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Study shows big-brained people are smarter

Thread ID: 18705 | Posts: 7 | Started: 2005-06-18

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kminta [OP]

2005-06-18 01:47 | User Profile

[I]Those of us interested in debates related to [B]The Bell Curve[/B] will immediately recognize the significance of this article. The general public probably won't.[/I]

[B][URL=http://www.scienceblog.com/cms/node/8206]Study shows big-brained people are smarter[/URL][/B]

People with bigger brains are smarter than their smaller-brained counterparts, according to a study conducted by a Virginia Commonwealth University researcher published in the journal “Intelligence.”

The study, published on line June 16, could settle a long-standing scientific debate about the relationship between brain size and intelligence. Ever since German anatomist and physiologist Frederick Tiedmann wrote in 1836 that there exists “an indisputable connection between the size of the brain and the mental energy displayed by the individual man,” scientists have been searching for biological evidence to prove his claim.

“For all age and sex groups, it is now very clear that brain volume and intelligence are related,” said lead researcher Michael A. McDaniel, Ph.D., an industrial and organizational psychologist who specializes in the study of intelligence and other predictors of job performance.

The study is the most comprehensive of its kind, drawing conclusions from 26 previous – mostly recent – international studies involving brain volume and intelligence. It was only five years ago, with the increased use of MRI-based brain assessments, that more data relating to brain volume and intelligence became available.

McDaniel, a professor in management in VCU’s School of Business, found that, on average, intelligence increases with increasing brain volume. Intelligence was measured with standardized intelligence tests, which have important consequences on peoples' lives, such as where they’ll go to college or what kind of job they get. Critics have called the tests inaccurate or irrelevant to the real world, he said.

“But when intelligence is correlated with a biological reality such as brain volume, it becomes harder to argue that human intelligence can’t be measured or that the scores do not reflect something meaningful,” said McDaniel.

As an industrial and organizational psychologist, McDaniel works with employers to screen job applicants and measure their performance. He said employers will appreciate his findings because intelligence tests are the single best predictor of job performance.

“On average, smarter people learn quicker, make fewer errors, and are more productive,” McDaniel said. “The use of intelligence tests in screening job applicants has substantial economic benefits for organizations.”

Before MRIs, scientists often used external skull measurements or waited until a person died to estimate brain size. The external skull measurements were only approximate estimates of brain volume.

From Virgina Commonwealth University

Ponce

2005-06-18 02:02 | User Profile

BULL bigger brain does not mean that you are smarter.

Many cases have I read were people are missing up to 75% of their brain and are no different than others.

I don't know anything about medecine but do know that when one part of the brain goes kaput then another side takes over and it keeps on going.

We are just going into learning what the brain is and it will be a while fefore we fully understand it.

Angler

2005-06-18 08:56 | User Profile

I don't doubt that there's at least some correlation between brain size and intelligence, but size alone almost certainly isn't the whole story. For example, I've read that postmortem inspection of the brain of at least one exceedingly brilliant person -- I'm pretty sure it was the famous mathematician Carl Friedrich Gauss -- revealed a size only slightly above average. However, Gauss' brain showed much more extensive convolution than is seen in a typical brain -- i.e., there were a lot of folds in the cerebrum. That would tend to increase within-brain surface area and facilitate connectivity between different brain regions.

Happy Hacker

2005-06-18 12:14 | User Profile

[QUOTE=Ponce]BULL bigger brain does not mean that you are smarter.[/QUOTE]

Size isn't the only factor, but to deny size is a factor goes against reason and evidence. Smart people with smaller brains make up for a less size with more convolution.

RowdyRoddyPiper

2005-06-18 12:53 | User Profile

If it was possible to have the same level of intelligence with a smaller brain, natural selection would select the smaller brain because it consumes less energy, less weight to carry around, is a smaller target for spears etc etc.

There has to be some advantage (on the average) to having a bigger brain, or what would be the point of growing one?

Angeleyes

2005-06-21 04:49 | User Profile

[QUOTE=Happy Hacker]Size isn't the only factor, but to deny size is a factor goes against reason and evidence. Smart people with smaller brains make up for a less size with more convolution.[/QUOTE] I think Angler is on to something. I was taught in HS science that a relatively smoothe brain was bad, and one with lots of folds (hence lots of surface area?) was one that tended to make you smarter.

That was back in the 70's folks were teaching that.

Happy Hacker

2005-06-21 05:50 | User Profile

[QUOTE=Angeleyes]I think Angler is on to something. I was taught in HS science that a relatively smoothe brain was bad, and one with lots of folds (hence lots of surface area?) was one that tended to make you smarter.[/QUOTE]

You are correct. The surface area or convolutions is just an indirect way to measure brain complexity.