"Studies have shown that identical twins who grow up in separate families have an IQ correlation of 0.74, while adoptive siblings have no more similar IQ than strangers."
First off the bat, such studies are obviously social science, not science.
Secondly - there is this idea that one can boil entire brains down to one number like a CRC or checksum - the IQ number. Then you can rank them in order I suppose. It is obviously a ludicrous endeavor on reflection. It's like the Douglas Adams joke that the answer to life, the universe and everything is 42. When science actually makes progress on the brain, I'm sure biologists of the future will look on IQ like we look on phrenology.
Thirdly, these social science studies of twins mentioned were done by Thomas J. Bouchard, Jr. He's someone who writes op-eds for the Wall Street Journal - I guess Nature and Science are too full and his work crowded into there.
The second edition of the Mismeasure of Man by Stephen Jay Gould is a good book on this topic.
There was a hysterical conservative reaction to Gould's book just as there was a hysterical progressive reaction to the Bell Curve. Which shows this is really a political debate, not a scientific one. This is a political debate going back about 10,000 years, really. I am skeptical of any social scientific study that proposes it has found all the answers.
>Secondly - there is this idea that one can boil entire brains down to one number like a CRC or checksum - the IQ number. Then you can rank them in order I suppose. It is obviously a ludicrous endeavor on reflection.
Nothing of that diatribe is reflected in the statistic you just quoted. Pointing out a correlation between IQ doesn't necessarily mean IQ is some perfect heuristic to weed out the proles.
"'Studies have shown that identical twins who grow up in separate families have an IQ correlation of 0.74, while adoptive siblings have no more similar IQ than strangers.' ... First off the bat, such studies are obviously social science, not science."
This is an important and legitimate way to estimate broad-sense heritability. It won't control for environmental effects within the womb, or cultural effects, but it's pretty strong science absent those criticisms.
I know Thomas J. Bouchard, Jr., and he has been a participant in the journal club I mentioned in my top-level comment in this thread. He is a serious researcher on human behavior genetics and he has had publications in Science and other leading journals of peer-reviewed scientific research. I by no means claim that he would endorse all of my opinions about human behavior genetics, nor would I endorse all of his, but I will endorse him as a truth-seeker and straight shooter who attempts to take his opinions where the facts lead him, as he best understands the facts.
A lot of the rest of the tone of your reply is just setting up tribal affiliations and name-calling. But on the substance of what you wrote, perhaps you and I could agree in endorsing a review article by Eric Turkheimer (a colleague and occasional co-author of Bouchard's, and current president of the Behavior Genetics Association):
Turkheimer, E. (2012). Genome wide association studies of behavior are social science. In K. S. Plaisance & T.A.C. Reydon (Eds.) Philosophy of Behavioral Biology (pp. 43-64). New York, NY: Springer.
"If the history of empirical psychology has taught researchers anything, it is that correlations between causally distant variables cannot be counted on to lead to coherent etiological models."
The Mismeasure of Man is notoriously awful trash. It's amazing that anyone would recommend it as a reference or guide to the subject when its poor quality is so widely recognized by actual experts in the field.
Nobody believes that IQ expresses everything about our mental functioning. It is instead a useful and reliable way of measuring important aspects of cognitive ability.
First off the bat, such studies are obviously social science, not science.
Secondly - there is this idea that one can boil entire brains down to one number like a CRC or checksum - the IQ number. Then you can rank them in order I suppose. It is obviously a ludicrous endeavor on reflection. It's like the Douglas Adams joke that the answer to life, the universe and everything is 42. When science actually makes progress on the brain, I'm sure biologists of the future will look on IQ like we look on phrenology.
Thirdly, these social science studies of twins mentioned were done by Thomas J. Bouchard, Jr. He's someone who writes op-eds for the Wall Street Journal - I guess Nature and Science are too full and his work crowded into there.
The second edition of the Mismeasure of Man by Stephen Jay Gould is a good book on this topic.
There was a hysterical conservative reaction to Gould's book just as there was a hysterical progressive reaction to the Bell Curve. Which shows this is really a political debate, not a scientific one. This is a political debate going back about 10,000 years, really. I am skeptical of any social scientific study that proposes it has found all the answers.