/sci/ - Science & Math

>anecdotal evidence
Keep denying science.

== Genetic Basis for Human Intelligence Confirmed ==
Genome-wide association studies establish that human intelligence is highly heritable and polygenic
Molecular Psychiatry; 9 August 2011; doi:10.1038/mp.2011.85

"Our results unequivocally confirm that a substantial proportion of individual differences in human intelligence is due to genetic variation, and are consistent with many genes of small effects underlying the additive genetic influences on intelligence."

"We estimate that 40% of the variation in crystallized-type intelligence and 51% of the variation in fluid-type intelligence between individuals is accounted for by linkage disequilibrium between genotyped common SNP markers and unknown causal variants."

www.nature.com/mp/journal/vaop/ncurrent/full/mp201185a.html

== IQ Reflects Anatomical Brain Differences ==
Genetics of Brain Structure and Intelligence
Annu. Rev. Neuroscience; 2005. 28:1–23; doi: 10.1146/annurev.neuro.28.061604.135655

"Genetic influences on brain morphology and IQ are well studied. A variety of sophisticated brain-mapping approaches relating genetic influences on brain structure and intelligence establishes a regional distribution for this relationship that is consistent with behavioral studies. We highlight those studies that illustrate the complex cortical patterns associated with measures of cognitive ability. A measure of cognitive ability, known as g, has been shown highly heritable across many studies. We argue that these genetic links are partly mediated by brain structure that is likewise under strong genetic control."

loni.ucla.edu/~thompson/PDF/TT_ARN05.pdf

>>4110193
I'm not bad at math. I'm above average in math, but not stellar. My post wasn't about myself to begin with--I don't know why you even brought it up.

>>4110176
Brain size is correlated with intelligence.
http://www.springerlink.com/content/r173v725160tn626/
>brain size is correlated with cognitive ability about .44 using MRI

Since IQ is polygenic, no one factor will likely be a sole determinant for IQ. Ceteris paribus, however, a larger brain does mean some degree of higher IQ.

>>4110172
I know what neuroplasticity is. What I wonder is whether you know what it is. It doesn't mean that you will get more intelligent by trying. The most common form of neuroplasticity is recovery from brain or nerve damage. If you lose an arm, it is still possible for the nerves and neurons to behave as though the arm still existed ("phantom limbs"). This has nothing to do with intelligence--and it really was hijacked by radical egalitarians who believed (or simply tricked themselves into believing) that neuroplasticity=total malleability of intelligence.

http://en.wikipedia.org/wiki/Neuroplasticity

Short answer, yes. IQ is highly heritable. Regression to the mean will occur, but if high IQ people continue to breed exclusively with other high IQ people, the mean to which IQ in the offspring regresses will gradually increase.

Info on genetics and IQ:
== Genetic Basis for Human Intelligence Confirmed ==
Genome-wide association studies establish that human intelligence is highly heritable and polygenic
Molecular Psychiatry; 9 August 2011; doi:10.1038/mp.2011.85

"Our results unequivocally confirm that a substantial proportion of individual differences in human intelligence is due to genetic variation, and are consistent with many genes of small effects underlying the additive genetic influences on intelligence."

"We estimate that 40% of the variation in crystallized-type intelligence and 51% of the variation in fluid-type intelligence between individuals is accounted for by linkage disequilibrium between genotyped common SNP markers and unknown causal variants."

www.nature.com/mp/journal/vaop/ncurrent/full/mp201185a.html

== IQ Reflects Anatomical Brain Differences ==
Genetics of Brain Structure and Intelligence
Annu. Rev. Neuroscience; 2005. 28:1–23; doi: 10.1146/annurev.neuro.28.061604.135655

"Genetic influences on brain morphology and IQ are well studied. A variety of sophisticated brain-mapping approaches relating genetic influences on brain structure and intelligence establishes a regional distribution for this relationship that is consistent with behavioral studies. We highlight those studies that illustrate the complex cortical patterns associated with measures of cognitive ability. A measure of cognitive ability, known as g, has been shown highly heritable across many studies. We argue that these genetic links are partly mediated by brain structure that is likewise under strong genetic control."

loni.ucla.edu/~thompson/PDF/TT_ARN05.pdf

First off, IQ is at least 51% heritable at a low estimate. This was the conclusion of a recent GWAS (genome wide association study) [8]. This is not some wishy-washy psychology study: This conclusion is the result of genetics and statistics. With that study, bookshelves of books and articles downplaying the existence or heritability of IQ were suddenly rendered obsolete.

