Reddit Reddit reviews The g Factor: The Science of Mental Ability (Human Evolution, Behavior, and Intelligence)

We found 15 Reddit comments about The g Factor: The Science of Mental Ability (Human Evolution, Behavior, and Intelligence). Here are the top ones, ranked by their Reddit score.

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The g Factor: The Science of Mental Ability (Human Evolution, Behavior, and Intelligence)
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15 Reddit comments about The g Factor: The Science of Mental Ability (Human Evolution, Behavior, and Intelligence):

u/CharlesHipster · 22 pointsr/4chan

> IQ is highly dependent on social environnement, family and school education and the subject's personality.

WRONG. That's where you are wrong, kiddo.

  1. Attempts by programs like head start to give blacks highly enriched educational environments have failed to produce lasting changes in their IQ’s relative to whites.

  2. Children of black parents that make between $160K and $200K a year are less intelligent than white children from families that make less than $20K a year. Similarly, the IQ difference between rich black kids and rich white kids is even larger than the IQ difference between poor black kids and poor white kids.

  3. Our society has obviously become much less “racist” over the last hundred years. Yet, the black/white IQ gap is basically the same today as it was in 1918.

  4. Genetic theory predicts that the children and grand children of smart people will tend to be ever dumber until they reach the average IQ level of the population. The children and grand children of smart black parents “regress” in this way to a mean IQ of 85 while the children of smart white parents regress to a mean IQ of 100. The only obvious explanation for this comes from genetics.

  5. Whites have larger brains than blacks. This seems to be for genetic reasons since there are also many other muscular and skeletal differences between blacks and whites that are associated with evolving larger brains and because these brain size differences are present at birth. Larger brains are also associated with being more intelligent. Three lines of evidence suggest that this association is causal: first, genes that are associated with being more intelligent are also associated with larger brains. Second, a person’s brain size changes over time ]predict changes in their intelligence over time]( And third, smarter siblings have larger brains their their less intelligent siblings who grew up in the same home as them (this suggests that the relationship can’t be explained by any possible confounding variable in the family environment such as nutrition). So it seems that whites have evolved to be more intelligent than blacks partly by evolving larger brains.

  6. Mulattos (people who have a black and a white parent) have higher IQ’s than blacks but lower IQ’s than whites. A genetic explanation would predict this because half of a mulatto’s genes are black and half are white. In fact, even with in black populations those who have lighter skin (because they have more white ancestors) have higher IQ’s.

  7. The Minnesota trans-racial adoption study, which is the best of its kind, found that at age 17 blacks adopted into upper middle class white homes averaged an IQ of 84, Mulattos averaged 93, and whites 102. Thus, being raised in an affluent white family didn’t boost black or Mulatto IQ just as a (mostly) genetic hypothesis would predict.

  8. Some IQ sub-tests are more heritable than others. (That is, twin studies show that differences between individuals on some tests are more due to genetic differences between people than others.) The race IQ gap is largest on those subtests with the highest levels of heritability and the only obvious explanation for this is that the B/W IQ difference is caused by genetics.

  9. Versions of genes associated with intelligence differ in frequency between the races in such a way that favors white people.

  10. Egalitarianism isn’t evolutionarily or genetically plausible. We know that the different environments the races evolved in produced differences in just about every physical trait from bone density to height to muscle size. And we know that the large differences in weather and food availability must have caused people to behave differently. The idea that these different environments selected for intelligence with exactly equal pressure seems incredibly unlikely. Similarly, studies have found that the races differ in the frequency of most (or all) genes and this includes genes that affect brain development. So the races possessing any random single gene in the same frequency is unlikely. In order for them to have to same genetic profile with regards to intelligence, which involves thousands of genes, this would have to happen thousands of times. If we assume that that the probability of the races having the same frequency for some gene is 40% (it’s actually much lower) and that intelligence involves 15 genes (it actually involves thousands) the probability that the races would have the identical frequencies for each of these genes is 0.0001%. Given this, the idea that they would have the exact same frequency for the thousands of genes that affect intelligence is basically impossible.
u/xzxzzx · 14 pointsr/science

> but to claim that it's a measure of intelligence is pretty far fetched.

