Post: #1

http://news.yahoo.com/tiny-gene-change-a...20119.html

Quote:An international team of scientists said Sunday the largest brain study of its kind had found a gene linked to intelligence, a small piece in the puzzle as to why some people are smarter than others.
A variant of this gene "can tilt the scales in favour of a higher intelligence", study leader Paul Thompson told AFP, stressing though that genetic blessings were not the only factor in brainpower.
Searching for a genetic explanation for brain disease, the scientists stumbled upon a minute variant in a gene called HMGA2 among people who had larger brains and scored higher on standardised IQ tests.
Thompson dubbed it "an intelligence gene" and said it was likely that many more such genes were yet to be discovered.
The variant occurs on HMGA2 where there is just a single change in the permutation of the four "letters" of the genetic code.
DNA, the blueprint for life, comprises four basic chemicals called A (for adenine), C (cytosine), T (thymine) and G (guanine), strung together in different combinations along a double helix.
In this case, the researchers found that people with a double "C" and no "T" in a specific section of the HMGA2 gene had bigger brains on average.
"It is a strange result, you wouldn't think that something as simple as one small change in the genetic code could explain differences in intelligence worldwide," said Thompson, a neurologist at the University of California at Los Angeles.
The discovery came in a study of brain scans and DNA samples from more than 20,000 people from North America, Europe and Australia, of European ancestry.
People who received two Cs from their parents, a quarter of the population, scored on average 1.3 points higher than the next group -- half of the population with only one C in this section of the gene.
The last quarter of people, with no Cs, scored another 1.3 points lower.
"The effect is small," said Thompson, but "would be noticeable on a (IQ) test ... (it) may mean you get a couple more questions correct.
"It wouldn't be an enormous change. Even so, it would help our brain resist cognitive decline later in life."
It is generally accepted that genes, a good education and environmental factors combine to determine our intelligence.
"If people wanted to change their genetic destiny they could either increase their exercise or improve their diet and education," said Thompson. "Most other ways we know of improving brain function more than outweigh this gene."
He added there were ethical safeguards and laws in place to guard against the abuse of genetic information.
The research, published in Nature Genetics, was conducted by more than 200 scientists from 100 institutions worldwide, working together on a project called Enigma.
Thompson said other studies have implicated some genes in IQ, but this was the first to link a common gene to brain size.
The team found that every T in place of a C represented a 0.6 percent smaller brain -- equal to more than a year's worth of brain loss through the normal ageing process.
Asked to comment on the research, Tom Hartley, a psychologist at Britain's University of York said he was "a little wary of thinking in terms of a gene for intelligence.
"There are undoubtedly a lot of things that have to work properly in order to get a good score on an IQ test, if any of these go wrong the score will be worse."
But he said it was "fascinating" to find that such small genetic changes could affect the size of critical structures such as the hippocampus, the brain's memory centre.
"Given the importance of the hippocampus in disorders such as Alzheimer's disease these could turn out to be very significant findings," said Hartley.
John Williams, head of neuroscience and mental health at the Wellcome Trust, a British charitable foundation which backs biomedical research, said the findings paved the way for further research into "structural changes" which occur in disorders such as dementia, autism and schizophrenia.

Sorry, critical theorists/social constructivists, but science has marched on without you; hopefully academia will follow suit as well and within the next twenty years or so, your ideas will be relegated to the reaches of the Internet reserved for Flat Earthers and Holocaust deniers.

Post: #2

The heritability of IQ is usually quoted as somewhere between .7 and .8, but only as long as it's measured in a community with widespread access to education, healthcare, and adequate nutrition. The genetic influence on intelligence is much less strong in places with a lot of poverty because things like lack of education, childhood disease, and nutritional deficiency can result in developmental delay and lower someone's IQ significantly below their genetic potential.

This is a cool discovery, but I doubt any one gene is going to be found that's responsible for a great deal of the variation in intelligence. All the evidence to date supports the idea that intelligence is a multifactorial trait influenced by a lot of different genes.

Post: #3

I've always believed it to be polygenic based on scientific evidence as well, but perhaps this one gene plays the most important role out of all of them.

Post: #4

2.6 points is still 1/40th advantage

Post: #5

(04-17-2012 12:57 AM)porcupine Wrote:  I've always believed it to be polygenic based on scientific evidence as well, but perhaps this one gene plays the most important role out of all of them.

The thing is, science reporting in the popular press is generally so shitty and overhyped that I can't really buy that they've actually made a profound discovery without seeing the original study first. It's possible that they've discovered a gene with an exceptionally large influence on intelligence, but it's more probable that it's a more pedestrian piece of research that's been sexed up by a lay reporter with questionable scientific literacy.

Post: #6

Fair point.

Can't keep track of how many times they've "found a cure" for cancer.

Post: #7

Two titans in the field of intelligence just a published a summary of the current research in the field:
http://www.nature.com/mp/journal/vaop/nc...4105a.html

Post: #8

Basil, I don't mean to sound like I'm nitpicking but while these two distinguished gentlemen are prominent researchers in the field, I don't think they should be characterized as "titans". I mean, they're not exactly Newton and Leibniz, or Bohr and Einstein. Some fields of research don't really have titanic achievements, and therefore don't have any titans, though they may have leading and prominent experts which these two undoubtedly are.

The reason I'm bothering to make this point is that I think there is a general misapprehension of the extreme differences between different scientific fields in terms of the quality of their practitioners and the overall quality of achievement in the field. To most people it's all "science" and so the preeminent specialist in the given field must be a "scientific genius" or at the very least a "titan". But it doesn't work like that -- some scientific fields are in their infancy and their practitioners, even the best of them, have relatively little to boast of. Terms such as "titan" should be reserved for men (or women, LOL) who have made a contribution that is of great and lasting value on an absolute scale, not just relative to the field they're in.