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Brain size intelligence fallacy

#11
(2016-Jan-21, 06:52:49)General-Factor analyst Wrote: So no, essentially the brain's capability cannot be credited to it's size (or else whales would the smartest) but rather it's function, organization and network efficiency.


https://www.youtube.com/watch?v=kkbHi2eT5_U
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#12
Which is why humans are smarter than whales because of our brain functions such as cortical organization....
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#13
(2016-Jan-21, 22:41:46)General-Factor analyst Wrote: Which is why humans are smarter than whales because of our brain functions such as cortical organization....


What measure of intelligence did you have in mind when it comes to interspecies comparisons?
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#14
Emil, this one's for you from Dr. Jakob Pietschnig.

Actions
******** 21/01/2016
To: jakob.pietschnig@univie.ac.at

Dear Dr.Pietschnig,


Is brain size a strong factor in explaining individual differences in intelligence?I have also read that instead of using variance among individuals, correlation is a better factor in interpreting data that links brain size to intelligence. Is that true?

RESPONSE:

Dear *********,
simply put: no, it is not a good predictor (I attached a paper which might clarify things for you). Moreover, you must have misunderstood the concept of correlation. Correlation is a method which describes the strength of associations and which may be used to express the amount of explained variance.
Best regards,

Mag. Dr. Jakob Pietschnig, FHEA
Department for Applied Psychology: Health, Development, Enhancement and Intervention
Faculty of Psychology
University of Vienna
Liebiggasse 5, A-1010 Vienna
Austria
Email: jakob.pietschnig@univie.ac.at
Phone: +43 1 4277 47237
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#15
edited. had the wrong numbers before.

Don't be a bird brain. :o)

"Correlation is a method which describes the strength of associations and which may be used to express the amount of explained variance."

This means that the square of r (correlation) = r^2 (variance). Same same. If you are interested in unit increase in X per unit increase in Y, which most people are, then use r, which is what we have been saying.

"simply put: no, it is not a good predictor."

Let's get the matter straight. At one time, the correlation was estimated to be 0.38 (not corrected for range restriction, weighted). A new meta-analysis came out and put the correlation at 0.26 (for healthy subjects, not corrected for range restriction, with missing data filled in with 0 due to the author's conservative approach, weighted). The latter correlation isn't horribly different from the traditional 0.38 value. Either way, we are not dealing with a good predictor.

Presumably what happened is that you saw the .38 correlation that is frequently discussed. And then you saw the 6% variance. And you thought, "6% = 0.06 is a lot lower than 0.38 -- these brain size guys were all wrong!" And so you posted here. But in fact we are not talking about very different values.
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#16
Did you even read any of my posts? Both Dr.Pietschnig and Stuart Richie have stated that brain size is NOT a good predictor. I have already posted their email responses on this thread....it's a fact whether you like it or not.
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#17
(2016-Jan-22, 15:12:23)General-Factor analyst Wrote: Did you even read any of my posts? Both Dr.Pietschnig and Stuart Richie have stated that brain size is NOT a good predictor. I have already posted their email responses on this thread....it's a fact whether you like it or not.


:op

No one here is disagreeing with the reported effect sizes or with the claim that brain size is NOT a "good" predictor.

The original disagreement was with your claim that:

"Variance is definitely more important than correlation."

[Different ways of expressing the same effect size!]

&

"If brain size only explains 6 percent of the variance then it suggests size alone means nothing"

[Misunderstanding of r^2!]

&

"Which proves everything I have been saying. Plays a role in intelligence, not a strong factor and therefore cannot be used to measure individual differences."

But you originally said "size alone means nothing" -- now you have changed the claim to size alone is "not a strong factor".

So we agree that:

1.The association between brain size and IQ is moderate; thus, brain size is not a GOOD predictor.
2.The association was previously overestimated (0.38 versus 0.26, weighted healthy subjects).
3.The "true" association would be higher were corrections for range restriction made.
4.Correlation and variance explained (as r-squared) are just two different ways of looking at the same effect.
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#18
You can't just set aside variance and use correlation as a indicator for it's association with intelligence. Of course variance matters! If brain size as a factor explains very little of variance between individual scores then it's simply is not a good predictor. It simply means brain size has no causal role in intelligence and that may merely share latent traits such as memory capacity with higher order g. The problem as to why many racialists like you fear this is because now you no longer have arm chair logic in explaining racial differences in intelligence. You actually have to go do the work.
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#19
(2016-Feb-28, 22:03:18)General-Factor analyst Wrote: You can't just set aside variance and use correlation as a indicator for it's association with intelligence. Of course variance matters! If brain size as a factor explains very little of variance between individual scores then it's simply is not a good predictor. It simply means brain size has no causal role in intelligence and that may merely share latent traits such as memory capacity with higher order g.


Are you just a moron? r= SQRT(r^2).

"You can't just set aside feet and use inches as a indicator for height. While that tarantula may be three inches high, it's only 1/4th of a foot."

Would someone please ban this clown?
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#20
This is exactly why your papers get nowhere. Good luck publishing your low quality garbage on sites like these while getting rejected by peer reviewed journals year after year.
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