Friday, December 14, 2007
It was only eighteen months ago that I wrote a post titled "The implication of evolution after the dawn of agriculture." At the time, I was startled by the idea that there may have been evolutionary change within the human population in the last four centuries. Also at the time I was highly impressed by Evolutionary Psychology evolutionary functional analysis, and the concept of the Era of Evolutionary Adaption.
Since that time I have learned more about how biology informs the social sciences. It appears that evolution is faster than I thought, and Evolutionary Psychology is weaker than I assumed.
Up until recently, the theoretical maximum speed for one gene to replace all other variations was one every 300 generations. It now appears the rate among humans is 2 every year. If this result holds up, this has important implications.
Two dynamics appear to be driving the acceleration of natural selection among humans: larger population size (more mutations are given a chance to rise up) and the even quicker evolution of culture (preventing the establishment of an equilibrium optimal genetic state).
Evolutionary Psychology is wrong because there is no species-wide "Era of Evolutionary Adaption." Indeed, one wonders if the term "Era of Evolutionary Adaption" even makes sense. If it does, are EEAs of populations that had possessed agriculture for a very long time (say, the peoples of the fertile crescent, and Chinese and Indians of the great river valleys) far more agrarian than the EEAs of traditionally hunter-gatherer societies?
Further, as both cultural complexity and breeding population (both in numbers in and genetic diversity) vary historically, might one say that the Era of Evolutionary Adaption of Australian Aborigines is tens of thousands of years deeper in time than that of Indus River Valley dwellers?
Both the population of man and the culture of man have been growing at faster and faster rates. The implication of this is clear.
The 19th century saw more natural selection in our species than any other century, ever.
The 20th century saw more natural selection in our species than any other century, ever.
The 21st century will see more natural selection in oru species than any other century, ever.
And that's not counting genetic engineering.
(Thanks to Sean, DMH, Fulwider, Doug, and others for not letting me get past this discovery without thinking it through.)
Wednesday, December 12, 2007
Klingberg, T., Forssberg, H., & Westerberg, H. (2002). Training of working memory in children with ADHD. Journal of Clinical and Experimental Neuropsychology, 24(6), 781-791.
It's a good time for social scientists who like biology. From Shakespeare's wordplay to accelerating human evolution, biology is being used to explain more and more of our world. This is also true of topics that some people react to very emotionally, such as the role of genetic and environmental causes of human diversity in general intelligence.
The New Yorker has a mostly good article criticizing the role of genetics. Aside from a personal attack near the beginning, the article mostly emphasizes that changing environment changes general intelligence. It got me thinking if general intelligence itself could be changed by instruction, especially considering the finding that working memory correlates almost perfectly with IQ.
Well, Torkel Klinberg and colleagues asked that same question in 2002 and the answer is yes.
The researchers looked not only at measures of working memory, such as visuospatial working memory, and measures of general intelligence, such as Raven's progressive matrices, but also things you wouldn't expect: like head bobbing.
The measurement of head movements has been described in previous publications (Teicher et al., 1996). An infrared motion analysis system (OPTAx Systems, Burlington, MA) recorded the movements of a small reflective marker attached to the back of the head of the child. A movement was designed to begin when the marker moved 1.0mm or more from its most recent resting location. The number of movements was recorded during a 15-min period when the child was performing a version of a continuous performance task. In this task subjects were asked to respond to a target and withhold response to nontargets, with no requirement of holding any information in WM. Stimuli were presented every 2.0 s, and 50% of stimuli were target
Why include head-bobbing, you ask? Well, head-bobbing among ADHD students is already subject to medication -- so you can compare the benefits of training with the benefits of drugging:
The number of head movements was significantly reduced in the treatment group compared to the control group (Table 1, Fig. 1c). Again, this effect was evident in all subjects in the treatment group (Fig. 1c). The number of head movements during retest in the control group was about 6% higher than during the first testing. This is consistent with previous data on test-retest changes after administration of pharmacological placebo, where an increase of about 8% was found on the second testing (Teicher et al., 2000; Teicher, personal communication). The reduction of head movements in the treatment group was 74% (SEM 7). In comparison, a probe dose of methylphenidate (approximately 0.4 mg/kg) reduced the number of head movements by 62% (Teicher et al., 2000).