Regression to the mean is counter-intuitive. In short, IQs tend to sway toward the population average. See [1] for a theoretical (statistical) explanation of IQ regression to the mean.

A note on the first term of the formula, the mean IQ of the populations (<span class="math">\bar{x}[/spoiler]). In [4], we find a somewhat superficial explanation:
>"It is often stated that regression takes place towards the mean of an individual's own population; but any particular individual may belong to several different populations, for example he may be a member of one social group or a geographical region etc. However, the regression phenomenon relates to averages of expected values and our expectations will vary according to our information about the individuals concerned."
The report gives an example of the heritability of height, and suggests that an affluent child's population should be that of other affluent peers, not underclass or poor people. We can readily see the biological explanation being that higher nutrition is present in affluent populations, leading to probably taller stature. The mean IQ of one's ethnic group is a factor in "population" value in regression to the mean [5].

Well, you would be lying and preaching deprecated, anti-scientific doctrines.


== Genetic Basis for Human Intelligence Confirmed ==
Genome-wide association studies establish that human intelligence is highly heritable and polygenic
Molecular Psychiatry; 9 August 2011; doi:10.1038/mp.2011.85

"Our results unequivocally confirm that a substantial proportion of individual differences in human intelligence is due to genetic variation, and are consistent with many genes of small effects underlying the additive genetic influences on intelligence."

"We estimate that 40% of the variation in crystallized-type intelligence and 51% of the variation in fluid-type intelligence between individuals is accounted for by linkage disequilibrium between genotyped common SNP markers and unknown causal variants."

www.nature.com/mp/journal/vaop/ncurrent/full/mp201185a.html

== IQ Reflects Anatomical Brain Differences ==
Genetics of Brain Structure and Intelligence
Annu. Rev. Neuroscience; 2005. 28:1–23; doi: 10.1146/annurev.neuro.28.061604.135655

"Genetic influences on brain morphology and IQ are well studied. A variety of sophisticated brain-mapping approaches relating genetic influences on brain structure and intelligence establishes a regional distribution for this relationship that is consistent with behavioral studies. We highlight those studies that illustrate the complex cortical patterns associated with measures of cognitive ability. A measure of cognitive ability, known as g, has been shown highly heritable across many studies. We argue that these genetic links are partly mediated by brain structure that is likewise under strong genetic control."

loni.ucla.edu/~thompson/PDF/TT_ARN05.pdf

BACKGROUND (1/2)

There has been abundant research on the heritability of IQ in the field of psychometrics since the turn of the 20th century with Francis Galton's work. It has since evolved into a heavily statistical science. For neophytes, I recommend leafing through these slides, which provide an overview of what we know about psychometrics: goo[dot]gl/v6I13 They are from a presentation by Steve Hsu (a physicist with a strong side interest in psychometrics).

An individual's IQ is influenced by the IQs of the parents. There is a certain coefficient of heritability directly from their IQs. However, there is also a component of heritability that seems counterintuitive. It is regression to the mean. In short, IQs tend to sway toward the population average, regardless of the parent's IQs. The phenomena has not, to my knowledge, been ascertained in genetic terms (although a general rule of biology is that extreme traits regress to normalcy after x number of generations), but IQ regression to the population mean exists as a statistical fact. See [1] for a theoretical (statistical) explanation of IQ regression to the mean.