I suggest reading The g Factor to get a better understanding of IQ tests insights and limitations.

To summarize, while it's true that some people are better at certain mental tasks than others, there is a strong correlation between a huge subset of mental tasks. If a person is good at, say, mental spatial manipulation, they tend to be good with language, good with pattern recognition, etc.

u/Paranoid_Android3 · 5 pointsr/DebateAltRight

Anyone that's read much of The g Factor will immediately dismiss the notion that Jensen was some racist crank. You can borrow it here, not sure how that works.

u/[deleted] · 2 pointsr/GreatApes

If you're really interested read "The g factor"

Then tell your friends who say it's all whitey's fault to shove it.

u/Boxcar_Overkill · 2 pointsr/AskThe_Donald

I don't think life is completely fair, just as it's not fair to short people, people that are unattractive, etc. But the question is, is the "unfairness" the primary cause of the problems in the African American community or is it something else?

This is difficult to talk about, and I don't want to hurt anyone's feelings. There are certainly many very smart people of every race and each individual has to be judged on their own merits.

But many of the problems facing the black community may be explained by that graph. That is a horrible thought but that doesn't make it an untrue thought.

The gap exist, even when one controls for socio-economic status. I'm not saying the SES isn't relevant, only that it doesn't explain the difference. Roughly speaking, caucasians in the poorest 1/5 of the country score about the same as African American's in the richest 1/5 of the country. So I don't know that your "redneck" analogy is accurate, or at least I would ask for evidence.

Here is a 2nd hand graph taken off researcher Arthur Jensen's book showing the effect of SES on IQ. The same stats exist for SES and SAT scores.

It's not clear whether or not anything can be done about all of this. But if there is, that would seem like it would be the first thing we should do, because none of the other issues are going to go entirely away if that one isn't solved.

u/jmeehan11 · 2 pointsr/politics

Crime by Race
Because of the obscure way in which the FBI reports the race and ethnicity of offenders, we had to make several approximations. First off, Hispanic data is separated from race data and is broken down to "Hispanic" or "not Hispanic" for the entire dataset. While it is safe to assume that most Hispanics were classified as white because of the colour of their skin, we didn't want to make any assumptions. To figure out the percentage of Hispanic offenders and separate it from the white, black, asian etc. race categories, we used Census data on how Hispanics identify themselves racially. Not surprisingly, the vast majority of them identify as white, and very few consider themselves black. Given the very low percentage of black Hispanics, we counted "Some Other Race" as white. Another problem with the FBI dataset was the vast number of "Unknown" reported offenders. Because we couldn't make any reasonable assumptions about the race of the unknown offenders, we used the arrest tables as a proxy for the distribution of crime by race.

2014 City Crime Data:
City data from the U.S. Census Bureau:
City Crime data from the FBI:

Historical Crime


Poverty and Welfare

Single Mothers and Divorce



Spanking Prevalence

u/TheConnections · 2 pointsr/changemyview

Wow. Well I apologize for being lazy and posting an unreliable source. However I think you wasted your time "debunking" that article. Firstly, both of your sources are the same thing. Secondly here and here: "" are two more reliable sources. The purpose of these studies are to explain why African American men are at a dramatically higher risk for prostate cancer.

That was not my main point anyways. My point was "pseudo-science" is called when it involves racial differences, even if the reasoning is sound.

> IQ is heritable. It is also influenced by numerous other factors, as listed in your wiki link, such as access to education, health, nutrition, pollution, socio-economic status, etc, etc, etc.

Of course it is. It is influenced by environment and also genetics.

> There is a shitton of studies showing this. However, there is not a single credible study which remotely concludes in any way that race and IQ share a causal relationship.

Have you heard of The Bell Curve and The g Factor?

> Never heard of the guy. Sounds interesting. I'll look into it.

