Jason Malloy on P.Z. Myers

What do you mean with the above? Again, I don't think SES captures the whole picture as a measure. It also depends on the study. I can't say without having read it. Have you? Not just the lines cited by Malloy but the entire study?

This is new territory for me and I haven't yet had much time to do the reading required to give an informed opinion, especially since I'm venturing from environmental epi into psychological epi now. From some literature searches I've performed on pubmed, scopus and scholargoogle I have a suspicion that Malloy might be cherrypicking the data, but I need to do more reading before I can give a good opinion on this.

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Ah, worked for me this time.

The guy who wrote the blog seems rather optimistic, since he appears to expect that a small number of 'intelligence genes' will soon be able to account for the differences. It might turn out to be alot more complicated than that.

With proteins, any number of amino acids difference can potentially impair function, and considering the countless proteins that function and interact throughout development and later on in the CNS, I think we might within a few decades be swamped with more correlations between cognitive function and allele frequencies than you can shake a stick at.

A problem is that poorly understood data is heaven for cherrypickers with an agenda. I personally find actual studies much more telling than bloggers with agendas, as a critical evaluation of the data and a sober reflection over what has been shown is essential.

Peter

That particular quote actually isn’t from any particular study; it’s from an interview with Abigail Thernstrom analyzing this issue. The interview can be found here: http://www.pbs.org/wgbh/pages/frontl...hernstrom.html

When I linked to the chart showing the IQ difference to still exist even when SES is equal, you said that the IQ difference still might be caused by some sort of socio-economic inequality that differs from whatever way SES was measured for that chart. You mentioned education and job status as two possibilities. But what I’m saying is that if you’re going to attribute the IQ difference to a socio-economic inequality, it has to be a socio-economic inequality that puts black families at a disadvantage compared to white families even when they are earning seven times more money, since the achievement gap still exists in that situation.

So, if it’s caused by job status, do you think job status tends to be better in white families that earn $10,000 per year than in black families that earn $70,000? How about education? It seems kind of dubious that there would be any socio-economic measurement by which black families with a 70K annual income are, on average, less privileged than white families with a 10K one.

This is why I said we shouldn’t consider this analysis to constitute proof. All it shows is that there’s a way to test the genetic hypothesis, and that this first bit of data is what we’d expect to see if the genetic hypothesis were true.

I’ve heard about a few other studies that turned up things like this, but they might take a little while for me to find. I can look for them if you’d like me to, though.

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I'd expect to see many conflicting results even if the genetics hypothesis is true.

That said, while it's fun and interesting to calculate data like that, I do hope that you realize that the blog "analysis" doesn't even live up to the lowest standards of evidence. I haven't been able to devote much time on it, but I still noticed several problems that I'll quickly mention below:

* Since mankind evolved in Africa, the genetic diversity is exceedingly high on that continent, even between closely located groups. So that the blogger simply assumed that the allele frequency of nigerians is representative of blacks in general, I have to say, borders on inanity.

* The study the blogger used, measured IQ differences of schizophrenias, their siblings and healthy controls, and correlated them to those alleles, because they're on a scizophrenia susceptibility gene! It should have been obvious for the blogger to consider whether the data can even be used for his purpose, as the alleles might not have the same effects in healthy individuals as in schizophrenias.

* 80% of the schizophrenia group were on antipsychotic medicine. Wikipedia-> "From a subjective perspective, antipsychotics heavily influence one's perceptions of pleasurable sensations, causing a severe reduction in feelings of desire, motivation, pensive thought, and awe. This does not coincide with the apathy and lack of motivation experienced by the negative symptoms of schizophrenia. Detrimental effects on short term memory, which affect the way one figures and calculates (although this also may be purely subjective), may also be observed on high enough dosages. These are all the reasons why they are thought to affect "creativity"."

*The gender ratios between the groups differs significantly. (Might not have had a big impact, but worthy of mention anyway)

* The Discussion section in the schizophrenia study says that allele rs760761 was their most consistant association with the IQ scores, but also mentions another study using entirely healthy individuals where the allele was associated with impaired brain electrophysiology, so obviously more research is needed to know what is going on.

* The blogger could have interpreted other results as succes as well. Notice that the calculated asian and white IQ scores doesn't differ, but he doesn't consider that a failure, he just says that other genes will fill that gap. These kinds of ad hoc interpretations are typical for people with strong biases. Had the white IQ been higher than the other 2 scores I'm sure he'd have exclaimed "success" as well, and another "success" would have been if the asian one had been higher than the other groups. I'm sure lots of combinations of results could have met his criteria of success. Also, had he not been able to interpret his findings as "success", do you think he would publish the results? That's the danger of agendas, no matter how reality turns out, it will be interpreted according to bias, accepted if the data is in line with the bias, erroneous assumptions will be made, ignoring obvious factors, no critical evaluation of the data or understanding of the sources, only the best looking results will be published, and most of the people with the same bias will lap it up without checking it.

