Sunday, November 25, 2007


My goodness, I never imagined that posting a pointer to an article would cause such a kerfuffle! Dennis Bider doth protest too much, methinks but his protestations are a veritable smorgasbord of fallacious argumentation, so it's worth deconstructing. Let's see, we have...

Psychogenetic fallacy:

Flynn is one of those people who helped identify something new and fundamental, and then go on living their lives denying the best explanation because they would like it to be different.

Ad hominem:

I've long since accepted that you won't be converted to the rational outlook. You are a believer; your spiritual well-being rests on whether a certain hypothesis is right.

Straw man:

Stop trying to persuade everyone how unbiased you are

(I have never tried to persuade anyone that I am unbiased. To the contrary, I have been very up-front about my biases.)

I'm not quite sure how to categorize this one:

People form a hypothesis based on what they would like reality to be; not based on what the naked facts tell them; and so they spend decades trying to find out that group selection for lower populations would favor individual restraint in breeding, only to eventually find out that group selection for lower populations leads to cannibalism victimizing especially young females.

How on earth did we get from the genetics of IQ to cannibalism? Argument by gibberish? Non-sequitur? Maybe I'll just call that one the razzle dazzle.

Here's another one that's challenging to categorize:

The Flynn effect is best explained by heterosis

Even if it were true, just because heterosis is the best currently available explanation doesn't mean it is correct. (Ironically, even Bider himself concedes in the post he links to that heterosis is a hypothesis that has not been adequately tested.) The history of science is rife with examples of "best explanations" that turned out to be wrong.

Bider's second comment is the most colossal straw man I have ever encountered (and that's saying something). I think it says something about Bider's insecurity in his position that he feels the need to not only put words in my mouth but thoughts in my brain and feelings in my heart. This one is particularly ironic:

You are a person who has been cursed with an intolerance for other people's suffering.

because people who actually know me consistently tell me that one of my problems is that I don't empathize enough with those around me.


Did desegregation of schools significantly narrow the black-white educational gap? [No, therefore] so much for environment.

This is another straw man, and a truly offensive one. I have never argued (and would never argue) that exposure to people with white skin is the aspect of the environment most responsible for anyone's academic success or lack thereof.

Don Geddis writes:

First of all, the article you link to doesn't support your summary.

My summary was that Flynn believes that "the evidence supporting the hypothesis that intelligence is primarily genetic is weak." I suppose I should have been more careful to distinguish, as Flynn does, between direct and indirect genetic effects. For example, there is no question that skin color is genetic, so if skin color interacts with some environmental factor (like societal bias) to produce some effect one could say that's a genetic influence. Technically it would be true, but I think that would be a perversion of what people generally mean when they say a trait is genetic. It's certainly not what I mean when I say that the evidence that IQ is genetic is weak, and I'm pretty sure Flynn would agree.

Once you get to average, US, major metropolitan levels of education, nutrition, etc., then the IQ variation due to genetics approaches 100%. It is not the case that the smarter kids were read to more, or went to the museum more often, or watched TV less. It is the case that the smarter kids typically had smarter parents.

If this were really true then that would convince me. But I doubt it's really true. In particular, as I have pointed out before, it is impossible to do a properly controlled study to test the effect of race on IQ because it is impossible to control for the societal bias to skin color. The only way to test the hypothesis is to use two racial groups whose IQ's supposedly differ but whose outward appearance is the same, like jewish and non-Jewish caucasians. (You'd need to have both groups raised in similar cultural circumstances, i.e. either all as Jews or all as non-Jews -- and preferably randomized across both cases.) Until you've done a study like that all you have is more pink flamingos.

Here's another Flynn example that is worth pondering: If on the basis of their genetic inheritance, separated-twin pairs are tall, quick, and athletically inclined, both members are likely to be interested in basketball, practice assiduously, play better, and eventually attract the attention of basketball coaches capable of transforming them into world-class competitors. Other twin pairs, in contrast, endowed with shared genes that predispose them to be shorter and stodgier than average will display little aptitude or enthusiasm for playing basketball and will end up as spectators rather than as players.

The trouble with basketball as an analogy to IQ is that height is an easily observable physical trait that obviously has a causal relationship with potential success as a basketball player. Furthermore, height has both genetic and environmental factors. All this is known and uncontroversial. The trouble is, whether or not externally observable and heritable traits are similarly correlated with intelligence is precisely what is at issue here. So there are no lessons to be drawn from the basketball analogy for the matter at hand (except that it is easy to oversimplify).

Just for the record let me make it clear where I stand. I do not dispute that IQ could be genetic. In fact, I think it almost certainly has some genetic component. The question is how much is genetic and how much is environmental, and, importantly, how much is due to complex interplays between genes and environmental and societal factors, and as long as we're being exhaustive, how much is due to the imprecision and multi-dimensionality of intelligence, and how much is just plain random. My position is merely that the currently available data do not justify the conclusion that direct genetic factors (i.e. the direct transcription of DNA into proteins that build bigger or more effective brains) are the dominant factor. Note that I do not say that this is not the case, merely that the data we have don't justify the conclusion. I will also say, as I have said before, that I do think it would be unfortunate if we did have conclusive data to support this position, and that the human condition would on the whole be the worse for it. And people's eagerness to adopt the conclusion that intelligence is genetic, and to vilify anyone who doesn't join them in their prejudice, even in the absence of conclusive evidence does nothing to dissuade me from this belief.


Don Geddis said...

I think you should postpone an investigation of race & IQ (which is how all this started), and just look at genetics vs. IQ within a homogeneous racial group. Like, say, white Swedes. Or Japanese. Or black Kenyans.