Oh are you familiar with most human genetics professors? Yes, do look into it. I provided you two sources.

> But that doesn't mean big brains = big smarts.

It addresses that in the article

u/RedHermit1982 · 1 pointr/DebateAltRight

> Placing something on a spectrum doesn't invalidate the application of categories, in this case race, to spots on said spectrum

The application of categories (taxonomy), in general, isn't invalidated. What's invalidated is the use of race, which is primarily defined by a narrow set of phenotypes, in particular skin color, as the method for defining these categories because it obscures greater genotypical similarities between groups and also has less predictive power than groupings based on other genetic differences, such as clines and clusters.

Even if you use continental origin based on AIMs to match self-identified race and ethnicity with most recent ancestry, that doesn't yield a grouping that has any utility whatsoever as a unit of analysis for biology and genomics.

For example Michael Jackson's daughter is self-identified black. So is Barack Obama. Both have one white parent and one black parent, but Obama looks black and Paris Jackson looks white, like really white. Blue eyes and everything. You could trace both of their genetic ancestries to Africa and group them on that basis, and it would match their SIRE 100 percent, but if you put them in the same environment, same SES, etc., Paris Jackson would be treated like a white person.

> By this reasoning you can't distinguish between red and green because there is no clean dividing line as you move through the electromagnetic spectrum from one to the other.

I would say that this is a clever bit of sophistry were it not for the fact that it's totally unoriginal and I've heard it used so many times that it has become cliche.

It's a false analogy. Color is defined by one specific property, i.e. wavelength, that is fixed and uniformly agreed upon to be a set value 510 nm. Phenotypes are influenced by thousands upon thousands of different alleles, most of which—particularly the ones for intelligence— have not even been identified. Even skin color involves hundreds of genes.

A difference on the electromagnetic spectrum between green (510 nm) and red (650 nm) is not analogous to the genetic difference between any given population, even defined in the most narrow sense, i.e. clines, much less in a broad sense using archaic 19th-century folk taxons like Caucasoid, Mongoloid and Negroid.

The genetic difference between any two groups or individuals is less than 10 percent, so a more accurate analogy would be a comparison of two different shades of green at 510 nm and 515 nm, which would be indistinguishable.

> The far ends of the spectrum can't interbreed

Yeah, isolation-by-distance is a thing but it hasn't existed as a phenomenon for long enough to actually result in substantial differences between say Native Americans and Bantus, except for certain specific climate-related adaptations, like sickle-cell anemia.

> So if you want to throw out race because of this you'd have to throw out species too.

No, I don't have to throw out the concept of species or the concept of subspecies but in order to apply the taxonomies in a useful way, biology requires a non-arbitrary genetic threshold for defining them, and race doesn't meet this criteria (between 17 percent and 25 percent genetic difference). Again, there is only one subspecies of Homo sapiens. It's called sapiens and like it or not, we're all part of it.

> It means exactly what I think it means, it's a ratio between genetic and environmental variation. So, yes, it changes in different environments

OK, so if you understand it so well, then you also understand it only applies to differences between individuals in the same population with the same environment and it can't be generalized to apply to average group differences between populations.

To do so is a misapplication of the concept in the same way that Rushton abused r-K selection, using it in a way that no respectable biologist would.

As I already noted elsewhere in the thread, Mackintosh, the author of "IQ and Intelligence," notes that at the lowest SES, heritability approaches zero.

And even Rushton and Jensen, the most vociferous proselytizers of hereditarianism, had to acknowledge: "A high heritability within one group does not mean that the average difference between it and another group is due to genetic differences, even if the heritability is high in both groups."

Of course, that didn't prevent them from trying to push this argument over and over and over and coming up short each time when their theories were put to the test by other more scrupulous researchers.

In fact this statement by Jensen directly contradicts his earlier statement in which he critiqued Lewontin's seed and soil analogy. Jensen said in 1970 that a high heritability increases the probability that genetics play a role in average group differences. And repeated this claim in his 1998 book.

So what happened in between 1998 and 2005 that caused Jensen to qualify his statement?

