Why IQ?

[The Invisible Gorilla]

Not really. If you have white kids in a dysfunctional enviroment, then seperate their sibling and put them in a good enviroment you will see what the French studies shows. Namely that the dysfunctional enviroment brings down the IQ a bit, while the good enviroment brings it up a bit. The sum of that are the 14 point IQ increase. That's because whites with a normal 100 IQ have a larger variability than blacks with a 90 IQ, when the enviromental factor is 20%. 

 

A standard deviation is not 'a bit'. Could you cite some evidence?

 

Also, you hit on one of the issues regarding heritability. Saying the 'environmental factor is 20%' is neither valid nor useful. Joseph (2015) can explain much better than I can so have a look at the hypothetical situation he presents, below.

 

‘As an example of how heritability estimates do not measure the “strength” or “magnitude” of genetic influences, imagine a country in which all citizens (100 percent) carry the gene predisposing them to favism, a disease marked by the development of hemolytic anemia. Favism is caused by an inherited deficiency of glucose-6-phosphate located on the X chromosome, combined with the consumption of fava (broad) beans or the inhalation of fava bean pollen. In other words, both “beans and genes” are necessary for favism to appear. Let us then imagine that 3 percent of the citizens, all of whom are of course genetically predisposed to develop favism, consume fava beans and are subsequently diagnosed with favism. In this case, because all citizens carried the gene but only some ate fava beans, all favism variation in the population would be caused by environmental factors (fava bean exposure), and the heritability of favism therefore would be zero (0.0). Even though favism heritability would be 0 percent in this example, it obviously would be mistaken to conclude that genes play no role in developing the disorder, or that the genetic influence was weak or irrelevant. A genetic predisposition is, in fact, a prerequisite for developing favism.

 

On the other extreme, if all citizens ate a diet that included fava beans but only some carried the gene, all favism variation would now be caused by genetic factors (carrying or not carrying the gene), and the heritability of favism would be 100 percent (1.0). As we see, heritability estimates assess variation as opposed to cause, and do not indicate the “strength” of the genetic influence (Moore, 2013).2

 

As another example, imagine a society where everyone (like MZ twin pairs) is born with identical genotypes. In such a society, all variation in intelligence and behavior would be caused by environmental factors, meaning that the heritability of all behavioral characteristics, psychiatric disorders, medical conditions—basically everything—would be zero. Once again, population variation and cause are different concepts.’ (p. 79)

 

References

 

Joseph, J. (2015). The trouble with twin studies: A reassessment of twin research in the social and behavioral sciences. New York: Routledge.

[rosencrantz]

Saying the 'environmental factor is 20%' is neither valid nor useful.

 

How so? 

 

so have a look at the hypothetical situation

 

Nah. 

[Zoey141]

Isn't EQ being touted as the next big thing? 

[Matthew Moran]

Isn't EQ being touted as the next big thing? 

 

There's apparently a huge lack of evidence for EQ. Podcast FDR 3228, "Why Emotional Intelligence is Nonsense" goes over this just in case anyone is interested. 

[Caley McKibbin]

All IQ tests are fundamentally biased by having problem types whose solutions can be more or less familiar.  However, IQ deniers never suggest any alternative because their arguments are a smokescreen for a hostility to their own intelligence being revealed and resulting in them having second rate status, or in some rare cases guilt about the bias working to their advantage.

 

Furthermore, the effect of intelligence on success is largely suppressed by an anti-meritorious academic system from K to university and employment market.  Schools already practice such absurdities as hiding high school exam scores from transcripts, prohibiting fail grades from being given and shirking the mandate in the Education Act to provide special education to students with special ability.  Post-school you then have, at least, nepotism and a glass ceiling where no one moves up unless someone higher dies, quits or is fired.  I can't quantify the lives ruined by frustration and ultimately depression like mine was.  I can only say +1 to the category of high IQ and unhappy because of low IQers systematically preventing my ability from being used rather than because IQ is an inaccurate measure of ability.

[Caley McKibbin]

A standard deviation is not 'a bit'. Could you cite some evidence?

 

Also, you hit on one of the issues regarding heritability. Saying the 'environmental factor is 20%' is neither valid nor useful. Joseph (2015) can explain much better than I can so have a look at the hypothetical situation he presents, below.

 

‘As an example of how heritability estimates do not measure the “strength” or “magnitude” of genetic influences, imagine a country in which all citizens (100 percent) carry the gene predisposing them to favism, a disease marked by the development of hemolytic anemia. Favism is caused by an inherited deficiency of glucose-6-phosphate located on the X chromosome, combined with the consumption of fava (broad) beans or the inhalation of fava bean pollen. In other words, both “beans and genes” are necessary for favism to appear. Let us then imagine that 3 percent of the citizens, all of whom are of course genetically predisposed to develop favism, consume fava beans and are subsequently diagnosed with favism. In this case, because all citizens carried the gene but only some ate fava beans, all favism variation in the population would be caused by environmental factors (fava bean exposure), and the heritability of favism therefore would be zero (0.0). Even though favism heritability would be 0 percent in this example, it obviously would be mistaken to conclude that genes play no role in developing the disorder, or that the genetic influence was weak or irrelevant. A genetic predisposition is, in fact, a prerequisite for developing favism.

 

On the other extreme, if all citizens ate a diet that included fava beans but only some carried the gene, all favism variation would now be caused by genetic factors (carrying or not carrying the gene), and the heritability of favism would be 100 percent (1.0). As we see, heritability estimates assess variation as opposed to cause, and do not indicate the “strength” of the genetic influence (Moore, 2013).2

 

As another example, imagine a society where everyone (like MZ twin pairs) is born with identical genotypes. In such a society, all variation in intelligence and behavior would be caused by environmental factors, meaning that the heritability of all behavioral characteristics, psychiatric disorders, medical conditions—basically everything—would be zero. Once again, population variation and cause are different concepts.’ (p. 79)

 

References

 

Joseph, J. (2015). The trouble with twin studies: A reassessment of twin research in the social and behavioral sciences. New York: Routledge.

More completely dissected, it is a failure to understand marginal logic.  All required contribution types of a result simultaneously have a 100% marginal effect strength on that outcome.  Ergo, given that having genes is categorically required to have any trait while being conventionally classified as "alive", the effect strength of genes is always 100%.

 

Now let's get to a more useful question: how much does any specific gene affect IQ?  To answer this you firstly need to specify a substitution, such as copyA -> copyB.  Secondly, you need a crapload of clones to try every possible combination of copyB + every possible combination of every other gene.  1 million years later you know what difference switching from copyA to copyB makes.  Or you could make a perfect model of the universe in a computer and leave a sim running for a while.  That might take less than 1 million years.

 

If you feed a kid more, he won't grow taller, just fatter, but if you don't feed him enough he may not be as tall as he would otherwise.  Similarly, circumcision, lack of breastfeeding, spanking, and neglect can negatively impact a child's IQ, but there isn't anything we know of that boosts their IQ that much.

 

Neither are really true.  On the face of it, the mechanisms for both are physically accessible, so there is a way to modulate them in both directions.  IQ can be boosted by innumerable means of stimulants.  Overeating does increase height by altering hormones.  Insulin-like Growth Factor 1 is affected by insulin circulation.  It's possible that the height increase in the past 100 years is to any extent a result of eating "too much" rather than a transition from being fed "too little" to being fed "enough".  I.e, the threshold effect is speculation.