While the authors warn that more work is needed to see if this really leads to an increase in general intelligence, things look hopeful:
The present study showed that intensive and adaptive, computerized [working memory] WM training gradually increased the amount of information that the subjects could keep in WM (Tables 1 and 3, Figs. 1 and 2). The improved performance occurred over weeks of training, and is in this respect similar to the slow acquisition of a perceptual skill or a motor skill (Karni et al., 1995; Recanzone, Schreiner, & Merzenich, 1993; Tallal et al., 1996). Furthermore, the improvement from training was evident both for a group of children with ADHD (Experiment 1), as well as for adult subjects without ADHD (Experiment 2). This shows that an initial deficit inWMwas not necessary for improvement to occur.
All learners have two board sources of ability: knowledge of what they are doing, and the intelligence to apply it. Both of these can be improved with a positive environment, and both can be weakened by a bad environment.
To the extent that we wish to have a functioning systems administration at home and abroad, we must encourage those institutions that help develop skills and intelligence, and discourage those institutions that diminish them both.
Tuesday, December 04, 2007
Just because a side in an argument uses bad arguments doesn't mean it's wrong. By far, the least logic and most emotional rhetoric I have ever seen was in the newsgroup talk.origins in the late 1990s, where evolutionists were bufeddled and angered by the repleis of the creationists. That doesn't mean that descent with modification by natural selection is a wrong theory. It means that the truth was weaker in its rhetoric than the false.
With that said, Stephen Metcalf's "Dissecting the IQ Debate: A Response to William Saletan's Series on Race and IQ" (hat-tip to The Corner and South Dakota Politics) is awful.
After a lengthy ad hominem attack, Metcalf begins addressing evidence for racial differences in IQ.
Much of Saletan's précis of the rest of the research surveyed in "Thirty Years of Research Into Race Differences on Cognitive Abilities" is highly questionable. His takeaway regarding the "admixture" studies is precisely the opposite of what an American Psychological Association task force concluded the studies show—that more "European" blood in a black American does not make him smarter.
Pay attention here. Metcalf attacks Saletan for citing a peer-reviewed journal article, when a politically selected task force disagreed with its conclusions. No one denies the factual claims of the article: that European admixture positively correlates with general intelligence among African-Americans. Indeed, that alone is not evidence of innate racial differences. But the correlation between miscegenation and g in the population does not go away even when corrected for other variables.
Saletan points up the problems with a favorite study of the environmentalists, into the IQ outcomes of children fathered by foreign soldiers and raised by (white) German mothers. This study showed that kids with African fathers scored the same as those with white fathers. But, Saletan says, it suffers from a fatal flaw: Blacks in the military had been screened for IQ. Saletan concludes, "Even environmentalists (scholars who advocate nongenetic explanations) concede that this filter radically distorted the numbers." But this is flatly untrue. The two most prominent environmentalists, Richard Nisbett and James Flynn, have dismissed this very objection. Both have pointed out that white soldiers were also screened, and so had higher IQs than the general white population.
This regards a study that finds Germans with African-American fathers have an IQ about that of the German population. This might be explained by the fact that the military screens for IQ, rejecting a disproportionately high number of African-Americans for that reason. The counter-argument that European-Americans were also screened is besides the point: the US Army in WWII did not engage in affirmative action. The minimum IQ level for blacks was the same as the minimum IQ level for whites.
In the context of an attack on Howard Gardner's theory of multiple intelligences (10 page PDF), David F. Lohman (of the University of Iowa) presents this visualization of the hierarchies of intelligence tests:
The closer to the center, the more general lintelligence ("g") loads on the test. Some tests, such as identifying the correct endings of words, reading speed, or listening comprehension test "g" more indirectly than measures of verbal achievement, paper folding, or necessary arithemetic operations.
