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Massive Study Searching For Genes Behind Intelligence Finds Little
An anonymous reader writes: It's been taken for granted that science would, one day, figure out what parts of our DNA make us smart (or not). But a huge new study done by a group of almost 60 researchers using genome data on over 100,000 people has come up empty-handed. The scientists first looked for differences in the genome that correlated with academic achievement. After narrowing it down to 69 individual sites, they gave cognitive tests to separate group of 24,000 people and looked for evidence of difference at those same locations (abstract). Most of the sites weren't significantly different from chance — the (already weak) genetic influence of genes on height has an effect 20 times greater. On top of that, the three gene locations that did seem to have a stronger correlation weren't involved in development of the nervous system.
GATTACA becomes a little less plausible!
But what of this story?
http://science.slashdot.org/st...
"When information is power, privacy is freedom" - Jah-Wren Ryel
the researchers were coincidentally all missing a particular gene and none of them could figure out what its purpose was.
My parents are both dumber than dirt but I'm way smarter than them.
the (already weak) genetic influence of genes on height has an effect 20 times greater
Wait... did I just read that genes only have a weak influence on height?????
Googling "genes for height"
Height clearly has a lot to do with genetics - shorter parents tend to have shorter children, and taller parents tend to have taller children...
Okay, phew! I must have misinterpreted the meaning of "already weak genetic influence." Also, each of those articles do go on to explain that nutrition, including fetal nutrition, have a significant impact as well.
...the brain really is just for cooling the blood after all.
Well, sorta.
There's a lot more evidence that in-utero nutrition has a big role to play on intelligence. In fact, it's a commonly cited possible causal mechanism behind the Flynn effect.
So... you might be born with dramatic differences in your eventual (general) intelligence already in play, but that doesn't necessarily implicate genetic determinism.
Also intuitive is the fact that genes do play a role in the difference between human intelligence and apes. Just not necessarily between humans. So genes do something. Just not as much as "racial realists", social Darwinists, and other genetic determiminst believers contend.
The summary is incorrect, please read the abstract to form your own opinion. Specifically:
"Convergent evidence from a set of bioinformatics analyses implicates four specific genes (KNCMA1, NRXN1, POU2F3, and SCRT). All of these genes are associated with a particular neurotransmitter pathway involved in synaptic plasticity, the main cellular mechanism for learning and memory. "
Intelligence is highly heritable, but there is no single 'genius' gene and often there are multiple genetic markers that have similar positive or negative effects. This study looked for common genetic variants that correlated with memory and learning and found them!
The genes are obviously smart enough to hide from researchers.
The study did not demonstrate this at all. It simply failed to find specific genes responsible for intelligence.
You might still be born with a set intelligence which isn't genetically determined, or it might be genetically determined on the basis of genetic factors that were not identified for any number of reasons. Or you could be right.
The point is, this study doesn't provide any evidence one way or another.
Also, equating academic performance with intelligence may be dubious. There could be many factors responsible for academic performance, of which intelligence is just one. We can't even define what intelligence is...
The counterpoint here is twin studies. Identical twins, born to the same parents, but adopted by different families, tend to have extraordinarily unlikely similarities in adult general intelligence scores. What this study has been undermining is the notion that because it tracks from birth, it has mostly to do with genes.
Instead, this suggests there are other conditions that identical twins share besides genes. As I said in my earlier post, a lot of expertise has been focused on in-utero development instead.
The irony. The smart people couldn't figure out what makes someone smart... perhaps because they were using the wrong parameters.
Identical twins only separate at birth, so all we've got evidence of is that intelligence is largely set prior to that event.
I'm going to guess that we really need to studied identical twins, separated PRIOR to implantation and carried by different mothers. Problem with this is such experiments are not exactly ethical.
"File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
Not quite true.
It shows that a large number of specific candidate genes don't do it. Even if it's not a complete refutation of the hypothesis, it is a push to maybe look elsewhere for some of the mechanisms of intelligence development.
Well, it only would show that those genes don't have an individually-detectable affect on whatever marker they looked at. Maybe collectively they have an effect that can't be detected statistically. Maybe the marker they chose doesn't make sense.
Imagine if I tried to identify the gene for "sickness." I took anybody who ever got sick for any reason and studied their DNA and looked for a common link. Most likely I wouldn't find anything. Would this prove that genes can't make you sick? Or is it more likely that "sickness" is such a broad description of a phenotype that it could have a billion different causes.
Academic performance could be the result of MANY factors. Physical attractiveness has been demonstrated to have an impact on academic performance, and you'd hardly expect the same genes to affect that as your ability to do some kind of mental processing. That is just picking one attribute that is obviously going to confound results. Then you get into stuff like whether intelligence is about persistence, or ability to process information, or memory, etc. All of those things are likely to affect academic performance. Then there are cultural factors - let's just assume the sterotype about Asians prodding their kids to study harder is true - I'm sure there are alleles more common in Asians (the fact that they have distinctive appearances makes this obvious for starters), and that is going to confound things.
If you really want to identify the genes responsible for a trait, you have to first come up with a very precise definition for the trait, ideally one tied to some kind of biological mechanism (good luck if it involves the brain).
