Most Reported Genetic Associations with Intelligence are Probably False • Hacker News Board

Re: Most Reported Genetic Associations with Intelligence are Probably False

#31

Post by Guvante » Tue, Oct 08, 2013, 4:45 PM UTC

bayesianhorse wrote: post #24

rayiner wrote: post #20

Earlier quoted context omitted.

IQ is highly heritable: http://en.wikipedia.org/wiki/Heritability_of_IQ#Estimates_of... (estimates of adulthood heritability are 0.7-0.8, similar to height). We can reject the existence of an observed natural phenomenon because we can't explain it. We still haven't unified gravity with the standard model, but that doesn't mean we reject that gravity exists (for practical purposes or otherwise). The fact that a natura…

I qualified my statement with "for all practical purposes". I have often claimed that there is no practical relevance and no reasonable way to use this "fact" in practical real world decisions. Nobody was able to tell me one that holds up to even superficial checking. "Socially inconvenient" doesn't even come into it, because twin studies don't tell us anything about differences between two ethnicities. For that matt…

> The "intelligence is genetic" "fact" is often used to justify refusal to tackle socio-economic problems

Changing it wouldn't make a difference, everyone using that logic isn't basing their end goal on it, simply using it to justify their feelings.

Hell it took a while for me to understand the benefit of such improvements, and it had nothing to do with genetics. My problem was few people talk about the socio-economic impacts on capabilities, and the fact that counteracting programs can theoretically stop the death spiral in those groups.

However there are a lot of people who can't get over "not like me" and think the whole thing is a waste because it takes away from "hard working young men".

Re: Most Reported Genetic Associations with Intelligence are Probably False

#32

Post by Symmetry » Tue, Oct 08, 2013, 4:46 PM UTC

jcampbell1 wrote: post #22

tokenadult wrote: post #6

Earlier quoted context omitted.

It may be useful for the discussion here to define what "heritable" means. I like what Eric Turkheimer, a psychologist who investigates the heritability of human intelligence, says about that. "But back to the question: What does heritability mean? Almost everyone who has ever thought about heritability has reached a commonsense intuition about it: One way or another, heritability has to be some kind of index of how…

> Heritability isn't an index of how genetic a trait is. I am totally confused. My understanding is that heritability is a measure of how much genetics accounts for the observed variability in a given environment. I understand both that we don't understand the genetic recipe for height, but also that identical twins grow to be the same height. What is the author saying that I am missing?

I think the author is saying that the heritability of a trait depends on the range of environments being considered, but saying it in a needlessly grandstanding and obfuscatory manner?

Having now read the paper, yes, that was what he was saying, and the non-quoted sections of the paper are much clearer. Example

For the modeling underlying twin studies to make sense, one has to assume that the environments experienced by identical twins raised in the same family are no more similar than those experienced by frater- nal twins, that genes and environments are independent and additive (again, in the usual ANOVA sense) in the determination of the trait, and that parents mate randomly with respect to the trait.

That's totally true. If you compared an organism with a randomly generated genome to a human and exposed both to what would be a normal range of environments for a human, you would find that all traits are entirely genetic. And if you selected people from the normal range of human genetics but only gave half of them access to important things like a uterus then you would find that all traits are almost entirely environmentally determined. So you can't say that "Trait Foo is 50% heritable" unless you also specify the populations and range of environments you're talking about.

EDIT: Or you could say that heritability is ordinal but not cardinal, given some reasonable assumptions.

Re: Most Reported Genetic Associations with Intelligence are Probably False

#33

Post by Guvante » Tue, Oct 08, 2013, 4:46 PM UTC

no_wave wrote: post #16

Do we even have a working definition for intelligence at this point that can't have holes poked in it from every direction?

No. A unified definition may be impossible.

But not having a concrete definition doesn't make certain inferences impossible.

Re: Most Reported Genetic Associations with Intelligence are Probably False

#34

Post by epistasis » Tue, Oct 08, 2013, 4:46 PM UTC

btilly wrote: post #7

This whole field seems likely to be a case study supporting http://xkcd.com/882/ . But the research does have a questionable assumption. On p 5 it says, "Such a result would not likely be due to differences in the methods used to generate g in the various datasets under comparison, since g is consistently measured by a wide variety of tests." This is true. However it is also true that, as http://vserver1.cscs.lsa.umi…

> This whole field seems likely to be a case study supporting http://xkcd.com/882/.

The scientifically interesting thing is that it's not at all like that XKCD cartoon. Multiple hypothesis testing is built into the design of the studies, and has been from the very start. When it comes to proper interpretation of stats in science, geneticists are at the top of the hierarchy.

Your second point is far closer to what I think is going on, but I still think that single-gene studies are the wrong way to go, as you might guess from my username. They're testing for the wrong thing, single locus or single gene causes, of a very complex phenotype with the involvement of many many different loci and genes. So if there are 500-600 genes that are important, maybe one passes the test in your particular subsample, but in a different subsample the rest of the 500-600 genes mediate the effect. I.e. there's not enough complexity in the model to account for the signal. What's worked very well for simple diseases and traits may not work well for complex traits with the influence of many many different genes.

Re: Most Reported Genetic Associations with Intelligence are Probably False

#35

Post by TeMPOraL » Tue, Oct 08, 2013, 4:48 PM UTC

bayesianhorse wrote: post #25

JackFr wrote: post #21

Earlier quoted context omitted.

I'm not sure if you are misreading the article or disagreeing with it, but in either case you're wrong. The fact that a 'wrongness gene' hasn't been, and may not ever be, identified does not undermine my assessment, but rather indicates current models of the interaction of genes and wrongness might be naive, and the interactions are probably deeper and more complex.

Please tell me one "practical purpose" were "Intelligence is largely genetic" as a use...

