Razib Khan One-stop-shopping for all of my content

June 30, 2010

Daily Data Dump – Wednesday

Filed under: Blog,Daily Data Dump — Razib Khan @ 1:46 pm

Psychological Research Conducted in ‘WEIRD’ Nations May Not Apply to Global Populations. This is the standard objection to psychological studies in terms of the representativeness of their samples; middle class university students. But more broadly they’re Western middle class university students.

The grandmother factor: Why do only humans and whales live long past menopause? Interestingly the data and model here imply that the importance of disproportionate maternal grandmothers (this is empirically attested in even notionally patriarchal societies) may have something to do with patrilocality.

Ghana’s unique African-Hindu temple. In some ways this seems to replicate the non-congregational model found in India, whereby locals seem to be patronizing the temple for its “services” is a non-exclusive fashion.

The Myth of the Fat Burning Zone. This is in the “news your can use” category.

Why won’t those &$*%#@ bloggers go away? Scott Sumner’s response to a criticism of the “econosphere” from a professional economist. I doubt that engineers worry about engineering bloggers talking about stuff they don’t know about. Economics is hard, but many of us who are not averse to giving due respect to professionals who have a real understanding of how the world works have shifted our assessment on the empirics of late. The econosphere would disappear in its current critical form if economists either toned down their pretensions, or actually showed us the money.

June 29, 2010

Porn and moral panic

Filed under: Culture,Porn,Psychology — Razib Khan @ 3:41 pm

Social conservative blogger Rod Dreher points me to this interview of a Left-wing sociologist on the malevolent influence of pornography on modern relationships. She has a book out, Pornland: How Porn has Hijacked our Sexuality. Her conclusion:

To turn this around there needs to be a massive public health awareness campaign. Unless people begin to understand the role pornography is playing in our culture, I can’t see any reason that this won’t get worse, because all of these men who started watching pornography young are going to want more and more. Pornographers themselves say they’re having trouble keeping up with what fans want because they want it so hardcore.

Where is this going to end? I don’t know. What will an 11-year-old boy want 10, 20, or 30 years from now? Nobody knows. The truth is we’ve never brought up a generation of males with hardcore pornography. No one can really say what’s going to happen. What we do know, from how images and media affect people, is that it’s going to increasingly shape the way men think about sex, sexuality, and relationships.


A lot of the rest of the interview is going to, or not going to, make sense depending on your priors. Just as Christian evangelical psychotherapy, or a rabbi making a ruling based on the halakhah, uses terms and logics which may seem totally meaningless to outsiders, so people trained in sociology operate in their own lexical universe which operates in a parallel empirical world (when I actually spent some time around young evangelical Christians I recalled that they often interspersed their banal conversations with phrases such as “glorifying God,” or “glorifying my Lord and Savior,” which seemed to have a lot of meaning for them, even if it was about their workout regime*). As an intellectual exercise I often take an interest in what sociologists say, but it’s equivalent to theology as far as I’m concerned insofar as it makes any pretense to mapping onto reality. In contrast, I think economists are guilty of hubris and error, but they at least aim for some clarity so you know when they’re wrong. I am here thinking of Noam Chomsky’s attitude toward Post Modernism.

On a personal note I come from a generation which spanned the period when pornography was scarce, and when it was ubiquitous. It’s an empirically correct observation that it takes two seconds to find extremely disgusting fetish material, whereas before the internet you may not even have been aware of the existence of whole genres of pornography! A case in point, I did not know of the existence of bestiality until I was sixteen years old (a friend took me to a Christian youth group meeting, and the pastor started talking about all the disgusting perverted things you weren’t supposed to do, but he had to define a lot of it in the process). A few years after I happened to walk by a computer in a family room, and I saw that an eight year old boy was deleting disgusting fetish porn spam from his Hotmail account! What had been beyond the ken of my comprehension even into adolescence was a nuisance for this individual in their elementary school years.

Over the past 15 years we’ve run a massive sociological experiment in the United States of America. A whole generation has grown up with easy access to hardcore pornography. Many of the boys exposed in the 1990s are now 30 and older, and starting families. And yet violent crime is still declining in the United States, including rape. There is also no robust evidence that the youth of today are more sexual than those of the past.