Or in other words, they simply were not smart enough to find the genomes. We know that a large amount of intelligence is dictated by our genes (http://science.slashdot.org/story/14/08/11/1151242/about-half-of-kids-learning-ability-is-in-their-dna), that we are unable to find a few needles in the haystack does not makes us rethink that.
Troll is not a replacement for I disagree.
I don't think it's narcissistic. This reads like "please validate the ethical value I've invested into Social Darwinism" to me.
You could also just compare them with fraternal twins.
In this case the genetic starting points are different, but the in-utero contributions are the same.
From the original paper:
http://www.pnas.org/content/ea...
We identify several common genetic variants associated with cognitive performance using a two-stage approach: we conduct a genome-wide association study of educational attainment to generate a set of candidates, and then we estimate the association of these variants with cognitive performance. In older Americans, we find that these variants are jointly associated with cognitive health. Bioinformatics analyses implicate a set of genes that is associated with a particular neurotransmitter pathway involved in synaptic plasticity, the main cellular mechanism for learning and memory. In addition to the substantive contribution, this work also serves to show a proxy-phenotype approach to discovering common genetic variants that is likely to be useful for many phenotypes of interest to social scientists (such as personality traits).
How the hell does the article now writes that "The scientists first looked for differences in the genome that correlated with academic achievement"? No, they looked for "educational attainment". Then the abstract goes on "Three SNPs (rs1487441, rs7923609, and rs2721173) are significantly associated with cognitive performance after correction for multiple hypothesis testing." SNPs are different alleles of the same gene.
Then, "Convergent evidence from a set of bioinformatics analyses implicates four specific genes (KNCMA1, NRXN1, POU2F3, and SCRT). All of these genes are associated with a particular neurotransmitter pathway involved in synaptic plasticity, the main cellular mechanism for learning and memory." But the article states that " On top of that, the three gene locations that did seem to have a stronger correlation weren't involved in development of the nervous system."
What the hell??
http://www.mueller-public.de - My site http://www.anr-institute.com/ - Advanced Natural Research Institute
Gene Expression drives a lot of things and that is not captured when just the DNA is investigated.
They weren't trying to correlate intelligence with genes. They were trying to correlate educational attainment with genes. That is not the same thing. People don't always apply their full intelligence towards school. Also, doing well and going far in school doesn't prove much about one's intelligence. It proves one can remember facts long enough to regurgitate them in a test. I suppose that is a kind of intelligence but there is much more to it than that! I think that having an analytical mind and actually thinking about those facts can get in the way of the study, regurgitate, forget, repeat process and is therefore detrimental to one's grades.
I thought one of the most remarkable studies was the one that showed conjoined twins tend to live in the same city. That blew me away.
Dark Reflection
They were looking for "academic achievement", not necessarily intelligence, per se.
This issue is a bit more complicated than you think.
Spoiler, they have, and the results are... less than fully informative.
From a purely genetic basis, whereas identical twins have a 95-100% similarity on these things, you might expect a 50% similarity from fraternal twins in a purely genetic environment. Instead, it comes out to 70%, which suggests other factors playing an important role. However, because these are non-isolated from environmental factors(i.e. raised by the same parents), we can't use it to precisely tamp down the amount of a role genetics plays.
Maybe a bigger sample size would help, but conclusions are limited, other than genetics plays some role which we already knew.
self-made *gasp* one-percenters?
There's no such thing. Everyone with that kind of wealth either inherited it or got extremely lucky. Its not possible to become mindbogglingly wealthy through hard work and diligence; there's no such thing as a "self-made millionaire".
The AT article seems to try to put a spin on it, but the actual abstract sounds quite different:
It's clear from twin studies that IQ has a strong genetic component, about as strong as height: both have a heritability of around 0.8 (on a scale from 0 to 1, with 1 being variability being entirely genetically determined). Here's a bit more info on heritability from Nature: http://www.nature.com/scitable...
Failing to find the genes responsible in this study means nothing since the current SNPs we test for are quite limited. Ultimately, these questions can only be resolved by full genome sequencing of large numbers of people. Until then, we may get lucky in identifying genes in these kinds of studies, but failure to find something means little. And, actually, they did find something interesting.
They're all a bunch of idiots.
Research shows that 67% of those who use the term "research shows", are just making shit up.
That is does not seem to be genetically just adds to the mystery. But there are other failures: While intelligence can be described by its effects, there is no theory at all how it works. The only existing model (automated theorem proving) is severely limited both by the nature of what it can do (construct mathematical theory) and by its inherently exponential effort which means it will never be able to do in practice hat smart human beings can do routinely. Then there is this little problem that intelligence has only been observed coupled with self-awareness and may also be tied to "free will", another two things that are not understood at all. Granted, most people are not really adept at using what intelligence they have (which routinely is also not that much), but it is still a defining quality for being a human being. It is really surprising that this quality proves intractable time and again.
Now, there is a branch of religious fanatics called "physicalists" that insist everything is just "chemistry" or "physics". These people routinely vastly overestimate what is known scientifically and seem to be completely unable to deal with some rather fundamental things being unknown at this time. All typical characteristics of the religious fanatic. It is rather ironic that there people usually claim to be anti-religion and pro-science, when they have in fact invented their own disconnected-from-reality fantasy. These people usually neither understand the scientific process, nor what is known to science at this time. My take is they are people that sort-of understand that religion is bogus, but actually cannot be without it end hence invented this surrogate.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.