Sex and the Brain

I just noticed an new article in PNAS – research by Daphna Joel a behavioral neuroscientist at Tel Aviv University. Using MRI, she concludes that the brains of men and women aren’t really different. She suggests that the notion that men and women behave differently may be a myth.

She is, of course, utterly full of shit. It’s fountaining out of every pore: her hair will never go gray. We know of many sex differences in the brain – not just volume, not just the fraction of gray matter vs white matter, not just big differences in the incidences of neuropsychiatric disorders like autism and anorexia nervosa. In a few cases (like CAH, or androgen sensitivity, or maybe Turner’s syndrome) we know something about the developmental mechanisms involved. We see analogous differences in animal models: and no, it’s not culture.

If you want to determine a brain’s sex from MRI data (without cheating by looking at the Y chromosome) you build a statistical discriminator – you don’t create a continuum of “femaleness” to “maleness,” for the entire brain and score every individual region-by-region to find out where they fall on that male-to-female continuum.

Moreover, similarity in gross anatomy does not ensure similar behavioral tendencies. If I compared the brain of a pit bull with that of a similar-sized border collie, I doubt if I could see the behavioral differences in the size of the amygdala or whatever. Those behavioral differences exist, they’re innate, they have a physical/genetic basis – but at the moment I couldn’t tell you what brain differences to look for. Could be differences in the distribution of neurotransmitter receptors, or differences in axon length, or dendrite connectivity – lots of things, including many that wouldn’t show up on MRI. Many couldn’t be seen by Ramón y Cajal.

As for her expertise on behavioral differences between men and women – she’s a maroon. Reminds me of John Money, and his crap about how you have to learn to be a boy or a girl. Which he knew was false (David Reimer). She probably thinks Mattel has brainwashed male rhesus monkeys into liking toy trucks.

Posted in Uncategorized | 15 Comments

Low-Hanging Fruit: Ergothioneine

Ergothioneine is an amino acid, one that is made by fungi and some bacteria. Humans can’t make it, but it is present in some tissues at fairly high level, and there is a specific transporter (SLC22A4). A more-active form of that gene has been favored by positive selection in Europeans: this could be related to a mostly-wheat diet, since wheat has very little ergothioneine.

A better ergothioneine transporter increases fitness by a few percent, else we wouldn’t have noticed the selection pressure. If logic worked in in biology, we could conclude that ergothioneine is good for you – a vitamin, even though we don’t understand what it does, or the negative consequences of a deficiency. At least some people must have such a deficiency – maybe we should look at people with knocked-out SLC22A4? And if we can’t find any, that says something, eh?

of course, anyone that decided to work this problem – one that we know for sure is relevant to human health – risks the ignominious fate of Adolf Windaus and Albert Szent-Györgyi.

Posted in Uncategorized | 24 Comments

Degenerate Hobbits

There’s a new report out, claiming that the Flores Hobbits are probably an island dwarf version of Homo erectus, judging by their teeth.

Flores isn’t a very big island – ~5,000 square miles, similar to Connecticut. There couldn’t have been many hobbits. And they seem to have been there for a long time, hundreds of thousand of years, judging from tools found.

Which means that if they were what they seem to be, they would have suffered far more from genetic load than Neanderthals or Denisovans. All those problems of slightly deleterious alleles drifting to high frequencies would be much more serious, and the probability of salvage mutations would be much lower.. Moreover, the Flores Hobbits look screwed up (unlike Neanderthals), with many skeletal anomalies and asymmetries. This is why some anthropologists have argued that they are just diseased modern humans.

Point is, the island-dwarfed erectus story does makes sense, but it would inevitably result in them being highly screwed up. Like they are. I talked about this several years ago – “Back to the Trees” – and suggest that they might have suffered from partial mutational meltdown – too much load to have an efficient brain. The skeletal anomalies suggest that their load was pretty serious.

Posted in Uncategorized | 33 Comments

Hive Mind

Garrett Jones has a new book out: Hive Mind. He argues that “while individual IQ scores predict our independent success moderately well, a country’s average score is a remarkable bellwether of its general prosperity.” Makes sense. I might even call it obvious.

More on that later.

Of course there are other general factors that create differences in national prosperity – the biggest are valuable natural resources (oil in Saudi Arabia) and being currently or recently under a Communist* government. But average national IQ has the largest effect. I didn’t see much direct discussion of this, but this general trend was a lot less true at points in the past. The Communism ref is a hint: there used to be a lot of Communism, now there’s not – this makes the relative importance of IQ differences larger than it was in 1970. Generally, you could say that most of the world has signed on to roughly the same form of economic organization, just as statesmen everywhere wear suits, so that differences in national prosperity have more to do with differences in biological capital than they used to – just as differences in individual height are more driven by genetics today, in the US (where we are fat), than they were in England in 1800 (where the poor were hungry and five inches shorter). Not than biological difference were ever unimportant.

