Intelligence is in the genes, but where?

October 2, 2012 in Psychology & Psychiatry

(Medical Xpress)—You can thank your parents for your smarts—or at least some of them. Psychologists have long known that intelligence, like most other traits, is partly genetic. But a new study led by psychological scientist Christopher Chabris reveals the surprising fact that most of the specific genes long thought to be linked to intelligence probably have no bearing on one's IQ. And it may be some time before researchers can identify intelligence's specific genetic roots.

Chabris and David Laibson, a Harvard economist, led an international team of researchers that analyzed a dozen genes using large data sets that included both intelligence testing and genetic data.

In nearly every case, the researchers found that intelligence could not be linked to the specific genes that were tested. The results are published online in Psychological Science, a journal of the Association for Psychological Science.

"In all of our tests we only found one gene that appeared to be associated with intelligence, and it was a very small effect. This does not mean intelligence does not have a genetic component. It means it's a lot harder to find the particular genes, or the particular genetic variants, that influence the differences in intelligence," said Chabris.

It had long been believed, on the basis of studies of identical and fraternal twins, that intelligence was a heritable trait. The new research affirms that conclusion. But older studies that picked out specific genes had flaws, Chabris said, primarily because of technological limits that prevented researchers from probing more than a few locations in the human genome to find genes that affected intelligence.

"We want to emphasize that we are not saying the people who did earlier research in this area were foolish or wrong," Chabris said. "They were using the best technology and information they had available. At the time, it was believed that individual genes would have a much larger effect—they were expecting to find genes that might each account for several IQ points."

Chabris said additional research is needed to determine the exact role genes play in intelligence.

"As is the case with other traits, like height, there are probably thousands of genes and their variants that are associated with intelligence," he said. "And there may be other genetic effects beyond the single gene effects. There could be interactions among genes, or interactions between genes and the environment. Our results show that the way researchers have been looking for genes that may be related to intelligence—the candidate gene method—is fairly likely to result in false positives, so other methods should be used."

Journal reference: Psychological Science

Provided by Association for Psychological Science

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Eikka
Oct 02, 2012

Rank: 3 / 5 (2)

It probably was a bit silly to assume that a single gene has a huge impact on intelligence, because it means there should be a huge variation in intelligence between people, when in fact most people are very close to the average.

If there was a single intelligence gene, then there's a risk that individuals could easily get such severe mutations that they'd turn into vegetables, which is a bit risky when you don't have that many babies. You'd want them to be at least somewhat intelligent instead of gambling rich and poor with their brains, because if you fail then it's the end of your family line right there.

That's why I think it's reasonable to assume that intelligence is such a diffuse property of the brain, a sum of so many biological factors that it can't easily be changed.

Tausch
Oct 02, 2012

Rank: 1 / 5 (1)

Everything outside blueprints (genes) exist to promote blueprints.
'The accessing process' for 'everything' outside blueprints is key to what humans label 'intelligence'.

The 'access' is throttled or thwarted (controlled).
This control is what makes humans feel most secure.
A control that is detrimental to what is labeled 'intelligence'.

We do not 'know' better.

Roland
Oct 02, 2012

Rank: not rated yet

This must involve multiple genes, and I bet there is an interference mechanism, like with malaria: if you get one copy of a particular type of gene it makes you smarter, but two copies cause autism or some other problem. Otherwise, it would be a simply-selected trait that would increase over time.

Tangent2
Oct 02, 2012

Rank: 3.7 / 5 (3)

Once again, an article that says a whole lot of nothing.. Could be.. May be.. Perhaps.. that is the summation of the answers in this article.

Gotta love these "we still don't know anything about this" articles.

jonnyboy
Oct 02, 2012

Rank: 1 / 5 (2)

"psychological scientist ".....this joke is as funny as it is old.

Egleton
Oct 03, 2012

Rank: not rated yet

Consider Portia a jumping spider. She stalks and eats other spiders.
She has a sophisticated and flexible repertoire of behavioural tools.
She did not go to school.
She was once a single zygote, a single cell. That single cell must have the entire sophisticated "How to Hunt Spiders and not be Eaten" manual built into the single cell zygote.
What better candidate than the genome? How blithe! That is an amazing thought.
Perhaps too amazing. Perhaps the information lies in Quantum space as a Quantum encoded program.

