More on IQ and Genetics
Here’s a rather nice piece to serve as a counterpoint to the John Derbyshire piece that was posted by Tom a few weeks ago.
A brief excerpt:
“Nearly all the evidence suggesting a genetic basis for the I.Q. differential is indirect. There is, for example, the evidence that brain size is correlated with intelligence, and that blacks have smaller brains than whites. But the brain size difference between men and women is substantially greater than that between blacks and whites, yet men and women score the same, on average, on I.Q. tests. Likewise, a group of people in a community in Ecuador have a genetic anomaly that produces extremely small head sizes — and hence brain sizes. Yet their intelligence is as high as that of their unaffected relatives.”
The Author, Richard E. Nisbett is no small potato, so take the article as something written by a well respected academic.
Comment by tet on 10 December 2007 at 9:14 am:
The brain size argument of the heredity folks has been discredited some time ago, I’m surprised he brought it up. There’s a guy in Britain with virtually no brain at all, just water and a lining inside the skull. His IQ tests around 87, I believe.
The “analogy bias” for testing has been discussed for years. One of the major aims for the past three decades has been the removal of this kind of bias. Last I heard, they had succeeded and differences still exist, despite what Nisbett wants to believe.
One possible explanation for the increase of IQ with increasing social status is the “regression to the mean” that occurs in populations. To wit: one reason for living in poverty in the first place, (all other things being equal) is low intelligence. Two people with IQs of 80 who marry will, most likely, have a child with an IQ of 90 or above. This increase would be visible, no doubt, to those testing.
All in all, I liked the article. I am somewhat interested in reading his book on the thought processes of Asians.
Tom
Comment by tet on 10 December 2007 at 1:54 pm:
Here’s an interesting take on the issue from Lisa Schiffren.
I can personally vouch for the serotonin-sensitive predilection towards being an addict being inherited, for example.
Tom
Comment by tet on 11 December 2007 at 8:44 am:
I’d like to read the original paper mentioned in this article.
They reviewers seem to be saying that not only are many of our traits genetic, but the rate of mutation is increasing rapidly.
Tom
Comment by Hanno on 11 December 2007 at 11:00 am:
Actually Tom the research suggests the exact opposite. Read your own article carefully. They say something along the lines of ‘this only measures past mutations, with current population movements and gene exchanges this has likely slowed or even almost stopped.’
Humans WERE diverging rapidly, but we’re smashing right back together.
Comment by Hanno on 11 December 2007 at 1:06 pm:
To be more precise
“The research identified evolutionary currents only in past times. In the modern era, greater movement and gene flow between the continents has probably slowed or even reversed patterns of increasing genetic difference, making the evolution of separate human species virtually impossible.”
Comment by tet on 11 December 2007 at 2:42 pm:
Ah, they are talking about speciation, Hanno. The sheer number of mutations are increasing.
What they’re saying is that even though the gross number of mutations is increasing, they’re being spread across the entire population due to intermarriage.
Whether or not that particular state continues for any length of time depends on how tribalism reacts to the next couple decades. If we split into enclaves, it should increase the rate of separation. If tribalism fails and individualism triumphs, there’ll be even more mutation (much of it purposeful and directed) but it’ll be wide-spread.
Hell, I can even see some eugenic-type species improvement by some group of fanatics or another–say using Mighty Mouse genes to make super-soldiers.
Tom
Comment by Hanno on 11 December 2007 at 10:37 pm:
How is it that “tribalism” and “individualism” are the only two options?
Now correct me if I’m wrong, but tribalism = ethnic enclaves, strong national identity, entnocentrism. Essentially Balkanization.
Individualism being withdrawal into the self unless you have a peculiar definition in these circumstances.
Now the two are hardly mutually exclusive. One can be tribalistic and rather individualistic. Of course there’s an entire spectrum of possibilities left out when you leave those as the only two options because they both suggest we’ll necessarily fragment rather than communalize or some other arrangement.