Jones talks about IQ – what it is, what it predicts. He knows his psychometrics, which is damned unusual for an economist. You would almost think that he’s spent a lot of time (sub rosa) conferring, conversing, and otherwise hobnobbing with devotees of the Dark Arts. He talks about how nice it would be if we could raise national IQs (then Indonesia could do what Germany does – and did) – but of course we don’t really know how, except with iodine supplementation.

He talks about the ways in which a higher national IQ pays off – more patience (low time preference), higher savings rates, more cooperation, more ability to form teams suited to complex tasks with little room for error, less incompetent government. I’d also mention differences in inventiveness, a higher fraction of people that exceed required thresholds for complex tasks, more people believing in and practicing basic maintenance (zero or crappy maintenance is the bane of the Third World), more effective deterrence of crime, fewer accidents, etc etc. If you’re ever watched a decent but dumb guy confidently fire a nail gun into the palm of his own hand, you will know what I mean.

Of course, he doesn’t mention how higher IQ increases susceptibility to various kinds of nuttiness, which can have substantial economic costs. Just to make it clear, I have no doubt that the average Ivy League graduate would be less likely than the average graduate of State U to agree with the major thesis of this book. Probably if you stated the conclusions sufficiently trenchantly (Haiti is fucked-up because Haitians are dumb!) they would violently reject his thesis. Not literally violently, because I doubt if the average Harvard graduate actually knows how to tar and feather anyone, but they would try to hurt his feelings. And get him fired, of course.

The icing on the cake is the policy prescription: since we know that higher average IQ is a good thing for a country, it behooves us to let in lots and of low-IQ immigrants – which will leave us more prosperous! Jones stomps on the dick of his own argument with hobnail boots, in a fashion I have only seen matched by Jared Diamond’s claim that every population on Earth has the same average IQ, except for Melanesians in PNG, who are smarter, presumably because of their Denisovan admixture.

Does he worry about the fact that we live in a welfare state, and that low-income immigrants (on average) soak up a lot more money over a lifetime than they will ever contribute to the Federal coffers? Not one bit. This is just as true for England and France and Sweden. Reminds me of the scramble for Africa, in which every colony was a money-loser, but no European country could do without some. He worries a little about furriners bring along their noxious political traditions – but Bryan Caplan assures him that they’ll pick up our political notions, in the same way that Bryan Caplan thinks and talks about politics just like an old Midwestern farmer.

Think of it this way: some of the products of an advanced technological civilization are generally valuable and cheap. They can and are used by poor countries as well. I’m thinking things like vaccines, and penicillin, and right turn on red. But they can’t be used unless someone invents them, and that happens less as the national IQ drops. Maybe we need to leave at least one major advanced country alone, not fucking it up any  more than it already is, so that on those odd occasions where actually getting something right matters, humanity has at least a Chinaman’s chance.

I said earlier that the general conclusion was obvious, but I’m using that word with no meaning again. If you have a reasonably detailed picture of the world – sure it’s obvious. If you talked to a smart, fair-minded guy in 1900, one with wide experience, and asked which countries would do well if native ability were the main determinant of national success – I think he would have predicted something roughly like what we see today. It’s highly correlated with peoples that managed fairly high levels of sophistication since the Bronze Age**.

If it’s all that obvious, why haven’t other economists come to similar conclusions? Because they didn’t like these conclusions, of course – because of professional risk – because they don’t have a reasonably detailed picture of the world – because they never bothered to learn anything about psychometrics.  Look at the reaction of the economists to Lynn and Vanhanen’s work: puerile.

* Mainstream economists weren’t any too good at noticing that Communism fucks you up , although I think they saw that living over an ocean of oil paid off. Only one out of the three major factors understood – not good even by Meatloaf’s standard.

** Which Jared Diamond noticed, and which makes no sense in his explanatory framework. “The nations rising to new power are still ones were incorporated thousands of years ago into the old centers of dominance based on food production, or that have been repopulated by peoples from those centers.”

Posted in Uncategorized | 146 Comments

Perverted Frogs

Pedophylax esculentus is a common type of frog in Europe. It originated as a hybrid of two other frog species (P. ridibundus (RR) and P. lessonae (LL) ), but that’s not their fault. However, the way in which they continue the species is genuinely embarrassing, almost as bad as puppeteers.

