There is an impression that your IQ score is a fixed thing that you're born with, but in reality you can "study" for the IQ test and get better scores at it. There is also the whole issue that IQ scores have been rapidly rising in the past few decades.

This might just mean that IQ score merely acts as a proxy for socioeconomic status and education level and a bunch of other factors, and it doesn't really measure your true maximum intelligence potential.

Thus, the fact that some groups have lower IQ than others wouldn't necessarily point to them being inherently / genetically disadvantaged.

As an aside, I don't know anything about the book or the authors' alleged motivations, but if they truly had no agenda, it's not very fair to be called racist because the result of your research says something politically incorrect, and you conveyed your true results to the best of your knowledge. This kind of torches-and-pitchforks behavior is just as bad for the advancement of knowledge as fudging up the numbers for ideological motivations.

An IQ score is literally your score on an IQ test; I think it’s more correct to talk about g (“general factor”) which is the principal component of intelligence you get if you measure a group of people on a battery of tests, and is the most predictive way to summarize an individual’s mental ability in a single number. A good IQ test is highly “g-loaded”, that is, it does a good job predicting someone’s scores on other tests that are g-loaded to some degree.

Intelligence, as with most traits, is influenced to some degree by genetics and to some degree by environments. This can be (approximately) measured by comparing differences in intelligence between people of varying degrees of relatedness (somewhere between being identical twins and being randomly selected people), who grew up either in the same families or separated. Usually people are interested in pairs of siblings or identical twins where one was raised by families of different socioeconomic statuses. When The Bell Curve was written, the authors said the consensus was that intelligence is between 40%–80% genetic, but I think it’s now thought to be on the high end of that. Intelligence is actually more influenced by genetics in adults than in children, which is the opposite of what you’d expect if environment actually did have a large effect.

When you say you can “study” for an IQ test, I think this is kind of tautological; e.g., you could memorize the answers to the hard problems, but intelligence is largely stable through life. It’s true that IQ scores have been rising for several decades (the Flynn effect), but I don’t think it’s ever been explained really well (maybe fewer people growing up in damaging environments?), it’s not clear whether or not people are actually getting smarter or they were just scoring better for some reason, and I think there’s evidence that the trend is starting to stall or maybe even decline since the mid 1990s.

Intelligence and socioeconomic status are certainly correlated, but I think it would actually be more correct to say “socioeconomic status is a proxy for intelligence” than the other way around. If intelligence is mostly genetic, with a small environmental factor, as it seems to be, and more intelligent people make more money on average, which they do, then socioeconomic status is certainly largely influenced by intelligence, and the heritability of intelligence at least partially explains why social mobility isn’t higher than it is. It’s probably the case that there’s some intelligence benefit from environmental factors resulting from socioeconomic status, but you can’t just try to throw out all the differences correlated with socioeconomic status, because there’s certainly some (likely more) influence in the other direction.

If measured average test score differences exist between genetic groups of people (they do), these differences again have to be some amount genetic in origin and some amount environmental. The amounts for between-group variation are probably similar to the amounts for within-group variation, but there are reasons why they might not be exactly the same. People often claim the tests are biased; what you can do to rule this out is to look at individual questions that certain groups of people get wrong more often, since it’s more likely that individual items are biased than that every question is biased by exactly the same amount. You can also look at things the tests predict, and see if they have the same predictive power across groups. For example, if someone claims the SAT is biased against racial minorities, you can look at college students in different racial groups and their SAT scores and see if the students in different groups with different average test scores do better or worse in college classes (I don’t know a good source off the top of my head, but to the best of my knowledge, the SAT is equally predictive across racial groups).

I strongly agree that the people claiming that psychometrics researchers have a racist agenda to prove white (or Asian?) superiority have a political agenda themselves, whereas the research in question seems to me pretty statistical, honest, and carried out without regard to the conclusions, and the researchers seem like they have to be very brave to carry out (or at least publicize) this research in the current political climate.

Some things in the papers made actually doubt them more. For example they mentioned one pair who they found wearing the same clothes and having given their kid the same name. I'm sorry, but there is no gene for tastes in clothes, at least not to that degree. Neither is there a gene for picking kids names. So those studies certainly overshot in some aspects.

In the actual IQ data there was also quite some variation.

Reading the summary at the top of the Wiki entry, it's already not surprising the book has been labeled racist. Any book that discusses race, inheritance, and socioeconomic class always gets called racist.

The Bell Curve is labeled racist because it is myopic about the existence and importance of race. Race is not a valid scientific categorization: it is not based on statistical grouping of DNA, or anything concrete other than "people used to be assholes to foreigners." There is an order of magnitude more genetic + cultural diversity among each race than there are between the races.

Examples, please, of books that investigate socioeconomic status & race that have not been called racist? Because I can't think of any. By the way, I'm not talking about literary explorations of race like "Huckleberry Finn". Although that was called racist too.

There are orders of magnitude more genetic [...] diversity among each race than there are between the races.

Hold it right there, buddy. License, registration, and sources please. Mostly sources.

Or you could read The Bell Curve. It is positing a small difference between "races", a difference so small that it is very minor compared to the expected range of deviation for a populace.

The idea that there is a scientifically definable thing called "race" lacks data. That is your row to hoe if you believe other. Skeptics are not required to disprove the existence of the tooth fairy, Nessie, or "race".

Or that asians and whites have wildly different reactions to milk.

Or that some diseases only affect blacks, or whites, or whatever?

This is not data? People use freely the same techniques to categorize humans, to categorize other animals with significant variations in their species, why only humans you must not use the word "race" and use other words to describe the same thing?

Asians and whites don't have wildly different reactions to milk. Adult mammals are generally lactose intolerant. There is a mutation that, in humans, is found far more often in people with ancestry in Northern Europe (which isn't coextensive with "whites") than any other origin, but which is neither universally absent in all other people or universally present in people of that origin that results in lactose tolerance.

Most supposed "racial" differences (EDIT: that is, most that refer to anything that is actually a measurable difference between real human populations at all) are of this type -- things that are statistically more or less common in a population of a particular origin that is not coextensive with any of the usual "race" categories with which the supposed hard-and-fast difference is popularly associated.

Thanks Wikipedia. Regarding being labelled racist, fine, everything gets labelled that. Even this post. I took your statement for something bit more meaningful than the cynic's "woe is the opinion of The Populous".

This is completely f'n stupid...

http://blogs.discovermagazine.com/gnxp/2010/12/to-classify-h...

[edit]

BTW, I find it funny that you're wiki-scholaring using old sources that date back to before we learned all non-african humans have some neanderthal dna in them.

Yawn...

http://en.wikipedia.org/wiki/Human_Genetic_Diversity:_Lewont...

http://en.wikipedia.org/wiki/Ashkenazi_Jewish_intelligence

My own guess is that for some blacks, there has not been enough time for the Flynn Effect to occur for them to catch up with the general population. This is not due to any fault in them, but a result of no/substandard education for many generations. I imagine in a few generations any difference from the average will disappear. http://en.wikipedia.org/wiki/Flynn_effect

Would have been curious to get an opinion by somebody who read it recently.