These are just some quick points I thought was important to make. I'm sure if I had more time, I could have read the study more thoroughly and stated the problems more clearly.

If the above blog is the best you could present, I really think that you most of all need to find those studies for your own sake. But I'd be interested too of course if you find something good, as you've peaked my interest in the subject with the transracial adoption study.

Peter

Can you tell me where it is. Because as far as I can see, this story only talks about the test-scores in SAT-tests in children in general, not divided over SES.

And here's my problem again. I don't doubt that job status will be better with parents with more than 70.000 compared to parents with less than 10.000. But I'm not sure what it tells us exactly. If there are differences in the jobs with which the group of black parents and white parents make money for example, this may have a severe impact on the significance that is placed in the child's home on academic achievement, hence impacting quality of study and hence impacting IQ. There may be a significant difference in the composition of black families or white families in both groups, or between education levels of mother or father in both groups. This can all be tested, just as much as a genetic difference can. But none of those factors are necessarily captured well be SES.

edited to add: I'll get to the adoption study somewhere next week. I think I'll get the articles Monday, but I don't know when I've got time to read them yet.

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Originally Posted by Aggie

Well, if mental chronometry tests aren’t measuring that, they aren’t doing what they’re designed to do. I guess that’s possible, but it’s a fairly well-established testing method,

Would it be the only well-established method not to measure what it's meant to measure? I doubt that. So many things are measured indirectly. (I've just had a little exercise on genetic diversity and migration between populations. That seems one great example of a subject where a well-established metric rarely measures what it's supposed to measure)

and the results are always pretty consistent with those of a normal IQ test. That would make sense if it’s measuring synapse speed (which is the main neurological factor that influences IQ), but I’m not sure how you would explain this otherwise.

How did they establish that synapse speed is the main neurological factor that influences IQ? Let me guess: by correlating mental chronometry results with IQ scores? (Ok, it's "common sense" that synapse speed would influence IQ, but as we all know, the world doesn't always conform to common sense)

I don't know how I'd explain the correlation otherwise, but that doesn't mean it's not a pirates cause global warming correlation. (I think I enjoy hole-finding way too much. Maybe this is where I should stop doing it )

As J. Philippe Rushton pointed out on NPR here, there are close to 100 different ways of measuring intelligence, and they all correlate with each other pretty well. So whatever ways that you think the tests are inaccurate, you’d need to either come up with a type of inaccuracy that can affect them all in exactly the same way, or explain why multiple confounding factors would all have the same effect.

As I've said, I'm not interested enough in the topic to do the necessary reading. So I'm afraid I'm not going to come up with such an inaccuracy.

(Yes, blame me for laziness, but I've stressed and will keep stressing that I consider this debate an enjoyable exercise in critical thinking and leave the positive arguments for others )

Nevertheless, Rushton may have pointed out that there are so many different ways of measuring intelligence, but he didn't really reassure us that they correlate because they all truly measure intelligence. While I see your point IF these tests are independent ways of measuring the same thing, I'm still not entirely sure that the same factor(s) couldn't be messing with all of them.

For normal IQ tests, the stereotype threat possibility definitely doesn’t explain why scores would differ between 100% African children raised by white families and mixed-race children raised by white families, especially when the mixed-race children believe themselves to be 100% African. I don’t think the stereotypes are any different—as I said before, 50% African people such as Obama are still just thought of as being “black”—but even if the stereotypes are different, people aren’t able to be affected by stereotypes of a heritage that they don’t know they have.

That is probably right. Which means that if stereotype threat is a contributing factor, it's certainly not the only one.

Originally Posted by Aggie

In order for prenatal factors to explain why a group that half had African fathers and Caucasian mothers, and half had Caucasian fathers and African mothers, had an average IQ exactly halfway between a group of 100% Africans and a group of 100% Caucasians, prenatal environment would have to be the only environmental factor contributing to the IQ difference.

Can't you say the exact same thing for genetic factors?

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You’ve given me a lot to reply to here again, so I’ll have to split my post up a little.