That’s why I say that the sorts of sociologists profiled above live in a parallel world, where porn is a primary determinant of the decline in morals in manners. They wouldn’t say morals and manners, but I think that’s what really going on, and explains the attraction of social conservatives like Rod Dreher to the Left-wing critiques. The terminology may differ, but it isn’t too hard to do a search & replace across the arguments and see that they have a similar structure. There was in the past, in some idealized nation, a world of companionate partnership from which we’re declining. In the details the ideal partnership of a Left-wing feminist sociologist and a socially conservative Christian obviously differs a great deal, but both feel besieged by the destabilizing and amoral impact of technology and capitalism, which is saturating us with choice, information and plenitude of perversion.

The repulsiveness of modern pornography is not a trivial matter. I do believe that societies need values, that we’re not simple pure hedonic machines (this is a matter of aesthetics and taste, some may differ as to the necessity of this binding of values). But we need to keep some perspective. Foot binding, corsets and shotgun marriages were parts of the cultural landscape in the past, without the influence of porn. More fundamentally I think Left-wing and conservative critiques of the modern culture of pleasure are overly alarmed because they neglect the biologically rooted essentialist aspect of the experience. Porn arouses despite the fact they’re pixels on the screen. But it is no substitute for a real flesh & blood person, because the essence of the source of the pleasure matters. Some social conservatives worry that the youth will be “converted” to homosexuality. The mainstream generally rejects this perspective as ludicrous on the face of it. Graphically, consider the prospect of a straight male receiving oral sex from a male as opposed to a female. On low-level hedonic grounds one would assume that there is no distinction, but many would demur and say that it was “different.” Similarly, pornography can never replace a real relationship.

Technology and the market, the radical and rapid turnover over lifestyles and choices, make people rightly fearful. But as I suggest above despite our biologically rooted fear of change things are getting better. Of course not all change is always for the good, but to actually differentiate the good from the bad, we need to remain rooted in the real world.

Note: Most of the studies I’ve seen which show that perverts have viewed the grossest of porn don’t establish the arrow of causality. That is, if you’re a pervert obviously you are going to seek perversion by definition. Though arguably exposure to perversion can render you a pervert, I see no reason why this has to be the null.

* The sacralization of all aspects of life is not exceptional or atypical, I simply observe that a lot of the references to it operate in its own universe of meaning which is pretty opaque to outsiders.

Nazis in space

Filed under: Films,Movies,science fiction — Razib Khan @ 11:19 am

Really interesting trailer for a movie which is premised on a “secret history” where a group of Nazis flee to the far side of the moon at the end of World War II, and are returning imminently in the near future from their exile.

Wired has the back story of how this group of film makers generated broad-based funding for their project. Of course they’re Finnish….

Daily Data Dump – Tuesday

Filed under: Blog,Daily Data Dump — Razib Khan @ 10:59 am

North America’s First Peoples More Genetically Diverse Than Thought, Mitochondrial Genome Analysis Reveals. The paper is free to all. Remember that this is just mtDNA, the maternal lineage. This area seems a bit confused now. The standard simple model, which is barely even a ’stylized fact’ at this point, is that a group of Siberians arrived ~12,000 years ago and this founder population to led to all that has come after. For about twenty years geneticists have been claiming to see more time depth, but that’s confused by the possibility that they have been looking at evolutionary dynamics in Berengia, not North America.

In Ireland, a Picture of the High Cost of Austerity. So was there an alternative to austerity for Ireland alone? Can such a small nation pump growth with deficit spending if its larger neighbors are all beating the drum for austerity? Seems like they’re soldiering on and making the best of a bad situation.

In Faulty-Computer Suit, Window to Dell Decline. Dude, do not buy a Dell!

The Triumphant Decline of the WASP. Noah Feldman basically concedes that WASPs are the world’s least primitive population. Of course that does not entail fitness of genes or memes.

Can linguistic features reveal time depths as deep as 50,000 years ago? Mostly likely not.

