A post from Gregory Cochran's and Henry Harpending's excellent blog West Hunter.

One of the many interesting aspects of how the US dealt with the AIDS epidemic is what we didn’t do – in particular, quarantine.  Probably you need a decent test before quarantine is practical, but we had ELISA by 1985 and a better Western Blot test by 1987.

There was popular support for a quarantine.

But the public health experts generally opined that such a quarantine would not work.

Of course, they were wrong.  Cuba institute a rigorous quarantine.  They mandated antiviral treatment for pregnant women and mandated C-sections for those that were HIV-positive.  People positive for any venereal disease were tested for HIV as well.  HIV-infected people must provide the names of all sexual partners for the past sic months.

Compulsory quarantining was relaxed in 1994, but all those testing positive have to go to a sanatorium for 8 weeks of thorough education on the disease.  People who leave after 8 weeks and engage in unsafe sex undergo permanent quarantine.

Cuba did pretty well:  the per-capita death toll was 35 times lower than in the US.

Cuba had some advantages:  the epidemic hit them at least five years later than it did the US (first observed Cuban case in 1986, first noticed cases in the US in 1981).  That meant they were readier when they encountered the virus.  You’d think that because of the epidemic’s late start in Cuba, there would have been a shorter interval without the effective protease inhibitors (which arrived in 1995 in the US) – but they don’t seem to have arrived in Cuba until 2001, so the interval was about the same.

If we had adopted the same strategy as Cuba, it would not have been as effective, largely because of that time lag.  However, it surely would have prevented at least half of the ~600,000 AIDS deaths in the US.  Probably well over half.

I still see people stating that of course quarantine would not have worked: fairly often from dimwitted people with a Masters in Public Health.

My favorite comment was from a libertarian friend who said that although quarantine  certainly would have worked, better to sacrifice a few hundred thousand than validate the idea that the Feds can sometimes tell you what to do with good effect.

The commenter Ron Pavellas adds:

I was working as the CEO of a large hospital in California during the 1980s (I have MPH as my degree, by the way). I was outraged when the Public Health officials decided to not treat the HI-Virus as an STD for the purposes of case-finding, as is routinely and effectively done with syphilis, gonorrhea, etc. In other words, they decided to NOT perform classic epidemiology, thus sullying the whole field of Public Health. It was not politically correct to potentially ‘out’ individuals engaging in the kind of behavior which spreads the disease. No one has recently been concerned with the potential ‘outing’ of those who contract other STDs, due in large part to the confidential methods used and maintained over many decades. (Remember the Wassermann Test that was required before you got married?) As is pointed out in this article, lives were needlessly lost and untold suffering needlessly ensued.

The Wasserman Test.

Related: Son of Low Hanging Fruit

Another post on finding low hanging fruit from Gregory Cochran's and Henry Harpending's blog West Hunter.

Clostridium difficile causes a potentially serious kind of diarrhea triggered by antibiotic treatments. When the normal bacterial flora of the colon are hammered by a broad-spectrum antibiotic, C. difficile often takes over and causes real trouble.  Mild cases are treated by discontinuing antibiotic therapy, which often works: if not, the doctors try oral metronidazole (Flagyl), then vancomycin , then intravenous metronidazole.  This doesn’t always work, and C. difficile infections kill about 14,000 people a year in the US.

One recent trial shows that fecal bacteriotherapy, more commonly called a stool transplant, works like gangbusters, curing ~94% of patients. The trial was halted because the treatment worked so well that refusing to poopify the control group was clearly unethical.  I read about this, but thought I’d heard about such stool transplants some time ago.  I had.  It was mentioned in The Making of a Surgeon, by William Nolen, published in 1970. Some crazy intern – let us call him Hogan – tried a stool transplant on a woman with a C. difficile infection. He mixed some normal stool with chocolate milk and fed it to the lady.  It made his boss so mad that he was dropped from the program at the end of the year.  It also worked. It was inspired by a article in Annals of Surgery, so this certainly wasn’t the first try.  According to Wiki,  there are more than 150 published reports on stool transplant, going back to 1958.

