Note: If you look around this blog, you will notice it takes pride in freedom of expression. It does not shy away from controveries, e.g. IQ and genetics. This article is a perfect example of both, but if you will also read another article by Hank Pellissier, – Disease, Violence, Malnutrition, Pollution, Illiteracy, Five Scourges that Cripple IQ in Sub-Saharan Africa , – you will see how we take pride also in counter-balancing views. In fact we take high standards of academic integrity very seriously !
Gregory Cochran’s ideas are highly controversial. Although he’s a physicist, he’s written extensively, and edgily, on anthropology and genetics, with theories that have earned him a scandalous reputation. He’s suggested that homosexuality is caused by a virus, and he frequently links racial background and IQ. He’s also co-author of The 10,000 Year Explosion, which postulates that human evolution has accelerated during that time. Cochran has received bad press and scant funding for his research, although he’s secretly admired by others who are too afraid to speak out. I interviewed the inflammatory scientist by email recently:
Hank Pellissier: I wrote an article last year titled, “Why is the IQ of Ashkenazi Jews so High?” Can you give me your own answer to that question?
Gregory Cochran: Selection. Genetics. Nothing in their cultural environment today. Those factors have little influence on IQ. The correlation between adopted kids and their adoptive parents [in IQ studies] is close to zero by adulthood.
HP: I am curious if you have come across any further evidence of neurogenesis and the Ashkenazi genetic diseases. In your opinion, could using the heterozygote potential of these diseases in genetic engineering lead to superior general intelligence? Could pre-implantation of the Gaucher’s allele, for example, give the general population an IQ boost of 10-15 points?
GC: I would guess that any IQ boost due to Gaucher’s is a good deal less than 10-15 points. It may be that big for torsion dystonia: everyone who has treated them marvels at how sharp they are. Of course, with that mutation, you take a 10% risk of being a human pretzel. Do you feel lucky? Parenthetically, we think that most of the IQ boost among the Ashkenazi is from selection acting on many, many locis that each have a small influence on intelligence, which is commonly the case in selection experiments. Only a fraction is due to particular mutations like Gaucher, in our opinion.
HP: I also wrote an essay on environmental IQ factors affecting Sub-Saharan Africans. I am a “liberal” guy but I get called horrible names like neo-Nazi when I write on topics that appear to simultaneously discuss IQ and ethnicity.
GC: “No one has ever had a fantasy about being tied to a bed and sexually ravished by someone dressed as a liberal.” A good line by P. J. O’Rourke, even though he is a jerk.
Your essay was too optimistic. Genes play a larger role than you think. Most environmental factors don’t have much effect on intelligence – although a few do, like iodine deficiency. Scores are just as low in South Africa as in the rest of sub-Saharan Africa, even though it is an industrial society with good public health (except for HIV) – chlorinated water and all that. Scores are low everywhere in the African diaspora.
In the US and other western countries, we know that most of the variance in IQ is due to genetic factors. We also know that the non-genetic factors that do exist are not the ones that people assume ought to – not the way you’re raised, number of books in the house, etc. In fact we know what they aren’t (not genetics, not between-family environmental variables) rather than exactly what they are.
The study by Randy Thornhill and company about pathogen load: it can’t be right in the US. Maybe to some degree in Africa, which is one sickly continent. The amount of malaria in Florida and North Dakota today is exactly the same: zero. Disease load used to be higher in the South than the North, but not for two generations now. On the other hand, there is a strong worldwide correlation between latitude and IQ: nobody knows why. it is not that I can’t think of an explanation: I can think of too many. Right now I don’t see how to pin one down.
HP: In your opinion, what percentage of scientists are open to discussing ethnicity and intelligence? Who are the worst opponents? Sociologists?
GC: It is complicated by the fact that most people have no understanding of natural selection, even in professions where you might think that they would, such as anthropology or genetics. What percentage of scientists are open to discussion? Couldn’t really say – maybe 10%? In private. Of course most are extremely averse to any hint of realism in this area. Sometimes they splutter. Some are concerned about funding. Others are natural-born liars: S. J. Gould was. Although it was also true that he had no real understanding of natural selection & population genetics. Separating the lies from the ignorance and innumeracy in his work is a real chore.
Fairly often, people lead lives that shield them from some realities. They don’t even know. A friend, a few years ago, was talking with a (troop? herd? swarm?) of genetics grad students: only one of 12 was even aware of the measured IQ differences between blacks and whites in the US.
Sociologists are generally useless, but I’m not sure people listen to them much anymore.
A journalist, Jon Entine, interviewed a lot of biologists about our idea not long after it came out. He said that most thought it was possible or likely. None were willing to go public. I know the details in a few such cases: people who think we’re right, but who wouldn’t want to be quoted. It’s a funny world.