A note on the first term of the equation, the mean of the populations (<span class="math">\bar{x}[/spoiler]). It seems like ambiguous phrasing because of the sensitivity of what it represents. What we mean by "population" is really an aggregate of one's socioeconomic and demographic status. In [4], we find a somewhat superficial explanation:
>"It is often stated that regression takes place towards the mean of an individual's own population; but any particular individual may belong to several different populations, for example he may be a member of one social group or a geographical region etc. However, the regression phenomenon relates to averages of expected values and our expectations will vary according to our information about the individuals concerned."

>>3841695
== Genetic Basis for Human Intelligence Confirmed ==
Genome-wide association studies establish that human intelligence is highly heritable and polygenic
Molecular Psychiatry; 9 August 2011; doi:10.1038/mp.2011.85

"Our results unequivocally confirm that a substantial proportion of individual differences in human intelligence is due to genetic variation, and are consistent with many genes of small effects underlying the additive genetic influences on intelligence."

"We estimate that 40% of the variation in crystallized-type intelligence and 51% of the variation in fluid-type intelligence between individuals is accounted for by linkage disequilibrium between genotyped common SNP markers and unknown causal variants."

www.nature.com/mp/journal/vaop/ncurrent/full/mp201185a.html

== IQ Reflects Anatomical Brain Differences ==
Genetics of Brain Structure and Intelligence
Annu. Rev. Neuroscience; 2005. 28:1–23; doi: 10.1146/annurev.neuro.28.061604.135655

"Genetic influences on brain morphology and IQ are well studied. A variety of sophisticated brain-mapping approaches relating genetic influences on brain structure and intelligence establishes a regional distribution for this relationship that is consistent with behavioral studies. We highlight those studies that illustrate the complex cortical patterns associated with measures of cognitive ability. A measure of cognitive ability, known as g, has been shown highly heritable across many studies. We argue that these genetic links are partly mediated by brain structure that is likewise under strong genetic control."

loni.ucla.edu/~thompson/PDF/TT_ARN05.pdf

== Genetic Basis for Human Intelligence Confirmed ==
Genome-wide association studies establish that human intelligence is highly heritable and polygenic
Molecular Psychiatry; 9 August 2011; doi:10.1038/mp.2011.85

"Our results unequivocally confirm that a substantial proportion of individual differences in human intelligence is due to genetic variation, and are consistent with many genes of small effects underlying the additive genetic influences on intelligence."

"We estimate that 40% of the variation in crystallized-type intelligence and 51% of the variation in fluid-type intelligence between individuals is accounted for by linkage disequilibrium between genotyped common SNP markers and unknown causal variants."

www.nature.com/mp/journal/vaop/ncurrent/full/mp201185a.html

== IQ Reflects Anatomical Brain Differences ==
Genetics of Brain Structure and Intelligence
Annu. Rev. Neuroscience; 2005. 28:1–23; doi: 10.1146/annurev.neuro.28.061604.135655

"Genetic influences on brain morphology and IQ are well studied. A variety of sophisticated brain-mapping approaches relating genetic influences on brain structure and intelligence establishes a regional distribution for this relationship that is consistent with behavioral studies. We highlight those studies that illustrate the complex cortical patterns associated with measures of cognitive ability. A measure of cognitive ability, known as g, has been shown highly heritable across many studies. We argue that these genetic links are partly mediated by brain structure that is likewise under strong genetic control."

loni.ucla.edu/~thompson/PDF/TT_ARN05.pdf

== Genetic Basis for Human Intelligence Confirmed ==
Genome-wide association studies establish that human intelligence is highly heritable and polygenic
Molecular Psychiatry; 9 August 2011; doi:10.1038/mp.2011.85

"Our results unequivocally confirm that a substantial proportion of individual differences in human intelligence is due to genetic variation, and are consistent with many genes of small effects underlying the additive genetic influences on intelligence."