So what took so damn long?  Here we have a simple, cheap, highly effective treatment for C. difficile infection that has only become officially valid this year. Judging from the H. pylori  story, it may still take years before it is in general use.

Obviously, sheer disgust made it hard for doctors to embrace this treatment.  There’s a lesson here: in the search for low-hanging fruit,  reconsider approaches that are embarrassing, or offensive, or downright disgusting.

Investigate methods were abandoned because people hated them, rather because of solid evidence showing that they didn’t work.

Along those lines, no modern educational reformer utters a single syllable about corporal punishment: doesn’t that make you suspect it’s effective?  I mean, why we aren’t we caning kids anymore?  The Egyptians said that a boy’s ears are in his back: if you do not beat him he will not listen. Maybe they knew a thing or three.

Sometimes, we hate the idea’s authors: the more we hate them, the more likely we are to miss out on their correct insights. Even famous assholes had to be competent in some areas, or they wouldn’t have been able to cause serious trouble.

Related: Loss of local knowledge affecting intellectual trends, The Hyborian Age

This post is from Gregory Cochran's and Henry Harpending's excellent blog West Hunter.

Barry Marshall once said that if he had gone to Harvard, he would have known that stomach ulcers were caused by stress, and wouldn’t even have considered the possibility that they might be caused by a bacterium.  There are a number of other important innovators that sure look as if they benefited from living as far as possible from  the sources of establishment opinion.  Back when continental drift was officially nonsense,  quite a few geologists in South Africa and Australia thought it must be correct – partly because there are local geological facts that are hard to explain any other way (like ancient glacial moraines in Australia whose rocks originated in South Africa) but also because physical distance translates into mental distance.

Of course this does not always work – distance is useful, but not sufficient..  Indonesia is pretty far from Harvard, but is a vast wasteland, intellectually.  Ideally, you want a country full of people drawn from the  populations that actually produce creative thinkers (Europeans, mostly) instead of the populations that ought to but don’t.  And it should be really, really far away.

With the Internet and cell phones and all that,  psychological isolation is harder to find. Once even California had some thoughts of its own, but that day is long past. If we want to keep progress from stalling out, we need people that don’t get sucked into to the usual crap – because they can’t.

The only real solution is interstellar colonization: the speed of light is your friend.  A generation ship might do the job -  even if it never arrived. It would be out there for hundreds of years, years in which the inhabitants could go their own way.  Some of the ships would be boring, some of them would go crazy – but at least they’d be different.

Related: Thick and Thin, Loss of local knowledge affecting intellectual trends

An entry I found in the archives on Gregory Cochran's and Henry Harpending's blog West Hunter.

In yet another example of  long-delayed discovery, forms of high-altitude lightning were observed for at least a century before becoming officially real (as opposed to really real).

Some thunderstorms manage to generate blue jets shooting out of their thunderheads, or  glowing red rings and associated tentacles around 70 kilometers up.   C T R Wilson predicted this long ago, back in the 1920s.  He had a simple model that gets you started.

You see, you can think of the thunderstorm, after a ground discharge,  as a vertical dipole. Its electrical field drops as the cube of altitude.  The threshold voltage for atmospheric breakdown is proportional to pressure, while pressure drops exponentially with altitude: and as everyone knows, a negative exponential drops faster than any power.

The curves must cross.   Electrical breakdown occurs.  Weird lightning, way above the clouds.

As I said, people reported sprites at least a hundred years ago, and they have probably been observed occasionally since the dawn of time. However, they’re far easier to see if you’re above the clouds – pilots often do.

Pilots also learned not to talk about it, because nobody listened.   Military and commercial pilots have to pass periodic medical exams known as ‘flight physicals’,  and there was a suspicion that reporting glowing red cephalopods in the sky might interfere with that.  Generally, you had to see the things that were officially real (whether they were really real or not), and only those things.

Sprites became real when someone recorded one by accident on a fast camera in 1989.  Since then it’s turned into a real subject, full of strangeness: turns out that thunderstorms  sometimes generate gamma-rays and even antimatter.

Presumably we’ve gotten over all that ignoring your lying eyes stuff by now.

May you tell others what you see. (~_^)

Your daily dose of science knowledge will once more be provided by Gregory Cochran, clearing up some misconceptions you may have heard about Epigenetics.