Your genes are just the odds

Filed under: Behavior Genetics — Razib Khan @ 3:55 am

Morning Edition has a strange story today about the exploration of one neuroscientist of his own family’s history, specifically its psychological and neurological quirks. To not put too fine a point on it, the scientist in question finds out that he has a history of violence in his family, and, that he carries a genetic variant implicated in violent behavior under particular conditions, as well as telling neurological patterns found among psychopaths. Here’s the relevant section:

After learning his violent family history, he examined the images and compared them with the brains of psychopaths. His wife’s scan was normal. His mother: normal. His siblings: normal. His children: normal.

“And I took a look at my own PET scan and saw something disturbing that I did not talk about,” he says.

What he didn’t want to reveal was that his orbital cortex looks inactive.

“If you look at the PET scan, I look just like one of those killers.”

Fallon cautions that this is a young field. Scientists are just beginning to study this area of the brain — much less the brains of criminals. Still, he says the evidence is accumulating that some people’s brains predispose them toward violence and that psychopathic tendencies may be passed down from one generation to another.

The Three Ingredients

And that brings us to the next part of Jim Fallon’s family experiment. Along with brain scans, Fallon also tested each family member’s DNA for genes that are associated with violence. He looked at 12 genes related to aggression and violence and zeroed in on the MAO-A gene (monoamine oxidase A). This gene, which has been the target of considerable research, is also known as the “warrior gene” because it regulates serotonin in the brain. Serotonin affects your mood — think Prozac — and many scientists believe that if you have a certain version of the warrior gene, your brain won’t respond to the calming effects of serotonin.

Fallon calls up another slide on his computer. It has a list of family members’ names, and next to them, the results of the genotyping. Everyone in his family has the low-aggression variant of the MAO-A gene, except for one person.

“You see that? I’m 100 percent. I have the pattern, the risky pattern,” he says, then pauses. “In a sense, I’m a born killer.”

Fallon is being a bit dramatic for effect obviously, but as I said to Eric Michael Johnson this is like finding out you have a history of alcoholism in the family, as well as a genetic variant which results in the less efficient metabolization of alcohol. You know what you know, and you know what you have to do to not put yourself in a position where your predispositions could mix with a dangerous set of choices.

Going back to this example and being more practical, what if behavior genomics and neuroscience advance to the point where you can find out the odds of your child having issues with impulse control, heightened aggression, and reduced independent ethical judgement (e.g., guilt as opposed to shame) are all greater than than expectation. All things being equal the research is telling you that instead of having a 0.1% chance of landing in jail for violent crime, your offspring has a 5% chance. There are all sorts of things you might do, and choices you might make. If, for example, you yourself know that guilt is just something you aren’t heavily gifted with, and that gets you intro trouble in the long term (as you make a sequence of ‘rational’ unethical choices on a regular basis), you might choose a profession which is very transparent so that you don’t have to make ethical decisions on a regular basis where short term self-interest is in conflict with long term self-interest & socialized conceptions of right & wrong. Go into finance if you can do math. Become a lawyer if you can’t.

June 28, 2010

Daily Data Dump – Monday

Filed under: Blog,Daily Data Dump,Links — Razib Khan @ 12:36 pm

High Rates of Sexually Transmitted Infections Among Older Swingers. This goes into the “they had to do research!?!?!” category. Older swingers are a “high risk” group, like gay men and prostitutes.

Golly, Beav, We’re Historic. I really loved Leave It To Beaver when I was a kid.

Religious Extremists Will Inherit the Earth. John Derbyshire reviews the new book Shall the Religious Inherit the Earth?: Demography and Politics in the Twenty-First Century. I’m looking forward to this book, though I’m generally skeptical of the error bars on any social prediction beyond the 20 year time horizon.

Born to be a slave in Niger. This a story from 2005, but from what I gather nothing has really changed in much of the Sahel since then. Slavery is particularly pernicious in Mauritania, where the racialized aspect is pretty straightforward.

New Clues Suggest Wet Era on Early Mars Was Global. This story caught my attention because I just found out that Edgar Rice Burrough’s first Barsoon novel is going to be turned into a film.

More children please: men or women?