P. esculentus ( genome RL) generally produces offspring by mating with another species, usually P. lessonae. In most populations, they produce gametes that only contain the R genome (the L genome is discarded): mating with P. Lessonae restores the L genome. Presto, more hybrids.

They can mate with others of their kind, but few tadpoles survive – essentially because the parental genome (R) does not go through sexual recombination – thus mutations have accumulated over the many generations since the original hybridization. Muller’s ratchet.

In eastern Europe, it’s the other way around: the L genome is clonal and the hybrids have to mate with P. ridibundus, with complex results (3/4 hybrids, 1/4 pure ridibundus).

And then some populations manage with a mix of diploid and triploid hybrids, which we’ll leave as an exercise for the reader.

Anyhow, the truly weird thing is, people eat these things.

Posted in Uncategorized | 14 Comments

Monte Verde, Ghost populations, Brazil

There is a new report about Monte Verde, an archaeological site in Chile. There is solid evidence that people were there 14,500 years ago – the earliest occupation of South America that we can be sure of – older than the Clovis culture of North America!

Further work, just published, suggests that there are artifacts at Monte Verde that are at least 18,500 years old. John Hawks talks about it, here

Remember also that A. there is a genetic evidence of a ghost population in some Amerindian groups, a population most closely related to the Onge (Andaman islanders), but also to other groups such as Melanesians and Philippine Negritos (Mamanwa). This component makes up one or two percent of the ancestry of Amazonian Indians. Also consider that the earliest known skeletons in the Americas, especially in Brazil, look a lot like Australo-Melanesians. Although I don’t we think we have any ancient DNA from those Brazilian skeletons yet.

It seems possible that a vaguely Andaman-like population, using a maritime strategy, crossed into American waters, moved down the Pacific coast, and eventually settled inland South America, well before the Amerindians we known showed up at Ellis Island. John talks about them “following the kelp road”.

There is another fact that helps in knitting these observations together. When in doubt, look at the map – it often tells you something.


Thing is, if you arrived so early, when deglaciation had barely begun, North America was a pretty crappy place, ice in Chicago and taiga down to the Gulf Coast. While on the other hand, parts of Brazil were pretty decent habitat for hunter-gatherers.

Suppose this happened. These guys didn’t start out as experienced big-game hunters. The Amerindians, originating in Beringia, were. So these hypothetical sort-of-Andmananese took a while to adapt to a continental lifestyle and never became awesome, extinction causing hunters. Their tool kit looks pretty simple.

You might compare them to the Australo-Melanesians that occupied Southeast Asia, before people from South China moved in and squashed them (with some admixing).

Here is looks like replacement by Amerindians with just a little admixture. Those Amerindians could easily spread over North America – they were good hunters and the climate was much improved by then.

How to tell if this story is correct? if we find a sufficiently old (C-14 dating) skeleton in Central or South America that has vaguely-Andamanese DNA, rather than Amerindian autosomal, we’ll know. Would take only a sliver of bone.

Posted in Uncategorized | 29 Comments

Clever Sillies

I don’t have good numbers on this, but I often get the feeling that bright people are particularly susceptible to moderately complicated intellectual scams, like Marx and Freud and foot reflexology. By the way, I would guess that you all have noticed that foot reflexology teaches that each part of the body has an image on the sole of the foot – logically this must include an image of the foot itself! Brouwer! Quaker Oats Box!

I would like to have more certain, more quantitative knowledge about this (about clever sillies, although the foot thing is also interesting)

Anyhow,I was reading a post by by Scott Aaronson (a smart guy) about silly nomenclature in the “social sciences”, which touched upon past delusions of this sort- but with the implication that Scott probably wouldn’t have succumbed to such nonsense. But I kinda think he would have, considering that he takes modern feminism seriously, enough so to have asked a therapist to chemically castrate him, since he was such a threatening, yet miserable, tool of the patriarchy.

But, as I said, he’s a bright guy: why did he ever believe any of this shit? Why would he ever have taken feminism seriously? Roughly speaking, you can factor an ideology into a statement of preferences and a theory of the world, usually one that can be inscribed on a 3″ x 5″ card: I cannot think of any example in which feminism’s index card ever showed any predictive power at all (male rhesus monkeys prefer toy trucks, for example) . I mean, Andrea Dworkin, really?

I’m pretty sure that an unusually high fraction of high-achieving types in math and physics show a funny, low-fitness personality, but that’s something different, I think.

Posted in Uncategorized | 164 Comments