Within those groups, there are still huge variations in expressed IQ, even when "corrected" for reasonable environmental influences (like socio-economic background, nutrition, etc.).

Especially when you start talking about public policy, the best predictive theory right now seems to be something like "genetics determines your intelligence potential, and environment determines whether you achieve that potential or fall short."

This is a much better predictor of outcomes, when considering such questions as "what if we hired better teachers for this school?", or "should we buy computers for that kindergarden?"

Your claim that genetics plays only a minor role in IQ (again, throw away the whole racial question) doesn't seem to be supported by the facts. For sure, there is nothing you can measure (at this point in time) or observe about a child's environment that will get you very far to predicting their IQ.

Ron said...

Your claim that genetics plays only a minor role in IQ

I have made no such claim. In fact, I have said the exact opposite: genes clearly do play a major role in the determination of intelligence. (Remember my citing Down Syndrome as an example?) What is not clear is the extent to which the genes that control intelligence are correlated with race. Don't forget that what started this whole debate is a disagreement about whether James Watson was justified in his remarks about Africa and "black employees."

Don Geddis said...

Well, OK. But you did say things like this: I do not dispute that IQ could be genetic. In fact, I think it almost certainly has some genetic component. Which expresses such skepticism about genetic influences that it is heading into just being wrong. Also genetic defects and lack of intelligence isn't nearly so interesting as intelligence potential. IQ averages 100. Various problems (genetic, environmental) can surely cause an individual's IQ to drop to 80 or 70 or 50.

But what, in your opinion, is responsible for the observed variation at the high end? For the kids measured at 100, vs. 120 or 140 or 160?

Once you grant strong genetic influence (especially at the high end), then it's an almost trivial step to correlate it with race, aka historically isolated breeding subpopulations of humans. This is perfectly obvious with non-controversial physical features like skin color, hair color and shape, height, weight, susceptibility to diseases, etc. It would be almost absurd if the genetic component of intelligence were not correlated with race.

As for Watson, your original post in this extensive thread was right on. Watson's published remarks from his book were careful enough, on a controversial topic. But the interview revealed that he's really just a racist bigot, which is too bad. He may be a good scientist in a narrow field, but he's as bad as any layperson when dealing with his own biases. It's sad.

Ron said...

Well, OK. But you did say things like this: I do not dispute that IQ could be genetic. In fact, I think it almost certainly has some genetic component. Which expresses such skepticism about genetic influences that it is heading into just being wrong.

Conceded. There is no question that intelligence has a genetic component. In fact, I'll go even further and say there is no question that is has a genetic component that is correlated with race. BUT (and this is the important bit) we do not yet know the extent to which the correlation between intelligence and race is genetic because existing data has too many confounding factors, and it's extremely difficult (if not actually impossible) to do properly controlled studies. (And no, desegregating schools doesn't count as a properly controlled study, particularly when desegregation looks like this.

As an aside, intelligence is also correlated with myopia and whether or not your mother had broad hips, both of which are almost certainly genetic. Imagine if Watson had said, "There is a natural desire that all human beings should be equal but people who have to deal with employees who don't need corrective lenses and have sexy mothers find this not true". He would have been rightfully pilloried, despite the fact that that statement would have been more grounded in scientific fact than the one he actually made.

denis bider said...

Ron: "And no, desegregating schools doesn't count as a properly controlled study, particularly when desegregation looks like this."

Ron, it's so difficult to argue with you because you just don't hear anything. Sure desegregation can look like this, which is why I previously quoted figures showing that blacks actually do just as well (and in some periods they did even better) in schools that are de facto segregated. As for the photo you linked to, that looks like it's from the 1960s, not today.

I quoted only this snippet from your post because this is what my eyes caught. I am trying not to read the rest. This is too tiring. You are not an open-minded person. Given an argument, I have not seen you once change your point of view. That's annoying and frustrating. If I read more of what you wrote back, then I'll be driven to argue and reply again; but it is pointless, because nothing I say can, no evidence I come up with, can ever change your point of view. If something is inconvenient, you'll just ignore it, or dismiss it in some way. You're on a fixed track and you aren't deviating.

I'm sorry, but this seems so pointless, I'll be unsubscribing from your blog. See you around. Some day. Or not. Who knows.

Ron said...

As for the photo you linked to, that looks like it's from the 1960s, not today.

It is actually from 1957. It's a very famous photo. The black girl in the photo is Elizabeth Eckford and she is still alive.

no evidence I come up with, can ever change your point of view

Not so. I've already described at least one experimental outcome that would convince me that your position is correct. (That's one more than you by the way.)

Given an argument, I have not seen you once change your point of view. That's annoying and frustrating.

Believe me, I know exactly how you feel.

I'll be unsubscribing from your blog.

Oh, dear me, whatever shall I do?

Don Geddis said...

I've been searching for attempts to raise children's IQ scores via training. I recently ran across this description, which includes the quotes:

Most reports indicate that training can only increase scores on IQ tests by about 5 or so points. [...] One of the most intensive attempts to boost intelligence by training was conducted in Yugoslavia by Kvashchev who gave his students training each week for three years in creative problem solving. By the end of the training, the average intelligence level had risen by 8 points. After one year these gains in IQ had been maintained. The crucial question concerning whether these gains are maintained over longer periods of time remains unanswered.

Perhaps there are other, as yet undiscovered, training methods for enhancing IQ scores. But for the moment, it's worth comparing the amount of effort expended in these examples, the net effect (<10 points change), and the typical range of IQs found in a US high school (say, 85-150).

That's not quite the same as saying that IQ is genetic. But it does raise the question of what one could possibly do about it, as a matter of social policy.