As I understand it, in some circles,  there is a burgeoning hope that practice in this generation will somehow improve performance in the next – based on a word they have heard but do not understand. That word is epigenetics.

Genes can certainly be modified in ways that persist.   For example, the cells in your skin produce more skin cells when they divide, rather than muscle cells or neurons.  Most of your cells have a copy of the entire human genome, but only certain elements are expressed in a particular type of cell, and that pattern persists  when that  kind of cell divides. We understand, to a degree, some of the chemical changes that cause these lasting changes in gene expression patterns.   One is methylation,  a method of suppressing gene activity.  It involves attaching a methyl group to a cytosine base. This methylation pattern is copied when somatic cells divide.

The question is whether A. such changes can persist into the next generation and B. if they do, is this some sort of adaptive process, rather than an occasional screwup?  We’re  interested in whether this happens in humans,  so we’ll only consider mammals.

It’s rare, but sometimes it happens.  It has only been found to happen at a few sites in the genome, and when it does happen,  only a fraction of the offspring are affected. Probably the best known example is the agouti yellow allele in mice.  Mice that carry this allele are fat, yellow, and prone to cancer and diabetes – some of them. Yellow mothers tend to have yellow babies,  while genetically identical brown mothers mostly have brown babies.  The agouti yellow allele is the product of a recent insertion in the genome, about 50 years ago.  For the overwhelming majority of genes, the epigenetic markers are reset in a new embryo, which means that epigenetic changes induced by the parent’s experiences disappear.  The embryo is back at square one.   This agouti yellow allele is screwed up – somehow the reset isn’t happening correctly.

In mice, the mammalian species in which most such investigations have been done,  the few other locations in the genome where anything like this happens are mainly retroposons and other repeated elements.

There is another way that you can get transmission across generations without genetic change.  Rats that are nurtured by stressed mothers are more likely to be stressed.  This isn’t transmitted perfectly, but it happens.  Presumably the uterine environment,  or maybe maternal behavior, is different in stressed mice in a way that stresses their offspring.   This reminds me of a science fiction story that abused this principle.  The  idea was that alligators (or maybe it was crocodiles) almost have a four-chambered heart, which is generally associated with higher metabolism and friskiness. Our protagonist operates on an alligator and soups up its heart: the now-more-vigorous animal has better blood circulation and lays healthier eggs that develop into babies that also have a working four-chambered heart. So ‘normal’ alligators were like stressed mice: fix the problem and you get to see what they’re really capable of. The problem was that the most interesting consequence was growing wings, flying around and eating people. Alligators turned out to be stunted dragons. Not so good.

Anyhow, what reason is there to believe that reading Gradshteyn and Ryzhik until your eyes bleed will plant the seeds of math to come in your descendants?  None. Oh, I can come up with a scenario, if you want: but it requires that civilization (in particular, the key part of civilization, heavy use of weird definite and indefinite integrals and vast reproductive rewards for those skilled in such things) has risen and fallen over and over again at fairly short (but irregular)  intervals, so that humans have faced this adaptive problem over and over and over again.  A little like the way in which generations of aphids do different things in the summer (parthenogenesis) than in the late fall (sexual reproduction) – although that probably depends on direct cues like length of day rather than epigenetic changes.  Something like Motie history, maybe. But  I don’t believe it.  Not even a little bit.

Nature hasn’t even figured out how to have Jewish boys be born circumcised yet.

So why are people talking about this? Why do people like Tyler Cowen invoke it to ward off evil facts?

Because they’re chuckleheads, what else?

I think we can be a bit more specific that that so lets take it as an exercise. Motivated cognition for starters.

If you want to learn why the Conan the Barbarian was generated by better priors than modern history books, what the blind idiot god may have in store for you or how to solve thick problems check out other articles from the blog shared under the tag: westhunter 

A new interesting entry on Gregory Cochran's and Henry Harpending's well known blog (West Hunter). For me the information I gained from the LessWrong articles on inferential distances complemented it nicely. Link to source.

