crimes, white folks kill! But don’t feel too bad, black folks. There are things you’re good at, too. Like nonviolent resistance.
This guy is delusional. Just because MLK preached non-violence doesn’t mean that blacks as a whole are non-violent. Look at crime stats from anywhere in the world.
After all this time, black people have very rarely used violence as a means to achieve their ends, to try to secure the rights and freedoms white America guards so jealously.
In just the past year or so, unarmed black folks have been assaulted or killed for holding toy guns
Go ahead and pick out the real one, then do it from a distance when you get a phone call that there is a kid walking around while waving a gun.
He died due to asthma, obesity, and heart disease, that’s why he couldn’t breathe; he was 350 pounds. He also did not comply with the officers’ orders, which is why he needed to be taken down in such a fashion.
listening to music at a gas station
Dunn did say that Davis said he was going to kill him with a shotgun and that’s when he grabbed his gun out of his glove box.
asking for help after a car accident
Freak accidents happen that get blown up? Damn, that proves whites are more violent huh!?!?
Yea, people still believe that Trayvon got killed for ‘wearing a hoody’. We have jurys for a reason. We have trials for a reason. We have laws like Stand Your Ground for a reason. Trayvon was killed because if Zimmerman hadn’t of protected his life, he would be dead. All of these people complaining about the verdict, if you were put into that same situation, would you allow yourself to be killed for fear of being called ‘racist’?
Listen to police when they tell you to do something. Especially during an investigation. This shouldn’t even need to be said.
1) The Baltimore Six are going to get off for it. They caused no harm. 2) He threw himself around in the back of the van causing his own death.
and now just going to church!
Right. They were killed just for going to Church. eyeroll
And the response from the black community has been pretty darn nonviolent. Yeah there’s been some shouting and looting, but very little beating or killing.
White folks, can you imagine having to undergo such indignity on a daily basis and NOT responding in kind!?
No wonder a blonde white girl from a Christian fundamentalist home darkened her skin, curled her hair and tried to pass as black! Sometimes – often really – it’s darn embarrassing to be white! Black folks have the moral high ground.
Because Dolezal is a moron. Blacks have the moral high ground? Please show me where this occurs.
Somehow they live in an American society that heaps hatred on their every move and they respond with dignity and perseverance.
There’s no reason at all for this right? Just good old fashioned ‘racism’?
So why are black people so nonviolent?
They aren’t. See the whole of sub-Saharan Africa to see how ‘non-violent’ they are.
Damned if I know! But I wish us white folks would take a lesson from them.
Yes!! The white man has tons to learn from the criminal black man! Much to learn about taking welfare and not working!!
Blacks have 2.5 to 4.9 percent higher testosterone than whites, which is causes more violence and crime. Beaver (2014) states that blacks who have the MAOA-L 2 repeat allele have significantly highier chances of being shot, stabbed or reporting shootings and stabbings than other genotypes. Blacks also have the highest rate of the 3 repeat allele (53 percent compared to 37 percent for whites) and 2 repeat allele (5 percent compared to .1 percent for whites). Moreover, he didn’t speak about how black violent crime is genetic in nature. This is mirrored in the crime rate and how violent blacks really are.
This is the age of the Internet where we have amassed tons of human knowledge which is readily available with a few hits of a few buttons. If people still want to be ignorant spewing falsities, it’s on them. But the truth is out there for those who seek it.
Blacks are not ‘non-violent’. Go to the nearest ghetto and see how ‘non-violent’ blacks are.
In the past 100 years since the inception of the IQ test there have been racial differences in test scores. What causes these score differences? Genetics? Environment? Both? Recently it has come out that populations do differ in allele frequencies that affect intelligence. David Piffer’s “forbidden paper on population genetics and IQ” was rejected by the new editor of the journal Intelligence. In the paper, he shows how IQ alleles vary in frequency by population. One reviewer even said it should not be put up for review, which Piffer believes there was a hidden agenda or a closed minded attitude. He even puts reviewers comments and responds to them. He says science should be transparent, which is why he’s showing the researchers’ comments on his paper.
His December, 2015 paper titled: A review of intelligence GWAS hits: Their relationship to country IQ and the issue of spatial autocorrelation shows that there are differing allele frequencies in which IQ between populations that affect IQ which are then correlated highly with average IQ by country (r=.92, factor analysis showed a correlation of .86). There was also a “positive and significant correlation between the 9 SNPs metagene and IQ”(pg. 45). However, Piffer does conclude that since the 9 alleles are present within all populations (Africans, Latin Americans, Europeans, South Asians, and East Asians) that the intelligence polymorphisms don’t appear to be race-specific, but were already present in Homo Sapiens before the migration out of Africa. He then goes on to say that it’s extremely likely that the vast majority of alleles were subject do differential selection pressure which lead increases in cognitive abilities at different rates rates in different geographical areas (pg. 49). It’s of course known that differing populations faced differing selection pressures which then lead to genotypic changes which then affected the phenotype. It’s not surprising that genes that correlate strongly with intelligence have differing frequencies in different geographical populations; it’s to be expected with what we know about evolution and natural selection. Below is the scatter plot showing the relationship between polygenic score GWAS (Genome Wide Association Studies) hits and IQ:
The fact that these differences exist should not come as a shock to those who want to seek the truth, but as seen with how David Piffer didn’t even get consideration for a revision, this shows the bias in science to studies such as this that show racial differences in intelligence exist.