A good example is the Test Necessary Arithmetic Operations. This test was devised by Guilford to measure a specific cell in his Structure of the Intellect Model. Each item presents a short word problem. The examinee's task is not to solve the problem, but to say which two operations she would use, and in what order. There are four operations: add, subtract, multiply, and divide. Thus, problems do not require advanced mathematics. Yet in the sample of over 100 Stanford undergraduates who were administered most of the tests in Figure 2, Necessary Arithmetic Operations had one of the highest loadings on the [fluid intelligence] factor (Marshalek, Lohman, & Snow, 1983).
I meant this because of Mark's discussion of Dr. James Flynn on the Flynn Effect. Essentially, the Flynn effect explains the large-scale increase in measured general intelligence over the 20th century as reflecting increased society-wide patterns of practice on subtests. This implies two things: first, that tests should be renormalized every so often to make sure they still measure "g," and not practice. Second, that ability improves with practice.
It strikes me that, when properly normalized, IQ measures something psychobioneurological... perhaps not working memory exactly, but something not too far apart from that concept.
This has implications for the heritability of IQ. Most obviously, the more environment changes, the more change in performance can be traced to the environment. (Of course, as environments become more similar, more of the variation in the population will be explained by environments.)
Sunday, December 02, 2007
Those wacky creationists are at it again:
To Terry Erikheimer, the research itself is morally weighted. Given the complex nature of the fossil record, , Mr. Turkheimer said, “the question is fundamentally impossible to settle scientifically because we can never see people evolve from dinosaurs."
That doesn’t mean research into archeology should be banned, he said, but it should be judged. “What troubled me about posts at Cato” — an exchange Mr. Turkheimer participated in — “and the tone of Saletan’s blog is the assumption that because these papers are labeled as science, they are value-neutral and they’re as deserving of respect as any other scientific hypothesis,” he said of evolutionary theories.
“But you can’t get away from what these people are trying to prove, which is exactly the basis of the atheistic beliefs that informed segregation here for 200 years.”
Of course, the above section is a modified from the original New York Times article (hat-tip to Half Sigma). The research that is wrong, because of its implications, is on genetic differences between ancestral populations.
There are two large anti-science populations in the United States: Creationists and race-deniers. Creationists are far more numerous, but tend to be uneducated and without the power to do much. Occasionally some rally the support to force a school district to include a sticker in a bio book that evolution is only a theory -- which, of course, is true. (Gravity is another famous theory.)
Race-deniers are less numerous but far more powerful. Coming to power in academia with the rest of the Marxists in the 1960s and 1970s, race-deniers share the Creationists' fundamental fear of human biology. Further, they share with the creationists an essentially pagan intuition that if some people are found to be weaker than others, then they are less deserving of human rights. Creationists see evolutionists as social darwinists, eager to prove that the physically weak should starve. Race-deniers see evolutionists as segregationists, eager to prove that the genetically weak should drink at separate water fountains.
Instead of criticizing this paganism, the Creationists and race-deniers quietly accept it as a fact, and seek to modify facts so that they can keep their Christianist outcomes while holding on to pagan hearts.
Saturday, December 01, 2007
I'm currently "reading" (on abridged audio) World War Z: An Oral History of the Zombie War. WWZ is a "look back" at a saliva-spread contagion that takes over the mind of a biologically dead host, turning them into zombies that can only be killed through the destruction of the brain. The book starts with the identification of Patient 0 near the Three Gorges Dam. Currently, I'm at the Battle of Yonkers, where a a FutureCombatSystem equipped force battles an enemy (the zombies of New York) who are biologically incapable of being disoriented. An amazing read.
While the origin of the zombies is never fully explained, one hypothesis of the oral history is that it was a Chinese military experiment gone wrong. Freakily, scientists have developed a wasp that turns cockroaches into zombies (Slashdot, Nature). Nothing can possibly go wrong.