There is a spectrum of problem-solving, ranging from, at one extreme, simplicity  and clear chains of logical reasoning (sometimes long chains) and, at the other,  building a picture by sifting through a vast mass of evidence of  varying quality.  I will give some examples. Just the other day, when I was conferring, conversing and otherwise hobnobbing with my fellow physicists, I mentioned high-altitude lighting, sprites and elves and blue jets.   I said that you could think of a thundercloud as a vertical dipole,  with an electric field that decreased as the cube of altitude, while the breakdown voltage varied with air pressure, which declines exponentially with altitude. At which point the prof I was talking to said ” and so the curves must cross!”.  That’s how physicists think, and it can be very effective. The amount of information required to solve the problem is not very large. I call this a ‘thin’ problem’.

At the other extreme,  consider Darwin gathering and pondering on a vast amount of natural-history information, eventually coming up with natural selection as the explanation.   Some of the information in the literature  wasn’t correct, and much  key information that would have greatly aided his  quest, such as basic genetics, was still unknown.   That didn’t stop him, anymore than not knowing the cause of continental drift stopped Wegener.

In another example at the messy end of the spectrum, Joe Rochefort, running Hypo in the spring of 1942,  needed to figure out Japanese plans. He had an an ever-growing mass of Japanese radio intercepts, some of which were partially decrypted – say, one word of five, with luck.   He had data from radio direction-finding; his people were beginning to be able to recognize particular Japanese radio operators by their ‘fist’.  He’d studied in Japan, knew the Japanese well.  He had plenty of Navy experience – knew what was possible. I would call this a classic ‘thick’ problem, one in which an analyst needs to deal with an enormous amount of data of varying quality.  Being smart is necessary but not sufficient: you also need to know lots of  stuff.

At this point he was utterly saturated with information about the Japanese Navy.  He’d been  living and breathing JN-25 for months. The Japanese were aimed somewhere,  that somewhere designated by an untranslated codegroup – ‘AF’.  Rochefort thought it meant Midway, based on many clues, plausibility, etc.  OP-20-G, back in Washington,  thought otherwise. They thought the main attack might be against Alaska, or Port Moresby, or even the West Coast.

Nimitz believed Rochefort – who was correct.  Because of that, we managed to prevail at Midway, losing one carrier and one destroyer while the the Japanese lost four carriers and a heavy cruiser*.  As so often happens, OP-20-G won the bureaucratic war:  Rochefort embarrassed them by proving them wrong, and they kicked him out of Hawaii, assigning him to a floating drydock.

The usual explanation of Joe Rochefort’s fall argues that John Redman’s ( head of OP-20-G, the Navy’s main signals intelligence and cryptanalysis group) geographical proximity to Navy headquarters  was a key factor in winning the bureaucratic struggle, along with his brother’s influence (Rear Admiral Joseph Redman).  That and being a shameless liar.

Personally, I wonder if part of the problem is the great difficulty of explaining the analysis of a thick problem to someone without a similar depth of knowledge.  At best, they believe you because you’ve  been right in the past.  Or, sometimes, once you have developed the answer, there is a ‘thin’ way of confirming your answer – as when Rochefort took Jasper Holmes’s suggestion and had Midway broadcast an uncoded complaint about the failure of their distillation system – soon followed by a Japanese report that ‘AF’ was short of water.

Most problems in the social sciences are ‘thick’, and unfortunately, almost all of the researchers are as well. There are a lot more Redmans than Rocheforts.

Those of us who have found the arguments for stagnation in our near future by Peter Thiel and Tyler Cowen pretty convincing, usually look only to the information and computer industries as something that is and perhaps even can keep us afloat. On the excellent West Hunters blog (which he shares with Henry Harpending) Gregory Cochran speculates that there might be room for progress in a seemingly unlikely field.

Low-hanging fruit

In The Great Stagnation, Tyler Cowen discusses a real problem – a slowdown in technical innovation,  with slow economic growth as a consequence..   I think his perspective is limited, since he doesn’t know much about the inward nature of innovation. He is kind enough to make absolutely clear how little he knows by mentioning Tang and Teflon as spinoffs of the space program, which is  of course wrong. It is unfair to emphasize this too strongly, since hardly anybody in public life knows jack shit about technology and invention. Try to think of a pundit with a patent.

