
Group differences in IQ are best understood as environmental in origin (pdf) - tokenadult
http://people.virginia.edu/~ent3c/papers2/nisbett2012groupdiffs.pdf
======
mhuffman
Rushton's assertion that there was some genetic influence is still not clearly
answered with this article, simply dismissed.

It is clear that environmental variables affect g-loaded test scores (one
example showed that black children raised in white households test higher than
black children raised in black households on average) almost always related to
family income, but there is still a weird small percentage that just can't be
explained away.

That is the genetic factor that Ruston and others believe exist. For example,
white and black children raised from birth in the same household
(predominantly white or black household, either one) have this weird gap where
the white kids test better on g-loaded assessments.

SAT scores are positively correlated to g-loaded test assessments. The College
Board's 2005 SAT data shows a 10 point combined advantage for white kids with
family income under $10,000 over black kids with family income over $100,000!

I have no idea the reason behind that leftover unexplained gap. I have never
read an article from the genetic or environmental side that adequately
explained it in context of the obvious difference that environment makes.

------
joe_the_user
If someone was trying to study the genetic inheritance of intelligence, you
would think he or she would want to look at more uniform groups than American
blacks and American whites. Given the considerable amount of immigration and
intermarriage modifying these group over time, both would appear fairly mixed
with "stock" beyond even the European and the African. And Europe and Africa
are wide, varied areas to begin with.

~~~
ars
A uniform social and educational environment is far more important for these
types of studies.

Comparing Africa And Europe makes that impossible - it's hard enough in the US
as it is.

------
gwern
Too bad we'll never see Rushton's reply, since he died a few days ago.

------
001sky
_Rushton (2012) asserted that the fact that Black performance falls further
behind White performance on subtests and items that have a higher g loading is
an indication of a genetic contribution to the Black/ White IQ gap. He
believes that a genetic hypothesis about the origin of the racial IQ gap would
predict this pattern of larger differences for more heritable, heavily gloaded
items, and that environmental ones would not. This belief is mistaken. The
construct of g would have no significance if it were not a measure of
cognitive complexity. If a group is environmentally disadvantaged, its
performance in comparison to nondisadvantaged groups will be greater on more
complex tasks than on less complex ones. If you have not played basketball for
many years, your performance will be closer to what it was previously for
layups than for fade-away jump shots._

\--Summary.

~~~
001sky
Disregarding the problematic use of (1) "groups" solely defined as [race]; and
(2) IQ as equivalent to [intelligence]; the <logical> extension of the
analysis with the words <in origin> as used in the title is specious. [#,$,!]

________

[#] ie. Logically ok would be _Group differences in IQ are best understood as
an [having an environmental component]._

=edit=

[$] Its logically possible (and most likely correct) that there are N
dimensions to intelligence that are consistent _in simultaneity_ (and while
still excluding race). EG, including non-racial defined genetic group
variation and environmental factors could both have measurable deterministic
impacts on outcomes, of order of magnitude equivalent value. Its problematic
to assert that the "origin" of [xyz] intelligence is an either/or hypothesis,
when its most likely a complex composite. For obvious reasons.

[!] Environmental impacts, once established, cannot then simutaneouly be
assumed as a neutral error variable (ie, with vanilla-stochasitic
distribution). Certainly not without micro-analytic support. The latter is not
evident / nor consistent with (1) or (2). Nor the use of basketball analogies.

------
bromang
[http://occidentalascent.files.wordpress.com/2010/12/800px-19...](http://occidentalascent.files.wordpress.com/2010/12/800px-1995-sat-
income211.png)

------
tokenadult
One of the best authors on this subject other than the joint authors of the
brief reply article submitted here is Jelte Wicherts, who has the especially
Internet-friendly habit of putting most of his papers up on his faculty
website so that readers who can't punch through paywalls can still read them.

<http://wicherts.socsci.uva.nl/>

Almost anything by Eric Turkheimer (one of the co-authors of the submitted
article, and on whose website I found the submitted article) is also good.

<http://people.virginia.edu/~ent3c/vita1_turkheimer.htm>

(Scroll down for live links to most of Turkheimer's recent papers, including
several current classics.)

Lars Penke is another researcher who shares most of this papers, many of which
are co-authored with star researchers on IQ or on human behavior genetics.

<http://www.larspenke.eu/en/publications.html>

AFTER EDIT: Following up on joe_the_user's comment, also a top-level comment,
I should point out that the United States Census Bureau has consistently
disavowed that "race" categories in the United States have anything to do with
biology or genetics.

"The U.S. Census Bureau collects race data in accordance with guidelines
provided by the U.S. Office of Management and Budget (OMB), and these data are
based on self-identification. The racial categories included in the census
questionnaire generally reflect a social definition of race recognized in this
country and not an attempt to define race biologically, anthropologically, or
genetically. In addition, it is recognized that the categories of the race
item include racial and national origin or sociocultural groups. People may
choose to report more than one race to indicate their racial mixture, such as
'American Indian' and 'White.' People who identify their origin as Hispanic,
Latino, or Spanish may be of any race."

<http://quickfacts.census.gov/qfd/meta/long_RHI525211.htm>

A similar statement is found as footnote 7 in the Census Brief 2010 "Overview
of Race and Hispanic Origin: 2010"

<http://www.census.gov/prod/cen2010/briefs/c2010br-02.pdf>

which reads

"The race categories included in the census questionnaire generally reflect a
social definition of race recognized in this country and are not an attempt to
define race biologically, anthropologically, or genetically. In addition, it
is recognized that the categories of the race question include race and
national origin or sociocultural groups."