Piffer’s data also corroborates Lynn and Meisenberg’s (2010) finding of a correlation of .907 with measured and estimated IQ. This shows that the differing allele frequencies affect IQ, which then affect a countries GDP, GNP, and over all quality of life.
With a sample with a huge n (over 100,000 subjects) cognitive abilities tests were performed on verbal-numerical reasoning, memory and reaction time (a huge correlate for IQ itself, see Rushton and Jensen, 2005). Davies et al (2016) discovered that there were significant genome-wide SNP based associations in 20 genomic regions, with significant gene-based regions on 46 loci!! Once we find definitive proof that intelligence differences vary between individuals, as well as the loci and genomic regions responsible, we can then move on to difference in allele frequency in depth (which Piffer 2015 was one of the starts to this project).
Moreover, genes that influence intelligence determine how well axons are encased in myelin, which is the fatty insulation that coats our axons, allowing for fast signaling to the brain. Thicker myelin also means faster nerve impulses. The researchers used HARDI to measure water diffusion in the brain. If the water diffuses rapidly in one direction, that shows the brain has very fast connections. Whereas a more broad diffusion would indicate slower signaling, thus lower intelligence. It basically gives us a picture of an individuals mental speed. Thinking of reaction time tests where Asians beat whites who beat blacks, this could possibly show how differing process times between populations manifest itself in reaction time. Since myelin is correlated with fast connections, we can make the inference that Asians have more than whites who have more than blacks, on average. The researchers also say that it’s a long time from now, but we may be able to increase intelligence by manipulating the genes responsible for myelin. This leads me to believe that there must be racial differences in myelin as well, following Rushton’s Rule of Three.
Since the mother’s IQ is the best predictor of the child’s IQ, this should really end the debate on its own. Sure on average, intelligent black mothers would birth intelligent children, but due to regression to the mean, the children would be less intelligent than the mother. JP Rushton also says that regression works in the opposite way. Both blacks and whites who fall below their racial means will have children who regress to the means of 85 and 100 respectively, showing the reality of the genetic mean in IQ between the races.
Why would differing allele frequencies lead to the same cognitive processes in the brain in genetically isolated populations? I’ve shown that brain circuits vary by IQ genes, and populations do differ in this aspect, like all other differing genotypic/phenotypic traits.
East Asians have bigger brains, as shown by MRI studies. Rushton and Rushton (2001) showed that the three races differ in IQ, brain size, and 37 different musculoskeletal traits. We know that West Africans and West African-descended people have genes for fast twitch muscle fibers (Type II) (Nielson and Christenson, 2001). Europeans and East Asians have slow twitch muscle fibers (Type I) for strength and endurance. (East Africans have this as well, which allows for ability to run for distance, which fast twitch fibers do not allow for. The same is true for slow twitch fibers and sprinting events.) Bengt Saltin showed that European distance runners have up to 90 percent slow twitch fibers (see Entine, 2000)! So are genetic IQ differentials really that hard to believe? With all of these differing variables in regards to intelligence that all point to a strong genetic cause for individual differences in other genes that lead to stark phenotypic differences between the races, is it really not plausible that populations differ in intelligence, which is largely inherited?
Is it really plausible that differing populations would be the same cognitvely? That they would have the same capacity for intelligence? Even when evolution occurred in differing climates? The races/ethnicities differ on so many different variables with differing genes being responsible for it. Would IQ genes really be out of the question? Evolution didn’t stop from the neck up. Different populations faced different selection pressures, so different human traits then evolved for better adaption in that environment. Different traits clearly developed in genetically isolated populations that had no gene flow with each other for tens of thousands of years. These differing evolutionary environments for the races put different pressures on them, selecting some for high IQ alleles and others for low IQ alleles.
We are coming to a time where intelligence differences between populations will become an irrefutable fact. With better technology to see how differing genes or sets of genes affect our mind as well as physiology, we will see that most all human differences will come down to differing allele frequencies along with differing gene expression. Following Rushton’s simple rule based on over 60 variables, East Asians will have the most high IQ alleles followed by Europeans and then blacks. The whole battery of different cognitive abilities tests that have been conducted over the past 100 years show us that there are differences, yet we haven’t been able to fully explain it by GWAS and other similar techniques. Charles Murray says within the next 5 to 10 years we will have definitive proof that IQ genes exist. After that, it’s only a matter of time before it comes out that racial differences in IQ are due to differing allele frequency as well as gene expression.