HP: Even more controversial is your theory of homosexuality as a pathogenic disease. Although you have received significant support for this idea from prominent scientists, it seems as though the intelligentsia and public opinion is completely against even a discussion of it? I’ve read that you can never get funding to explore this. Any recent developments?
GC: Nothing much has happened recently: things look mostly the same. It is still the case that identical twins are usually discordant ( ~75% of the time), which strongly hints at some kind of environmental trigger. A big study un-replicated the older-brother effect, so that’s now uncertain.
People like Bill Hamilton saw the pathogen hypothesis as an obviously good explanation once pointed out – hardly proven, but essentially the only plausible idea out there. But there aren’t many people like him. In fact, I’ve had people condescendingly explain to me that homosexuality is a product of kin selection – I told them Hamilton hadn’t thought so, and of course he knew a thing or two about kin selection, having invented the concept.
It is a subject that people feel they have a right to an opinion about, even though it involves technicalities of which they understand nothing. I guess that we should be glad most people don’t have highly emotional, strongly-held views on group theory.
I more feel that I live in a country that’s a lot crazier than it used to be – which is not to say that it was ever perfectly sane. Who is?
HP: Regarding the pathogenic theory of disease, are there any new discoveries in your research? Has it been further linked to cancer? Is there more evidence relating it to ulcers?
GC: Nothing all that spectacular. Let’s see – what has happened over the past decade? The ulcer story seems definitive: they’re rare without h. pylori, which also greatly increases the chance of stomach cancer. HPV (known cause of almost all cervical cancer) has branched out into a major cause of mouth and throat cancer, thanks to oral sex. There’s good evidence of connection between glioblastoma and cytomegalovirus: may well be causal. There is recent work on an unexpected connection between colon cancer: and fusobacterium: this might amount to something.
Patrick Moore, one of the discoverers of HHV8, the virus causing Kaposis’s sarcoma, recently found another: a polyomavirus that causes most cases of Merkel cell carcinoma. There are suspicions about pathogen involvement in atherosclerosis and Alzheimer’s – mainly chlamydia pneumoniae – but the issue is still in doubt.
We know a bit more about the indirect, unpleasant consequences of selection for resistance to infectious disease. We know more about genetic malaria defenses, and recently found that a molecular variant that defends against one of the two major strains of African sleeping sickness increases vulnerability to kidney failure, and mostly explains the over representation of American blacks in dialysis.
Along that same line, recent genetic studies, although they have produce relatively small public health benefits, have made the causes of some diseases clearer. It looks as if Crohn’s disease and ulcerative colitis are caused by the intersection of certain bacteria and an individual with a flawed immune system. Contrariwise, selection for a stronger immune response has increased vulnerability to Type I diabetes among northern Europeans.
I would be happy to be wrong, but more and more it looks to me that most mental illness is the result of mutational pressure. A pathogen is the preferred explanation, because it’s easier to defeat.
HP: I am interested in the notion of “Scientific Topics that Are Taboo.” Other than the two that we have already mentioned: 1) Ethnicity and Intelligence, 2) Homosexuality as a Pathogenic Disease — are there other scientific topics that seem to be off-limits ? Also, are there nations other than the United States where there is more freedom to do controversial research?
GC: Some things are easier in China. Like, for example, having a prisoner shot to get a fresh kidney.
Well, class differences in intelligence are controversial, although they clearly exist. The main obstacles to research in such topics are not religious nuts (people like me): more the attitudes typical of a liberal university graduate. Sometimes there are other reasons. An Israeli evolutionary biologist expressed interest in a big effort to prove or disprove our Ashkenazi hypothesis: the powers that be in Israel were massively uninterested, since it would likely show that there had been strong selection for intelligence in the Ashkenazi (North-European Jews), but not in lots of other Jewish populations such as Moroccan or Yemeni Jews.
HP: What you are most recently working on?
GC: I have been thinking about admixture with archaic hominids like Neanderthals. In our book, we predicted that such admixture happened when anatomically modern humans expanded out of Africa. We showed that individual favorable genetic variants could be picked up very easily with even a smidgen of admixture – and that such favored variants could well have achieved high frequency today, at least in some populations. We argued that this kind of introgression of favorable alleles might be responsible for the cultural efflorescence seen in Upper Paleolithic Europe. Admixture has now been proven (Green et al 2010). A good case has made that most people in Eurasia carry the Neanderthal or Denisovan variants of certain immunological (HLA) genes. As for introgression of Neanderthal genes that influence behavior or cognition, no proof yet, The jury is still out. Having most of your predictions come true can be something of a letdown…
Am also still interested in the evolution of human intelligence, and look forward with interest to some forthcoming genetic measurements that may tell us a lot, none of which anyone wants to hear.