A_Paradox
Oct 05, 2012

Rank: 5 / 5 (2)

One problem with this article and, seemingly, the research it relates to, is that all those involved think there is actually something called general intelligence which can be measured with IQ tests.

I think they will have more success when they start looking at the different 'intelligences' [plural] which constitute the several modes by which the human brain represents its environment and itself.

Howard Gardner, many years ago, posited at least 7 distinct intelligences: linguistic, mathematico-logical, kinesthetic, musical, interpersonal, intrapersonal, and spatial/topological. [I'm pretty sure those are his original list.]

Gardner discussed the idea at length in a book "Frames of mind" and pointed out that societies the world over have traditional ways of acting through these modalities. Furthermore modern brain imaging studies support the idea that various parts of the brain specialise in mediating these different channels.

Tanda
Oct 06, 2012

Rank: 3 / 5 (1)

One problem with this article and, seemingly, the research it relates to, is that all those involved think there is actually something called general intelligence which can be measured with IQ tests.

I think they will have more success when they start looking at the different 'intelligences' [plural] which constitute the several modes by which the human brain represents its environment and itself.

Firstly, Gardner's MI theory is not incompatible with the existence of the g-factor. Secondly, people e.g. Visser have looked at the different "intelligences" and all they have found is that 1) they are mostly intercorrelated, just like IQ subtests are, despite them supposedly being "different" intelligences, and 2) they are correlated with g.

Lurker2358
Oct 06, 2012

Rank: 3 / 5 (1)

Obviously intelligence in humans is as much environmental and congenital as it is genetic.

A significant fraction of intelligence is based not on innate abilities, but rather learned problem solving techniques either through personal experience or through education.

Then you run into "dimensions" of intelligence. Person A is really good in math, but bad at language, while person B is multilingual, but bad at math, while person C might be an exceptional artist or musician, and mediocre at the other things.

Exceptional skills develop as much through environment as innate ability as well. most people couldn't learn music without a teacher, or at least a book, for example.

A tremendous amount of our intelligence is actually "learned problem solving techniques" passed on from previous generations. Pythagoras, Kepler, Newton, Euler, and Groethe: That's innate intelligence. they solved problems which were of a class that could not be reduced to a set of previously solved problems.

Lurker2358
Oct 06, 2012

Rank: 3 / 5 (1)

Howard Gardner, many years ago, posited at least 7 distinct intelligences: linguistic, mathematico-logical, kinesthetic, musical, interpersonal, intrapersonal, and spatial/topological.

Maybe this explains why Real Time Strategy games have such a high skill gap.

I can immediately identify that Starcraft uses at least four of those seven types of intelligence, not counting the fact that music and sound effects are in play as queues in the game, as are words and character/unit/announcer speech, so possibly as many as 6 or 7 of those categories are in play.

Kinesthetic: the physical coordination and muscle memory for hotkeys and the reflexes to react.

Mathematical/logical: most important and must be done for both speed and accuracy on the fly.

Interpersonal: must anticipate the opponent's actions.

Linguistic: only in the sense of queues from production announcers.

Spatial/topological: incredibly important for understanding the value of timing and positioning advantages, etc

Bob_Kob
Oct 07, 2012

Rank: 5 / 5 (2)

The idea that smart parents pass on intelligence through genes I find hard to believe. If anything, it is their education to their children that passes on intelligence, and not something genetic.

Tanda
Oct 10, 2012

Rank: not rated yet

The idea that smart parents pass on intelligence through genes I find hard to believe. If anything, it is their education to their children that passes on intelligence, and not something genetic.

No mainstream intelligence researchers agree with you on that. Are you okay with being a renegade?

A_Paradox
Oct 13, 2012

Rank: not rated yet

Tanda,

Firstly, Gardner's MI theory is not incompatible with the existence of the g-factor. Secondly, people e.g. Visser have looked at the different "intelligences" and all they have found is that 1) they are mostly intercorrelated, just like IQ subtests are, despite them supposedly being "different" intelligences, and 2) they are correlated with g.

I Googled for Visser re Frames of Mind, because I had never heard of her. I came across a rebuttal by H Gardiner. Gardiner asserts that Visser didn't really understand what he/Gardiner is describing.

Gardiner also makes the same obvious point that umpteen thousands of other people have made which is that "g" is most highly correlated with the learning of skills which such "g" tests rely on.

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Intelligence is in the genes, but where?

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