From the more social of the sciences, back in 2001 John Bargh and some others discussed "The Automated Will: Nonconscious activation and pursuit of behavioral goals" (14 page PDF) Across five experiments, the social scientists found evidence of sub-conscious will that "promote goal directed action [in] achievement [and] cooperation... increase in strength until acted on... promote persistence at task performance in the face of obstacles... and... favor resumption of disrupted tasks even in the presence of more attractive alternatives" (1024).
Meanwhile. Renee Friedman in Archeology weights evidence (tongue-in-cheek, we hope) of a Zombie attack in Hierkonopolis, subtitled "weighing the evidence for and dating of Solanum virus outbreaks in early Egypt." Perhaps the PLA is off the hook?
Watch out for zombies!
Thursday, November 29, 2007
Slashdot links to a Scientific American article titled "The Secret to Raising Smart Kids: Hint: Don't tell your kids that they are. More than three decades of research shows that a focus on effort—not on intelligence or ability—is key to success in school and in life." (Apparently, SciAm likes long titles.) There's a lot of work done in the margins on positive psychology, but two of the biggest factors are pretty simple:
- Make sure your mate is smarter than you
- Make sure your kid's friends are harder working than him
Of course, the main purpsoe of parenting isn't the creation of a high-achieving next generation. It's love. But high achievement doesn't necessarily hurt.
Friday, November 23, 2007
Half Sigma discovers "epigenetics," which is a general term for heritable elements that are not DNA. Maternal cytoplasm is an example of an epigenetic factor, though there probably are more. I assume that epigenetics probably works to exaggerate genetic differences. For instance, if two lands are otherwise equal, except one population is "genetically" higher in intelligence, that population is less likely to experience a famine, and so less likely to be epigenetically stunted.
At the same time, (courtesy of Crooked Timber) Eric Turkheimer of CATO speaks carefully about "innate" differences. Eric post essentially boils down to the fact that genes are expressed differently in different environments. Thus, it's possible to imagine a world, with the same DNA distribution, where sub-Saharan Africans outscore Jews on intelligence tests. And it's even easier to imagine a system where the general factor of intelligence does not correlate with verbal skill, spatial skill, height, etc. Of course, those worlds are not our worlds.
Adam of The Metropolis Times emphasizes that, whatever average group differences are, and whatever their origins, people should be judged as individuals. And human rights belong to all humans, not just who score well on tests.
Monday, November 19, 2007
Sunday, November 18, 2007
Courtsy of Half Sigma, an exceptionally good article from Slate.com on liberal creationism. The article is solid and unremarkable, other than for its intended audience. What's most interesting are the comments it generated from Salonists. I lurked in the forum, and found some zingers.
My favorite is so over-the-top I wonder if i is a satire:
I don't care what the "scientific evidence" says - I'll never believe the "truth" that the races aren't equal. We've fought too hard for too long. I also am very disappointed to see Slate publish this pablum - maybe in the National Review or whatever rag Herr Bush reads, but not Slate.
Another clearly disaproves of gnxp:
Jason Malloy is a member of one of the most notorious racist blogs on the Internet -- Gene Expression. The bloggers there claim blacks and Hispanics are geneticially inferior -- a missing link between apes and humans. Ironically, Malloy himself is at least a quarter black, but can pass for white. Hatred of his own ancestry seems to motivate him. He has no background whatsoever in science.
Steveangr takes a pot-shot at christian Creationism while defending his own kind:
Christians go through a phase because they were indoctrinated to sth that is false and now they have either to come in terms with the false bearing or choose the right thing which is different from their upbringing. Believing that there is no inherent genetic trait to intelligence, is not only supported by science -thus far- but it is wrong to thing otherwise, it's yours the pit you have dug there...
The comments I linked to were about average. Some were well meaning but misinformed. Others were emotional and clearly hurt. A few trotted out things they clearly learned in a 100-level class, and authoratively stated that anyone who took a freshman-level class would realize.
All in all, a good read if you're looking for dogmatism.