In a little more than three decades, we see Jensen walk back his position from "differences in IQ are mostly genetic" to "differences in IQ are about half and half" to "differences in IQ are partially genetic but in some unquantifiable amount that can't be 100 percent falsified with existing research methods.

Respectable scientists like Wicherts don't a priori rule out the role of genetics in between-group difference, but that's just good science. In other words you retain a healthy amount of skepticism until empirical evidence can tell you with a degree of certainty the cause of an observed phenomenon.

Race reductionists use this uncertainty to keep the dream alive much like creationists.

> If I control for environment tightly enough to yield a high heritability and I still have a gap, then a large chunk of that gap is likely due to biological factors not the environment.

Now we are getting into the limitations of social science. What I find most ironic about "race realism" is that many of its proponents frequently malign the social sciences as not "real science," yet the entirety of the argument is based on a few psychologists that I can count on one hand all drawing from the same tainted well.

This disdain for the social sciences also manifests in an inability to actually understand social science methodology and interpret the results of research accurately. It also causes them to erroneously assign equal weight to studies that make highly speculative claims that fail to achieve consistency with the bulk of scientific literature (Lynn and Rushton) as studies that do (Nesbitt et. al)

And here's the rub: You're never going to be able to control for the social effects of blackness, such as stereotype threat, stigma and institutional racism/discrimination. And to dismiss those factors offhand as irrelevant or non-existent is unscientific.

Even if you control for SES and differences remain, it doesn't necessarily follow that the basis of those differences is purely genetic.

As anthropologist John Ogbu observed, there is a difference between "caste-like minority groups," such as blacks who immigrated involuntarily and voluntary immigrants like Chinese and Jews who carried with them a culture of self-respect..

In the social sciences, one could conceivably construct an experiment in which you compared the educational outcomes of half-black white-presenting students from similar backgrounds as half-black black-presenting students, and measure the effect of the appearance of blackness on social outcomes. But it would be hard to get a big enough sample size and to replicate.

I much more prefer the relatively straightforward (and falsifiable) tales that genetics tells. Namely that variation within species is very small.

The only way to test differences between races in a concrete falsifiable to determine how much is genetic would be to identify all or most of the thousands of genes that contribute to intelligence and to define get a massive DNA sample that is representative of the various population clusters that exist within the black and white races. Then you would have to compare the samples for allele frequency.

The cost of doing this is prohibitively expensive at the moment even as GWAS costs go down. But given the overall low variation between population groups, the default position has to be that differences in IQ are mostly, if not entirely, environmental.

u/hitssquad · 1 pointr/teslamotors

College is not a way to increase one's long-term income unless one wants to become an academic. See:

I run two businesses, and there is no way I would ever hire anyone with a college degree.

u/satanic_hamster · 1 pointr/CapitalismVSocialism

> Which is?

The ones I directly linked to in his thread. The collected academic papers of experts put together by Nyborg, the summary of the entire field by Haier, the work on the g factor by Jensen, I even directly linked to the American Psychological Association which makes the same claim.

When the APA comes out and takes your stance on the issue, I'll 100% retract my claim.

u/J-B-D · 1 pointr/Libertarian

Do you want to post the link again? Sure beats quoting a passage from it that proves your straw man?

Here I'll post it too.

u/ELS_BrigadeWarning · 1 pointr/ferguson


>In a Raven Standard Progressive Matrices test, the subject is tested with patterns and geometric figures which are culture-independent and a computer calculates the score.

>These tests correlate significantly (over .50) with IQ

>And as expected, despite having no cultural bias, they continue to show the large, measurable, and significant intelligence gap between Whites and Blacks.

>To date, despite claims that IQ tests are biased, not one single intelligence test has ever displayed equal scores for Blacks and Whites; one must either make the test so difficult that nobody can manage to get the questions correct or so easy that everyone obtains a perfect score to show testing equality, yet that would make the test meaningless and invalid.