Filed under: Data Analysis,Feminism,GSS,Pro-Natalism — Razib Khan @ 12:49 am

In the post below on Bryan Caplan’s arguments for why one should have more children there was an “interesting” comment:

As if we’re harmless little creatures at one with our environment and put no toll on the balance of nature around us. Funny how we humans act like mindless rabbits and lemmings and put the sole unintelligent directive of our DNA as the mouth of god. Men most interestingly in power or self described intellectuals after sitting around picking belly lint and jerking off in praise of their penises find clever monkey justifications (patriarchal religions mostly) for more more more babies and women must be subservient to male sexual needs and demands of more babies. See a huge male god said so.

Funny how women mostly never jump on the soapbox bandwagon of wanting to pop out tons of kids, just male spermatozoa fed rants formed by the human male organism to insist his natural inclination is the word of gawd. If you can’t use holy massive penised Jehovah to instill this dreck then dream up socio-biological propaganda for the atheist hip guys needing a good shagging with their female cohorts.

Ignoring the weirdness of much the comment, is it true that men are more pro-natalist than women? I have shown that there seems to be a trend within the last 10 years of preference for larger families. What’s the sex breakdown for this?

The correlation between men and women is 0.65 year-to-year in their mean for ideal number of children. About 43% of the variance of the trend over the years can be predicted from one sex to the other. Is there is a systematic difference? Here’s a chart:

fertscreen

The period before 1998 is rather noisy overall. The correlation actually increases after ‘98 because of the concurrent upward trend. That being said, it looks like the pro-natalist bias is more accentuated among women than men. If I constrain the years to the 2000s, and age range to 18-30, the mean ideal number of children for men is 2.88 and for women it is 3.03.

These data indicate that in fact Bryan Caplan marches with the sisterhood on this issue.

June 27, 2010

The two cycles

Filed under: China,civilization,Culture,History — Razib @ 12:05 pm

I’m reading Brotherhood of Kings: How International Relations Shaped the Ancient Near East. The book basically outlines the international state system in the ancient Near East which fostered diplomatic relationships between the monarchies of the period. It is noted that this state system and diplomatic culture did not make it through the chaos which marks the transition between what we term the Bronze Age and Iron Age; the centuries between 1200 and 600 BC. I try and read about the ancient Near East when I can, it’s a hard area to find academic books accessible to lay people (I don’t know Sumerian or Akkadian for example, which means that a lot of the philological stuff goes over my head). But thanks the usage of cuneiform tablets which are often well preserved when palaces are burned down we have a substantial amount of records, albeit not of the personable narrative form excluding some exceptions (good for economic historians, not so much for cultural historians).


One thing that seems to jump out to me is that our history can be divided between what came before the transition above, and what came after. If you know about Julian Jaynes you know some argue for a really deep psychological chasm. Setting that aside, consider the cultural continuity of texts between the period after, and the period before. Much of what we know of antiquity in the West is due to translation efforts during the Carolingian period, encyclopediasts in 10th century Byzantium, and the Abbasids in 9th century. These are the major choke points. If it were not for these periods of elite sponsorship of transcription we would be much poorer in antique Greco-Roman works (the maligned Assyrian Empire played that role in the early Iron Age; I believe we have the Epic of Gilgamesh thanks to its libraries).

The cultural chasm between Mycenaean Greece and Classical Greece, a period of 500 years, is arguably greater than that between Classical Greece and 6th century Byzantium. After 1200 BC literate culture disappeared from the Aegean and Anatolia. The societies of the Near East and Egypt were under extreme stress, and their survival was a near thing. Literacy had long disappeared from India (assuming that the Indus Valley script is a full-fledged script, something I suspect it is simply because the society seems too complex and expansive for it not to have more than accounting notation). Western and Indian writing systems derive from the alphabets of the Levant. If the Near East and Egypt had descended into pure barbarism, with Assyria and Egypt being swallowed up in the sea of illiteracy, what would the present look like?