Off the top of my head: eugenics, diverting the smarter parts of population to science and leadership roles.

Not saying it's moral, but definitely and obviously practical.

Re: Most Reported Genetic Associations with Intelligence are Probably False

#36

Post by jcampbell1 » Tue, Oct 08, 2013, 4:49 PM UTC

bayesianhorse wrote: post #24

rayiner wrote: post #20

Earlier quoted context omitted.

IQ is highly heritable: http://en.wikipedia.org/wiki/Heritability_of_IQ#Estimates_of... (estimates of adulthood heritability are 0.7-0.8, similar to height). We can reject the existence of an observed natural phenomenon because we can't explain it. We still haven't unified gravity with the standard model, but that doesn't mean we reject that gravity exists (for practical purposes or otherwise). The fact that a natura…

I qualified my statement with "for all practical purposes". I have often claimed that there is no practical relevance and no reasonable way to use this "fact" in practical real world decisions. Nobody was able to tell me one that holds up to even superficial checking. "Socially inconvenient" doesn't even come into it, because twin studies don't tell us anything about differences between two ethnicities. For that matt…

"intelligence is genetic" and "intelligence is heritable" are completely different statements. The notion that IQ is fixed and encoded in genes is nonsense. What is true is that for a given environment, the variation in observed IQ is strongly explained by genetics. It is possible, and likely true, that lower intelligence among minorities is caused by the environment, but that the variation among those in this environment is explained by genetics.

The fact that intelligence is heritable says nothing about social-economic policy for changing the environment. It is as absurd as saying that because "height is genetic" there is no reason to worry about malnutrition.

Re: Most Reported Genetic Associations with Intelligence are Probably False

#37

Post by Symmetry » Tue, Oct 08, 2013, 4:53 PM UTC

tocomment wrote: post #30

Wouldn't intelligence be 100% genetic. I mean humans have intelligence and insects have way less. And all that programming to make one or the other is encoded in the DNA.

You could just as easily argue that it's 100% environment, since a human who is never provided with food will end up dead, and therefore much less intelligent than an insect.

Re: Most Reported Genetic Associations with Intelligence are Probably False

#38

Post by bayesianhorse » Tue, Oct 08, 2013, 5:02 PM UTC

TeMPOraL wrote: post #35

bayesianhorse wrote: post #25

Earlier quoted context omitted.

Please tell me one "practical purpose" were "Intelligence is largely genetic" as a use...

Off the top of my head: eugenics, diverting the smarter parts of population to science and leadership roles. Not saying it's moral, but definitely and obviously practical.

This might be practical, but it does not make for a proven profitable use of the "fact". Currently it is way easier to test children/students/workers for intelligence or academic achievement rather than subject them to a genetic test or pedigree inspection.

Pedigrees and genetic testing in animal breeding are way more useful. But there you have completely different structures and goals. And some of them, particularly diseases with high heritability like canine hip displasia, can't be solved by current genetics yet.

Re: Most Reported Genetic Associations with Intelligence are Probably False

#39

Post by nether » Tue, Oct 08, 2013, 5:07 PM UTC

thetruthhurts wrote: post #29

thetruthhurts wrote: post #23

"African Americans currently score lower than European Americans on vocabulary, reading, and mathematics tests, as well as on tests that claim to measure scholastic aptitude and intelligence. This gap appears before children enter kindergarten (figure 1-1), and it persists into adulthood. It has narrowed since 1970, but the typical American black still scores below 75 percent of American whites on most standardized t…

Continued: I think it's pretty obvious that genes have quiet a bit to do with intelligence and achievement. There have been too many studies done on race and iq, race and crime, race and achievement to just throw out. I'm not the smartest but at least I'm living in reality. And I'm proud to see so many HNers here doing the same and acknowledging the important role genetics has in our lives. It's good to know there's…

It's only racist if you think the value of a person is tied to his intelligence. Achievement is definitely related to intelligence, but I don't think achievement makes one better than another.

Re: Most Reported Genetic Associations with Intelligence are Probably False

#40

Post by RodericDay » Tue, Oct 08, 2013, 5:21 PM UTC

thetruthhurts wrote: post #29

thetruthhurts wrote: post #23

"African Americans currently score lower than European Americans on vocabulary, reading, and mathematics tests, as well as on tests that claim to measure scholastic aptitude and intelligence. This gap appears before children enter kindergarten (figure 1-1), and it persists into adulthood. It has narrowed since 1970, but the typical American black still scores below 75 percent of American whites on most standardized t…

Continued: I think it's pretty obvious that genes have quiet a bit to do with intelligence and achievement. There have been too many studies done on race and iq, race and crime, race and achievement to just throw out. I'm not the smartest but at least I'm living in reality. And I'm proud to see so many HNers here doing the same and acknowledging the important role genetics has in our lives. It's good to know there's…

you know, under this kind of racist mindset, I don't know why other races would just sit pretty and accommodate a system that arbitrarily puts caps on their own nature-given superior traits (you would say, strength and charisma) in favor of allowing other races' superior traits (i would say, lack of empathy and greed) dominate.

i guess what I'm trying to say is that it'd be fun seeing you try to stand tall and pontificate about the importance of institutionalizing all sorts of unfounded, intuitionist beliefs about race- nevermind the fact that race is hard to determine in a large number of cases- to the detriment of individuals if society didn't put an arbitrary limitation on their exploitation of strength for personal gain

no i guess what i'm trying to say is that usually racists are dweeby ugly little people that stand proud on the shoulders of the achievements of those who they perceive to be 'kin' (nevermind jewish/irish/italian/slav/etc. divisions from yesteryear), and that i wouldn't mind seeing you publicly made fun of and/or beat up because of it.