Anyhow, it strikes me that a certain amount of knowledge  may lead to useful insights. In particular, it may help us find low-hanging-fruit, technical innovations that are tasty and relatively easy – the sort of thing that seems obvious after someone thinks of it.

If we look at cases where an innovation or discovery was possible – even easy – for a long time before it was actually developed, we might be able to find patterns that would help us detect the low-hanging fruit  dangling right in front of us today.

For now, one example.  We know that gastric and duodenal ulcer, and most cases of stomach cancer, are caused by an infectious organism, helicobacter pylori.  It apparently causes amnesia as well. This organism was first seen in 1875 – nobody paid any attention.

Letulle showed that it induced gastritis in guinea pigs, 1888. Walery Jaworski rediscovered it in 1889, and suspected that it might cause gastric disease. Nobody paid any attention.  Krienitz associated it with gastric cancer in 1906.  Who cares?

Around 1940, some American researchers rediscovered it, found it more common in ulcerated stomachs,  and published their results.  Some of them thought that this might be the cause of ulcers – but Palmer, a famous pathologist,  couldn’t find it when he looked in the early 50s, so it officially disappeared again. He had used the wrong stain.  John Lykoudis, a Greek country doctor noticed that a heavy dose of antibiotics coincided with his ulcer’s disappearance, and started treating patients with antibiotics – successfully.   He tried to interest pharmaceutical companies – wrote to Geigy, Hoechst, Bayer, etc.  No joy.   JAMA rejected his article. The local medical society referred him for disciplinary action and fined him

The Chinese noticed that antibiotics could cure ulcers in the early 70s, but they were Commies, so it didn’t count.

Think about it: peptic and duodenal ulcer were fairly common, and so were effective antibiotics, starting in the mid-40s. . Every internist in the world – every surgeon – every GP was accidentally curing ulcers  – not just one or twice,  but again and again.  For decades. Almost none of them noticed it, even though it was happening over and over, right in front of their eyes.  Those who did notice were ignored until the mid-80s, when Robin Warren and Barry Marshall finally made the discovery stick. Even then,  it took something like 10 years for antibiotic treatment of ulcers to become common, even though it was cheap and effective. Or perhaps because it was cheap and effective.

This illustrates an important point: doctors are lousy scientists, lousy researchers.  They’re memorizers, not puzzle solvers.  Considering that Western medicine was an ineffective pseudoscience – actually, closer to a malignant pseudoscience  – for its first two thousand years, we shouldn’t be surprised.    Since we’re looking for low-hanging fruit,  this is good news.  It means that the great discoveries in medicine are probably not mined out. From our point of view, past incompetence predicts future progress.  The worse, the better!

Link to post.

I think Greg is underestimating the slight problems of massive over-regulation and guild-like rent seeking that limits medical research and providing medical advice quite severely. He does however make a compelling case for there to still be low hanging fruit there which with a more scientific and rational approach could easily be plucked. I also can't help but wonder if investigating older, supposedly disproved, treatments and theories together with novel research might bring up a few interesting things.

Many on LessWrong share Greg's estimation of the incompetence of the medical establishment, but how many share his optimism that our lack of recent progress isn't just the result of dealing with a really difficult problem set? It may be hard to tell if he is right.

Yay a new cool post is up on West Hunters blog! It is written by Gregory Cochran and Henry Harpending with whom most LWers are probably already familiar with (particularly this awesome entry). It raises some interesting points on biases in academia.

I was contemplating Conan the Barbarian, and remembered the essay that Robert E. Howard wrote about the  background of those stories – The Hyborian Age.  I think that the flavor of Howard’s pseudo-history is a lot more realistic than the picture of the human past academics preferred over the past few decades.

In Conan’s world, it’s never surprising to find a people that once mixed with some ancient prehuman race.  Happens all the time.  Until very recently, the vast majority of workers in human genetics and paleontology were sure that this never occurred – and only changed their minds when presented with evidence that was both strong (ancient DNA)  and too mathematically sophisticated for them to understand or challenge (D-statistics).