China is the arguable exception to this trend, even though there was a transition from the Shang to the Zhou, I do not know of a major cultural regress during this period in the Far East. Greece remained in a decentralized pre-literate state for centuries. If the West  persisted in such a state for far longer what would that mean for us? The Persian Empire, which had control of Central Asia, depended to a large extent on co-opting the political and cultural systems preexistent across its domains. If these regions had remained in a state of barbarism long enough it may be that Chinese culture hegemony in Central Asia would have been robust enough to withstand all the subsequent historical shocks, and world history would look far different.*

* In the period between 0 and 1000 AD Central Asia was contested between China and the Western Eurasian societies. After 1000 AD Central Asia became more fully integrated into Western Eurasian civilization as China withdrew back beyond its geographical perimeter.

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The two cycles

Filed under: China,civilization,Culture,History — Razib Khan @ 12:05 pm

I’m reading Brotherhood of Kings: How International Relations Shaped the Ancient Near East. The book basically outlines the international state system in the ancient Near East which fostered diplomatic relationships between the monarchies of the period. It is noted that this state system and diplomatic culture did not make it through the chaos which marks the transition between what we term the Bronze Age and Iron Age; the centuries between 1200 and 600 BC. I try and read about the ancient Near East when I can, it’s a hard area to find academic books accessible to lay people (I don’t know Sumerian or Akkadian for example, which means that a lot of the philological stuff goes over my head). But thanks the usage of cuneiform tablets which are often well preserved when palaces are burned down we have a substantial amount of records, albeit not of the personable narrative form excluding some exceptions (good for economic historians, not so much for cultural historians).


One thing that seems to jump out to me is that our history can be divided between what came before the transition above, and what came after. If you know about Julian Jaynes you know some argue for a really deep psychological chasm. Setting that aside, consider the cultural continuity of texts between the period after, and the period before. Much of what we know of antiquity in the West is due to translation efforts during the Carolingian period, encyclopediasts in 10th century Byzantium, and the Abbasids in 9th century. These are the major choke points. If it were not for these periods of elite sponsorship of transcription we would be much poorer in antique Greco-Roman works (the maligned Assyrian Empire played that role in the early Iron Age; I believe we have the Epic of Gilgamesh thanks to its libraries).

The cultural chasm between Mycenaean Greece and Classical Greece, a period of 500 years, is arguably greater than that between Classical Greece and 6th century Byzantium. After 1200 BC literate culture disappeared from the Aegean and Anatolia. The societies of the Near East and Egypt were under extreme stress, and their survival was a near thing. Literacy had long disappeared from India (assuming that the Indus Valley script is a full-fledged script, something I suspect it is simply because the society seems too complex and expansive for it not to have more than accounting notation). Western and Indian writing systems derive from the alphabets of the Levant. If the Near East and Egypt had descended into pure barbarism, with Assyria and Egypt being swallowed up in the sea of illiteracy, what would the present look like?

China is the arguable exception to this trend, even though there was a transition from the Shang to the Zhou, I do not know of a major cultural regress during this period in the Far East. Greece remained in a decentralized pre-literate state for centuries. If the West  persisted in such a state for far longer what would that mean for us? The Persian Empire, which had control of Central Asia, depended to a large extent on co-opting the political and cultural systems preexistent across its domains. If these regions had remained in a state of barbarism long enough it may be that Chinese culture hegemony in Central Asia would have been robust enough to withstand all the subsequent historical shocks, and world history would look far different.*

* In the period between 0 and 1000 AD Central Asia was contested between China and the Western Eurasian societies. After 1000 AD Central Asia became more fully integrated into Western Eurasian civilization as China withdrew back beyond its geographical perimeter.

Psychometrics, epigenetics and economics

Filed under: IQ,Psychology,Psychometrics — Razib Khan @ 10:26 am

Two papers of interest. IQ in the Production Function: Evidence from Immigrant Earnings (ungated). And Human Intelligence and Polymorphisms in the DNA Methyltransferase Genes Involved in Epigenetic Marking. My impression is that the focus on epigenetics has a higher-order social motive; even the sort of humanists who are involved with N + 1 have asked me about the topic. But how many people know what methylation is?

