TOT: Heritability of Intelligence

[Sam Plusnet]

Research conducted in Lake Wobegon concluded that all the children were above average.

[Paul]

Here is a theory, as to where brain problems come from.

"But in the past couple of decades, scientists have learned that Mendel’s understanding was incomplete. "

"Sometimes it matters which parent you inherit a gene from — the genes in these cases, called imprinted genes because they carry an extra molecule like a stamp, add a whole new level of complexity to Mendelian inheritance. "

It is used to explain where some abnormal brain developments come from, but it does not address the issue of "melon parents make only melon kids".

We only use 10% of our brains. What controls that "ratio" ?

Paul

[Cursitor Doom]

Yes, but cats would be easy. Just set them before a line of 10 dishes where 9 of them are Whiskas and the other one's Tyne Brand. If they go to Tyne Brand, you know they're developmentally disabled.

[Cursitor Doom]

That would be a *huge* and unjustifiable burden on a developing species. It *must* be there for a reason, even if we don't understand what that is.

[Cursitor Doom]

This is actually rather painful for me. I was abandoned on a rubbish dump in the Scotswood Hall area of Newcastle as a child and adopted by two escaped chimpanzees from a local zoo who raised me and taught me all I know. They did the best they could under impossible circumstances, since they were constantly escaping and getting re-captured, I had a very chaotic childhood. I suspect that accounts for much of my Euroscepticism.

[Rod Speed]

It is very far from clear that that is actually true.

It's actually just an urban myth.

Those with only 10% of their brain left due to trauma are nothing even remotely like indistinguishable from the rest of us even after years of adjustment.

Like need if it was true.

Not necessarily.

May well be that it gave a survival advantage in the past.

[Paul]

You can't use the fMRI photos as an indicator, as they measure blood flow and not brain activity. and a web page I was reading a day ago, someone who might have claimed to be able to "read what you were thinking with fMRI", after having examined candidates three months after an initial scan, no longer thinks this is true. The correlation was poor, on uni students measured three months apart.

I don't know what measures brain activity. You can certainly fit an electrode cap (EEG), but I don't think that gives 3D info necessarily.

You could do a CT:PET scan of the brain (two passes), and FDG sugar, as the uptake of sugar might indicate a portion of brain that is working. And that causes a different color on the second pass scan. The scans are basically subtracted, to improve contrast from the contrast chemical (FDG). I had that done to shoot a 10 second video of my heart (but it's possible the same procedure would work on a brain). You're not allowed any sugar the day before ("24 hour keto diet").

There's an article here on MEG, and you can see how each technique is "rather stretched".

So while we can bust the myth:

The problem remains that:

"The hosts used magnetoencephalography and fMRI to scan the brain of someone attempting a complicated mental task, and found that as much as 35% was used during their test. "

With some error bars on the 35%.

*******

And these are the electrical signals you get off your forehead, with a couple electrodes (Ag/AgCl plus electrode cream). About

1/10th the amplitude of your heart pulse, but at quite a different frequency from your heart. Your pulse might be 1mV (can be seen with a Tek 7000 with the diff module plugged in and a scope probe in each hand), while the electrodes on your head are around 100uV (not measured with the Tek). For brain waves, battery operated equipment is best :-)

At least the second link, the image looks like it might have come from real equipment, and not just an artistic squiggle. That's surprisingly hard to control, so if you were thinking "could I play a tune on that?" the answer is no :-)

As you would expect, the squiggle never stops.

Paul

[R Souls]

That, and your imbecility.

[The Natural Philosopher]

Well whatever IQ tests *do* measure, was found by the military as being an excellent indicators of 'officer material', by industry as excellent indicators for board level management, and by universities as an excellent indicator for suitability for high level academic education.

The people who say there is no such thing are those for whom that statement is self evidently true, in my experience.

[The Natural Philosopher]

I attended a talk by a roboticist, SHE said 'we found out what the other

90% is used for when we tried to get our robot to *walk on two legs*'.

Apparently *not falling over* takes a huge amount more computational power than deciding whether to go to McDonalds or Burger King

[Cursitor Doom]

Or Lefties.

[Cursitor Doom]

You're the ghost of Dave Plowman and ICTFP.

[Jethro_uk]

Bipedal walking is essentially controlled falling.

It must confer some considerable advantage, given the sacrifices it requires as a species.

[Jethro_uk]

So one conclusion is intelligence isn't needed for those activities ?

I didn't say there is no such thing as "intelligence". What I did say is whatever it may be lacks definitive objective criteria.

[Cursitor Doom]

Yes, but what, though? I initially thought 'so you can reach fruit on trees more easily' but on further reflection, that doesn't add up.

[The Natural Philosopher]

Is there a difference?

[The Natural Philosopher]

What it does is allow locomotion to be separate from tool handling. And allow good climbing skills

No other species can run AND throw a spear.

[The Natural Philosopher]

No, one conclusion is that whatever IQ measures which is normally called high intelligence IS required for those positions

The definition is 'scores well in IQ tests'. Note the Q. It means 'quotient'.

No one denies a labrador has intelligence. Just not a lot really, as anyone who has trained one knows.

[Rod Speed]

Paul [e-mail] wrote

Nothing does on the question of what percentage of the brain ever gets used over a lifetime.

And even if it did, that doesnt tell you which parts of the brain never get used over an entire lifetime.

Not necessarily, and not over a lifetime either.

No evidence that sugar use indicates brain actually used at all.

And that's just the one test, says nothing useful about the entire lifetime.

But its far from clear what the squiggle actually indicates.

[JNugent]

QUOTE: Scientists have investigated this question for more than a century, and the answer is clear: the differences between people on intelligence tests are substantially the result of genetic differences. ENDQUOTE

QUOTE: We found that high intelligence is familial, heritable, and caused by the same genetic and environmental factors responsible for the normal distribution of intelligence. High intelligence is a good candidate for "positive genetics" - going beyond the negative effects of DNA sequence variation on disease and disorders to consider the positive end of the distribution of genetic effects. ENDQUOTE