Conan’s history  was shaped by the occasional catastrophe.  Most academics (particularly geologists) don’t like catastrophes, but they have grudgingly come to admit their importance – things like the Thera and Toba eruptions, or the K/T asteroid strike and the Permo-Triassic crisis.

Between the time when the oceans drank Atlantis, and the rise of the sons of Aryas, evolution seems to have run pretty briskly, but without any pronounced direction.  Men devolved into ape-men when the environment pushed in that direction (Flores ?)  and shifted right back when the environment favored speech and tools.  Culture shaped evolution, and evolution shaped culture.  An endogamous caste of snake-worshiping priests evolved in a strange direction.  Although their IQs were considerably higher than average, they remained surprisingly vulnerable to sword-bearing barbarians.

In this world, evolution could happen on a time scale of thousands of years, and there was no magic rule that ensured that the outcome would be the same in every group.  It may not be PC to say it, but Cimmerians were smarter than Picts.

The basic idea of their book "The 10 000 Year Explosion" (LessWrong review, Amazon).

Above all, people in Conan’s world fought. They migrated: they invaded.  There was war before, during, and after civilization.  Völkerwanderungs were a dime a dozen. Conquerors spread.  Sometimes they mixed with the locals, sometimes they replaced them – as when the once dominant Hyborians, overrun by Picts, vanished from the earth, leaving scarcely a trace of their blood in the veins of their conquerors. They must have been U5b.

To be fair,  real physical anthropologists in Howard’s day thought that there had been significant population movements and replacements in Europe, judging from changes in skeletons and skulls that accompanied archeological shifts, as when people turned taller, heavier boned , and brachycephalic just as the Bell-Beaker artifacts show up. But those physical anthropologists lost out to people like Boas – liars.

Perhaps this little old entry is relevant here. ^_^

Given the chance (sufficient lack of information), American anthropologists assumed that the Mayans were peaceful astronomers. Howard would have assumed that they were just another blood-drenched snake cult: who came closer?

Now I’m not saying that Howard got every single tiny little syllable of prehistory right.  Not likely: so far, we haven’t seen any signs of Cthulhu-like visitors, which abound in the Conan stories.  So far. But Howard’s priors were more accurate than those of the pots-not-people archeologists: more accurate than people like Excoffier and  Currat, who assume that there hasn’t been any population replacement in Europe since moderns displaced Neanderthals. More accurate than Chris Stringer,  more accurate than Brian Ferguson.

Most important, Conan, unlike the typical professor, knew what was best in life.

Heh.

Cochran you are such a nerd.

So we say we know evolution is an alien god, which can do absolutely horrifying things to creatures. And surely we are aware that includes us, but how exactly does one internalize something like that? Something so at odds with default cultural intuitions. It may be just my mood tonight, but this short entry on the West Hunter (thanks Glados) blog really grabbed my attention and in a few short paragraphs on a hypothesis regarding the Hobbits of Flores utterly changed how I grok Eliezer's old post.

There is still doubt, but there seems to be a good chance that the Flores Hobbit was a member of a distinct hominid species, rather than some homo sap with a nasty case of microcephalic dwarfism.   If this is the case, the Hobbits are likely descended from a small, Australopithecus-like population that managed to move from Africa to Indonesia without leaving any fossils in between, or from some ancient hominid (perhaps homo erectus) that managed to strand themselves on Flores and then shrank, as many large animals do when isolated on islands.

Island dwarfing of a homo erectus population is the dominant idea right now.  However, many proponents are really bothered by how small the Hobbit’s brain was.  At 400 cc, it was downright teeny, about the size of a chimpanzee’s brain.  Most researchers seem to think that hominid brains naturally increase in size with time. They also suspect that anyone with a brain this small couldn’t be called sentient – and the idea of natural selection driving a population from sentience to nonsentience bothers them.

They should get over it.  Hominid brain volume has increased pretty rapidly over the past few million years, but the increase hasn’t been monotonic.  It’s decreased about 10% over the past 25,000 years. Moreover, we know of examples where natural selection has caused drastic decreases in organismal complexity – for example, canine venereal sarcoma, which today is an infectious cancer, but was once a dog.

I have to break here to note that was the most awesome fact I have learned in some time.