Why educated women are having children

Filed under: Culture,Data Analysis,Education,natalism,Women — Razib Khan @ 9:22 am

Matt Yglesias has posted some charts showing that

1) Childlessness among women is becoming more common

2) The variation of this state by education is disappearing

Here’s the chart which illustrates the second phenomenon:

758-2

I think the reason this may be occurring is a dilution of the sample bias of women who have higher education in relation to the general ppoulation. In other words, as more women attain advanced degrees the pool of those women become less atypical vis-a-vis the general population

To gauge the shift in education and peculiarity I only needed a few variables in the General Social Survey. I limited SEX to women, YEAR to 1992-1994 and 2006-2008, DEGREE allowed me to break down educational attainment, and finally GOD was a variable which probed them on a culturally indicative variable.

First you can see women as a whole have become more well educated. This is a well known dynamic. The absolute change in the proportion of women who have advanced degrees is small, only a few percent, but in the GSS the proportion increase is around 50%. This includes masters and doctorates into one category.

womeedu

The sample sizes for GOD across the periods of interest are small, but look at the enormous increase in the proportion who have no doubts in the existence of God. There was no change in this result in the general population across this time period.

womegod

UPDATE: For the second chart I forgot to note that that’s only women with advanced degrees.

Amerindians of Brazil more numerous than you think

Filed under: Amerindian,Brazil,Culture,Genetics,Genomics,Mixed-Race — Razib Khan @ 8:09 am

adriana-limaA few months ago I was thinking a fair amount about the Neandertals. One issue which became more stark to me due to that particular finding, that a few percent of the human genome seems to have derived from Neandertal populations, is the reality that genetic distinctiveness can persist long after cultural coherency is no longer a reality. That made me reconsider one of the facts of contemporary scholarship, that the Amerindian populations of the two most populous nations of the New World, the United States of America and Brazil, have disappeared or been totally marginalized demographically.

I’ve observed before it looks like that about 15-20% of the ancestry of the Argentine population is Amerindian, despite the nation’s proud identity as a European settler offshoot (i.e., more like the United States or Australia, than Mexico, which has an explicit hybrid identity). But I realized that Brazil was perhaps the bigger catch.

Only 0.4% of Brazilians identify as Amerindian. That’s about 700,000 people. But we know that a substantial number of white, brown and black Brazilians have Amerindian ancestry. Assuming for argument’s sake that the 700,000 Amerindians have undiluted indigenous ancestry, how much of the distinctive Amerindian genome in modern Brazil is to be found in this segment of the population?

There was a paper which came out in an obscure Brazilian journal last year which can help answer this question, DNA tests probe the genomic ancestry of Brazilians. For the purposes of the paper they needed to find a small number of ancestrally informative markers which would allow them to partition the ancestries of the individuals in their data set into European, African, and Amerindian, segments. Luckily these are three very distinctive populations. They cross-checked the utility of their markers against the HGDP data set. In other words the precision and accuracy of the 40 markers they selected should be assessed by how well they can distinguish these three “pure” populations. Their Brazilian subjects consisted of self-identified whites from various regions, as well as black men from Sao Paulo. Brazil’s racial taxonomy has a brown (pardo) category which is large, but judging from the very high proportion of African ancestry among the blacks in their sample I don’t think they included self-identified mixed-race people in that group (some scholars lump mixed and black Brazilians together into the black category).

First, let’s see how well the markers allow for us to distinguish populations’ whose ancestry we’re pretty sure about.

7913i02

No that bad. Observe the trailing off of Europeans and Amerindians along their axis of variation. From previous papers using SNP chips with hundreds of thousands of markers It seems that the HGDP Amerindian sample has non-trivial European ancestry, so it isn’t just a limitation of their marker set. This shouldn’t be that surprising in light of the history of Latin America, and the centuries of racial fluidity which occurred. Additionally, I assume that it would be more difficult to find markers which vary between Europeans and Amerindians than between these two groups and Africans (remember that Africans have more genetic diversity, and non-African populations can be thought of as simply one branch out of Africa).

The following chart shows the outcome from the markers across various regions of Brazil. I assume that the core American readership will be pretty ignorant of the regions, so this map will help. Southern Brazil is white. The rest of the country far less so. Gisele Bündchen and Alessandra Ambrosio are from Rio Grande do Sul in the far south. Adrianna Lima, pictured above, is from Bahia in the northeast. All of the panels are for whites (through self-identification) except for the last.