Plindboe: There’s a study I’d heard about that focused specifically on the connection between IQ and specific genes that vary with race, but it took me a little while to find it. Here it is, though: http://homepage.mac.com/harpend/.Pub...jbiosocsci.pdf

This study is about the genetic basis for intelligence in Ashkenazi Jews, who have the highest average IQ of any known ethnic group. So it doesn’t specifically answer the question of what’s causing the IQ difference between Africans and Caucasians, but it does help answer the more general question of whether genes play a role in the IQ differences between races.

Tomk80: It’s near the bottom of the PBS article, when the interviewer asks Thernstrom about why higher levels of income and education in black parents aren’t translating to the next generation.

I’m not sure whether the two remaining possibilities you mentioned, which aren’t captured by measuring SES, have been tested or not. What I know for sure is that when the APA conducted their analysis of this issue that I linked to earlier, they tested every potential environmental factor that they thought could be making a difference, and ultimately reached the conclusion that nobody has yet come up with an environmental explanation for this. (Although they didn’t think there was specific support for a genetic hypothesis either—this was the 1990s after all, and the human genome hadn’t been sequenced yet.)

So it’s possible that the two possibilities you mentioned haven’t been tested yet. If they really haven’t been, and they have the potential to explain the IQ difference, then these are potential environmental hypotheses that deserve to be studied also.

To get back to the point I made in my OP, though, I don’t think this provides any justification for P.Z. Myers acting as though the genetic hypothesis is not an acceptable one, or that the IQ difference is fully explainable through things like income level or discrimination, which have already been shown to not be causing it.

Sinande: I don’t have Ferahgo’s psychology textbook anymore, but here’s one paper that talks about synapse speed (aka nerve conduction velocity) as a determining factor in intelligence: http://www.springerlink.com/content/v003708m0u002115/ . I can probably find some more examples of this, if you need to see them.

I’m not sure about what you’re asking about genetic factors here. Are you asking why the IQ difference would be greater between the kids with two black parents and the mixed-race kids, than it is between the mixed-race kids and the 100% white kids? I’m not sure what the answer is to that, but it might have something to do with the fact that most African-Americans in the U.S. are not 100% African to begin with. Even the people with two black parents in this study would have averaged something like 35% white—I’m not sure what the exact rate of racial admixture is, but I know it’s somewhere around that.

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Thanks, it looks interesting. I'll bookmark it and read it when I can. The next course I'm starting on seems very compressed, so I won't have much, if any, spare time for about a month.

Peter

I teach in a lower socioeconomic school. My observations can be dismissed as anecdotal, however they are direct observations. I am not basing my judgement purely on something I read about.

That being said, I think what gets neglected a lot in these studies is parental attitude toward education. Many of these children were raised by teen mothers, who did not complete their own education and do not have the experience that educated families do to guide their children. They don't have very good role models IOW.

I see a number of promising minds wasted by culture. If your expectation is low that becomes a self fulfilling prophecy. I've heard children say, "I'm Mexican" as if that excused or explained anything.

As a teacher, if I accepted that as an excuse what would be the point of education at all? At worst, I would be a bigot if I accepted that.

I am not saying every student regardless of color is an A student, but they are all capable of achieving a college education.

I say kudos to Myers in not being hasty to draw a conclusion on something as complex as intelligence. I believe it is gross oversimplication to believe you have captured intelligence on a standardized test.

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In some respects, science has far surpassed religion in delivering awe. How is it that hardly any major religion has looked at science and concluded, "This is better than we thought! The universe is much bigger than out prophets said, grander, more subtle, more elegant. God must be even greater than we dreamed"? Instead they say, "No, no, no! My god is a little god, and I want him to stay that way." _-Carl Sagan

People’s attitudes towards education probably make a difference too, but when you look at the data that there is about this topic, I don’t see how that can be an adequate explanation for all of it. You have to remember that in the Minnesota Adoption study I described, kids with one black and one white parent are performing better than kids with two black parents, even when they don’t know that one of their parents is white. A person can’t use the excuse “I’m 50% black and 50% white, so I should score in between those two groups” if they aren’t aware that this is their ancestry at all.

And as far as adoptive parents are concerned, both groups are the same—they were both raised by middle-class white families. If this IQ difference is caused by some sort of environmental or cultural difference, it definitely isn’t one that can be identified so easily.

P.Z. Myers is being hasty about this topic in the opposite direction. He’s convinced that the IQ difference can be explained by nothing but a few very simple environmental factors, which happen to have already been ruled out as possible causes, but he refuses to acknowledge that they have been even when someone points this out to him. If you want to say there isn’t enough evidence yet to conclude that the difference is genetic, that’s fine; that’s the same thing that the APA concluded. But what Myers is claiming goes far beyond this, and he also apparently won’t tolerate any viewpoints which claim otherwise.

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