There is a mechanism that might explain what happened on Flores – partial mutational meltdown.  Classic mutational meltdown occurs when a population is too small for too long. Selection is inefficient in such a small population: alleles that decrease fitness by less than 1/N drift fairly freely, and can go to fixation.  At the same time, favorable mutations, which are very rare, almost never occur.  In such a situation, mutational load accumulates – likely further reducing population size – and the population spirals down into extinction. Since small population size and high genetic load increase vulnerability to disaster, some kind of environmental catastrophe usually nails such doomed, shrinking populations before they manage to die off from purely genetic causes.

In principle, if the  population is the right size and one adaptive function is considerably more complicated than others, presenting a bigger mutational target,  you might see a population suffer a drastic decline in that function while continuing to exist. There is reason to think that intelligence is the most complex adaptation in hominids. More than half of all genes are expressed in the brain, and it seems that a given degree of inbreeding depression – say cousin marriage – depressesIQ more than other traits.

Flores is not that big an island and the population density of homo-erectus type hunter-gatherers must have been low – certainly lower than that of contemporary hunter-gatherers, who have much more sophisticated tools.  Thus the hobbit population was likely small.  It may not have been possible to sustain a high-performing brain over the long haul in that situation.  Given that their brains performed poorly – while the metabolic costs were as high as ever – selection would have shrunk their brains.  Over hundreds of thousands of years, this could well have generated the chimp-sized brain we see in the LB1 skeleton.

Of course, this could only have happened if there was an available ecological niche that did not require human-level intelligence.  And there was such an opening: Flores had no monkeys.

That last sentence just struck me with utter horror.

A recent entry from the West Hunters blog (written by Gregory Cochran and Henry Harpending with whom most LWers are probably already familiar with) caught my eye: 

People who grow up in a small town, or an old and stable neighborhood, often know their neighbors.  More than than that, they know pretty much everything that’s happened for the past couple of generations, whether they want to or not.  For many Americans, probably most,  this isn’t the case. Mobility breeds anonymity.  Suburban kids haven’t necessarily been hanging out with the same peers since kindergarten, and even if they have, they probably don’t much about their friends’ sibs and parents.

If you do have that thick local knowledge, significant trait heritability is fairly obvious.  You notice that the valedictorians cluster in a few families, and you also know that those families don’t need to put their kids under high pressure to get those results. They’re just smart. Some are smart but too rebellious to play the game – and that runs in families too. For that matter, you know that those family similarities, although real and noticeable, are far from absolute.  You see a lot of variation within a family.

If you don’t have it, it’s easier to believe that cognitive or personality traits are generated by environmental influences – how your family toilet trained you, whether they sent you to a prep school, etc.  Easier to believe, but false.

So it isn’t all that difficult to teach quantitative genetics to someone with that background. They already know it, more or less.  Possession of this kind of knowledge must have been the norm in the human past. I’m sure that Bushmen have it.

The loss of this knowledge must have significant consequences, not just susceptibility to nurturist dogma.  In the typical ancestral situation, you knew a lot about the relatives of all potential mates.  Today, you might meet someone in college and know nothing about her family history.  In particular, you  might not be aware that schizophrenia runs in her family. You can’t weigh what you don’t know.  In modern circumstances, I suspect that the reproductive success of people with a fair-sized dose of alleles that predispose to schiz has gone up – with the net consequence that selection is less effective at eliminating such alleles. The modern welfare state has probably had more impact, though.  In the days of old, kids were likely to die if a parent flaked out.  Today that does not happen.

Seems quite coherent. It meshes well with findings that the more children parents have the less they subscribe to nurture, since they finally, possibly for the first time ever, get some hands on experience with the nurture (nurture as in stuff like upbringing not nurture as in lead paint) versus. nature issue. Note that today urban, educated, highly intelligent people are less likley to have children than possibly ever, how is this likley to effect intellectual fashions?

Perhaps somewhat related to this is also the transition in the past 150 years (the time frame depending on where exactly you live) from agricultural communities, that often raised livestock to urban living. What exactly "variation" and "heredity" might mean in a intuitive way thus comes another source short with no clear replacement.