"We estimate that 40% of the variation in crystallized-type intelligence and 51% of the variation in fluid-type intelligence between individuals is accounted for by linkage disequilibrium between genotyped common SNP markers and unknown causal variants."

www.nature.com/mp/journal/vaop/ncurrent/full/mp201185a.html

== IQ Reflects Anatomical Brain Differences ==
Genetics of Brain Structure and Intelligence
Annu. Rev. Neuroscience; 2005. 28:1–23; doi: 10.1146/annurev.neuro.28.061604.135655

"Genetic influences on brain morphology and IQ are well studied. A variety of sophisticated brain-mapping approaches relating genetic influences on brain structure and intelligence establishes a regional distribution for this relationship that is consistent with behavioral studies. We highlight those studies that illustrate the complex cortical patterns associated with measures of cognitive ability. A measure of cognitive ability, known as g, has been shown highly heritable across many studies. We argue that these genetic links are partly mediated by brain structure that is likewise under strong genetic control."

loni.ucla.edu/~thompson/PDF/TT_ARN05.pdf

Going to copypasta this everyday until people get it. IQ clearly measures a biological trait. It doesn't get any more "real" than that.

== Genetic Basis for Human Intelligence Confirmed ==
Genome-wide association studies establish that human intelligence is highly heritable and polygenic
Molecular Psychiatry; 9 August 2011; doi:10.1038/mp.2011.85

"Our results unequivocally confirm that a substantial proportion of individual differences in human intelligence is due to genetic variation, and are consistent with many genes of small effects underlying the additive genetic influences on intelligence."

"We estimate that 40% of the variation in crystallized-type intelligence and 51% of the variation in fluid-type intelligence between individuals is accounted for by linkage disequilibrium between genotyped common SNP markers and unknown causal variants."

www.nature.com/mp/journal/vaop/ncurrent/full/mp201185a.html

== IQ Reflects Anatomical Brain Differences ==
Genetics of Brain Structure and Intelligence
Annu. Rev. Neuroscience; 2005. 28:1–23; doi: 10.1146/annurev.neuro.28.061604.135655

"Genetic influences on brain morphology and IQ are well studied. A variety of sophisticated brain-mapping approaches relating genetic influences on brain structure and intelligence establishes a regional distribution for this relationship that is consistent with behavioral studies. We highlight those studies that illustrate the complex cortical patterns associated with measures of cognitive ability. A measure of cognitive ability, known as g, has been shown highly heritable across many studies. We argue that these genetic links are partly mediated by brain structure that is likewise under strong genetic control."

loni.ucla.edu/~thompson/PDF/TT_ARN05.pdf

== Genetic Basis for Human Intelligence Confirmed ==
Genome-wide association studies establish that human intelligence is highly heritable and polygenic
Molecular Psychiatry; 9 August 2011; doi:10.1038/mp.2011.85

"Our results unequivocally confirm that a substantial proportion of individual differences in human intelligence is due to genetic variation, and are consistent with many genes of small effects underlying the additive genetic influences on intelligence."

"We estimate that 40% of the variation in crystallized-type intelligence and 51% of the variation in fluid-type intelligence between individuals is accounted for by linkage disequilibrium between genotyped common SNP markers and unknown causal variants."

www.nature.com/mp/journal/vaop/ncurrent/full/mp201185a.html

== IQ Reflects Anatomical Brain Differences ==
Genetics of Brain Structure and Intelligence
Annu. Rev. Neuroscience; 2005. 28:1–23; doi: 10.1146/annurev.neuro.28.061604.135655

"Genetic influences on brain morphology and IQ are well studied. A variety of sophisticated brain-mapping approaches relating genetic influences on brain structure and intelligence establishes a regional distribution for this relationship that is consistent with behavioral studies. We highlight those studies that illustrate the complex cortical patterns associated with measures of cognitive ability. A measure of cognitive ability, known as g, has been shown highly heritable across many studies. We argue that these genetic links are partly mediated by brain structure that is likewise under strong genetic control."

loni.ucla.edu/~thompson/PDF/TT_ARN05.pdf