An earlier statement by the Census Bureau for reports on the year 2000 census

<http://quickfacts.census.gov/qfd/meta/long_RHI625200.htm>

says, "The concept of race as used by the Census Bureau reflects self-
identification by people according to the race or races with which they most
closely identify. These categories are sociopolitical constructs and should
not be interpreted as being scientific or anthropological in nature.
Furthermore, the race categories include both racial and national-origin
groups.

"The racial classifications used by the Census Bureau adhere to the October
30,1997, Federal Register Notice entitled,"Revisions to the Standards for the
Classification of Federal Data on Race and Ethnicity" issued by the Office of
Management and Budget (OMB)."

In other words, the professional demographers who work on the United States
Census claim only to be following the law, not to be practicing biological,
anthropological, or genetic science when they ask for self-identification of
"race." That claim has continued through two different presidential
administrations as the bureau conducted two successive decennial censuses and
numerous community surveys. The Census Bureau practice is based on regulations
from the Office of Management and Budget (OMB), which were announced on 30
October 1997

<http://www.whitehouse.gov/omb/fedreg_1997standards>

to take effect no later than 1 January 2003 for data collection by all federal
agencies. The summary of comments on the 1997 regulations makes clear that not
all Americans are united in agreeing with the current set of categories. (The
categories used by the federal government have changed several times in my
lifetime.) The distinct differences between the categories used in the United
States and those used in any other country in the world should make clear that
categories are indeed "sociopolitical constructs and should not be interpreted
as being scientific or anthropological in nature." I bring this up because
several recent threads here on Hacker News have interpreted "race" categories
as if they have genetic or anthropological meaning, which they do not.

The long story about how to think carefully about race and ethnicity in the
human population can be found in the books recommended for first reading in a
Wikipedia user bibliography "Anthropology, human biology, and race citations
bibliography"

[http://en.wikipedia.org/wiki/User:WeijiBaikeBianji/Anthropol...](http://en.wikipedia.org/wiki/User:WeijiBaikeBianji/AnthropologyHumanBiologyRaceCitations)

in Wikipedia user space.

~~~
ars
> consistently disavowed that "race" categories in the United States have
> anything to do with biology or genetics.

They disavow it because it's politically poisonous any other way. But it's
obvious that race is genetic - all you have to do is look at the physical, and
heritable, characteristics.

And despite the "disavowment", practically speaking, most people are the
genetic race they claim.

~~~
eli_gottlieb
No, _ethnicity_ is genetic. Race is just something people made up.

Han Chinese, for example, are genetically distinct from ethnic Japanese, even
thought to an ignorant white man they both look "the same".

~~~
001sky
China= 1.25 Billion

Japan= 0.125 Billion

India= 1.X Billion

The use of race as a proxy for _uniform_ genetic variation is silly. It
follows (awkwardly) you cannot reject the hypothesis that genetics are
determinate, by rejecting analysis on race-based data. But that is only the
tip of the iceberg of problems here.

There is a logical problem and a data problem. The data problem is that race
is not a _proxy_ for genetic variation, per-se (mixed data). The logic problem
is that rejecting race as a hypothetical causal relationship does not reject
genetic variable (by proxy, since proxy=false). Furtermore, rejecting the
alternative hypothesis (ie, genetics) does not default to a single variable
solution (ie Envronment or Genetics is origin). You cannot reject the
hypothesis that they BOTH are important. Logically, they are not binary, per
observation.

The takeaway is that the headline is a problem. Reducing Environment to a one
of many simultaneous causal factors trivializes it.

Rejecting genetic determinants as having significant explanatory power is
counter-thetical to Evolution. This is an orthogonal point, but its important.
The Environment being "origin" implies that mate selection is irrelevant to
inherited/expressed/realized intelligence. Which is clearly false. As a
observed or as a logical matter.

Think of a car engine. Every manufacturer will have defects (manufacturing
tolerances). And poor maintenance will cause every engine to eventually fail
(ie, dont change the oil). So, (1) design is not determinate of performance
fully; and (2) environment can determine ultimate success/failure. It does not
follow that all egines have the same layout for internal cumbustion. Nor does
it follow that when working at full capacity/optimim tune they will have the
same power output. Nor can we conclude anything about the suspension or the
chassis performance, etc. But nor does it follow that ultimate performance (of
the complex system) cannot still be competitive (at least in certain
environments, etc). Cars of various design are competitive at road-rally, for
example.

While genetics is certainly not 100% explanatory, it simply is and must be a
component in the "origin of intelligence". Unless you are a crazy-tea-party-
sceptic-of-evolution.[sic]. So, this is problem for the intelligensia/left if
they want to divorce inherited/genetics from the disucussion.

The problem is the level of abstaction. We know genetics matters by species.
We know genetics matters by (nuclear) family. What are the in-between levels
(if any) that also matter? That is where things get murky and messy
(politically, logically, and otherwise). At some stage, this might also be
analysed of as a question of entropy. ie, if two smart people get married and
their kids are x/n likelt to be smart, at what stage in replication do they
revert to x/n= population average. If ever? What if their is persistent top-
quartile genetic pairings (ie, adding selective-diversity, etc). What if their
is a random sample from the population? Are the two vcases the same or
different? how do you tell/test? etc.

None of which should give cover for thinking without due clarity, however.