>Trillions of dollars have been spent in attempt to erase this Black-White IQ gapand all have failed. PSnew.pdf

>In fact, "public schools now spend more per capita on black children than on white." Also, "Contrary to environmentalist predictions, intervention beginning at age three makes no difference to the intellectual development of blacks [into adulthood]."

>The famous Milwaukee Project which spent $14 million in attempt to prove that the IQ gap could be removed with improved environment ended with the principal investigator "convicted and imprisoned for large-scale abuse of federal funding for private gain. Two of his colleagues were also convicted of violations of federal laws in connection with misuse of project funds… However, the project received uncritical acceptance in many college textbooks in psychology and education." (Google)

>As Albert Einstein famously wrote, "Insanity is doing the same thing over and over again and expecting different results." All of the excuses for Black underachievement have been refuted ad nauseam yet egalitarians refuse to budge, persisting that race doesn't exist and that this gap is the fault of White racism.

>Egalitarians often suggest that White racism lowers Black self-esteem and causes an inferiority complex. However, "Past research indicates that black adolescents consistently have higher self-esteem than white students. Other research demonstrates that self-esteem has positive effects on academic achievement. However, black students have lower academic achievement than white students while concurrently exhibiting higher self-esteem."

>Indeed, even the psychologist Claude Steele who coined the term "Stereotype threat" (anxiety or concern to conform to a negative stereotype) admitted that it does not explain the gap between Whites and Blacks through personal email. One study reports that "research is widely misinterpreted… as showing that eliminating stereotype threat eliminates the African American-White difference in test performance."

>IQ gaps between Whites and Blacks are observable at the age of three, prior to cultural influences or potential effects of racism.

>Blacks mature faster than Whites

>The IQ gap reflects this; the gap is 0.7 standard deviation (1 SD is 15 points) at early childhood, 1 SD at middle childhood, and 1.2 SD into early adulthood.

>About 37% of Blacks have an IQ below 80, while only 9% of Whites do. Blacks are 6x as likely to have an IQ of 70 or less as Whites, 12% of Blacks compared to 2% of Whites. Half of Whites have an IQ over 100 (average) but only 16% of Blacks do. Only 1% of Blacks have an IQ over 120, but 9% of Whites do.

>The ASPM gene of Chromosome 1 has been shown to effect brain morphology and defects lead to smaller brains and low IQ.

>A new ASPM allele arose in Eurasia and has been suspected at increasing intelligence and has been demonstrated to be absent in Blacks.

>The MCPH1 gene of Chromosome 8 with alleles known as "microcephalin" partly determine brain size and morphology

>Beneficial alleles are common in Eurasians but rare in Blacks. The MCPH1 and ASPM gene correspond with the development of hand-crafts and the development of sophisticated cities which were common in Eurasian populations but unheard of in sub-Saharan Africa.

>The DCDC2 gene of Chromosome 6 effects brain morphology and the ability to read.

>One alelle results in dyslexia

>"The allele frequency of the A allele rs2274305 of the dyslexia-gene DCDC2 is about 0.28 among Eurasians and 0.99 among Yorubas from Nigeria, about 0.80 among African-Americans."

>The DTNBP1 gene has also been linked to intelligence, specifically the rs:760761, rs:2619522 and rs:2619538 alleles. For rs:760761, 18% of Whites carry the T allele, which takes off 8 IQ points, compared to 37% of Blacks. For rs:2619522 carrying the G allele takes off 7 points, and is found in 18% of Whites and 35-36% of Blacks. The rs:2619538 T allele increases IQ by 6.5 points and 61% of Europeans carry it vs 67% of Blacks.

u/jakefromstatefarm10 · 1 pointr/rickandmorty

I know what the anthropologists say but I really do not believe them in the slightest.

I can't really seem to find anything to back up "adopted children perform less well in school" theory so the study is pretty conclusive it's simple biology.

If you really think it's not biological still then you did not actually read anything I posted in an unbiased matter.


Source 1:

Source 2:

Source 3: Is from this book ( page 288

Source 4: Is from this book ( page 358