7913i03

Despite the limitations of 40 markers I think the results here are probably pretty good. The South region has the whitest whites. This was an area with massive immigration, and fewer non-whites to start with. It is in the northeastern region that you see more Amerindian than black ancestry among the whites. From what I have seen in other papers the brown category in Brazil is more skewed toward European ancestry than panel F, so that’s why I assume that these are men who self-identify as black.

But for the purposes of my original question we need to assess ancestral contributions within these groups from Amerindians. The following table does just that.

7913t01

The authors note a curious fact: there’s no statistically significant difference between the regions in terms of Amerindian ancestry for self-identified white Brazilians. This resembles the pattern we saw with Neandertal admixture, and I assume the explanation is the same: the integration of Amerindian ancestry occurred early in the history of the white Brazilian population and has now distributed throughout it via generations of intermarriage except for those with undiluted white immigrant heritage (e.g., Gisele, who comes from a German town). The figure for blacks from Sao Paulo is about the same as whites as well.

Let’s assume 10% Amerindian ancestry and 200 million Brazilians to make the math easier. Since it is about 10% in whites and blacks, I suspect it will be 10% in those who identify as mixed race as well. Where does that leave us? That would mean 20 million Brazilians of Amerindian ancestry! As you can see around 95% of the Amerindian genome in Brazil is found among those who do not self-identify as Amerindian.

For Americans (citizens of the USA) it is then interesting to wonder how much of the Native genome is found in whites, particularly old stock colonial descended whites, and how much in self-identified Native Americans. Looking at the genetic studies I believe that the Amerindian proportion is much lower among white Americans than 10%. Additionally, while 700,000 Brazilians identify as Amerindian, 2.4 million Americans do (though I believe that a much larger proportion of American Native Americans are of mixed ancestry than Brazilian Aboriginals). I think that the odds are that more ancestry which is pre-Columbian in the USA does reside within the white population than within the self-identified Native American tribes, but it may be a close thing. And of course there are Latino populations which need to be added into the equation, whose Amerindian ancestry is significant (in the case of Mexican Americans possibly preponderant), though it is of Mesoamerican origin.

But doing those sums is for another post.

Note: A preemptive apology to those who feel I’ve used the wrong term for any particular ethnic group. I have preferred the more Politically Correct (though less popular) term Native American in the context of the USA, but feel that Amerindian is technical or scholarly enough to evade charges of insensitivity.

Image credit: UnaFraseCelebre.com

June 26, 2010

Tick-tock biological clock

Filed under: Medicine,Reproductive health — Razib Khan @ 11:46 pm

There will be an interesting presentation tomorrow at the European Society of Human Reproduction & Embryology. Basically the researcher is going to present on a method for predicting when a woman will hit menopause. This part from the press release is the important bit:

“The results from our study could enable us to make a more realistic assessment of women’s reproductive status many years before they reach menopause. For example, if a 20-year-old woman has a concentration of serum AMH of 2.8 ng/ml [nanograms per millilitre], we estimate that she will become menopausal between 35-38 years old. To the best of our knowledge this is the first prediction of age at menopause that has resulted from a population-based cohort study. We believe that our estimates of ages at menopause based on AMH levels are of sufficient validity to guide medical practitioners in their day-to-day practice, so that they can help women with their family planning.”

The method:

By taking blood samples from 266 women, aged 20-49, who had been enrolled in the much larger Tehran Lipid and Glucose Study, Dr Ramezani Tehrani and her colleagues were able to measure the concentrations of a hormone that is produced by cells in women’s ovaries – anti-Mullerian Hormone (AMH). AMH controls the development of follicles in the ovaries, from which oocytes (eggs) develop and it has been suggested that AMH could be used for measuring ovarian function. The researchers took two further blood samples at three yearly intervals, and they also collected information on the women’s socioeconomic background and reproductive history. In addition, the women had physical examinations every three years. The Tehran Lipid and Glucose Study is a prospective study that started in 1998 and is still continuing.

The standard objection to sample size will naturally be brought forth, but if it’s a valid diagnostic I assume it’ll get popular really quickly.

Here are the results:

Dr Ramezani Tehrani was able to use the statistical model to identify AMH levels at different ages that would predict if women were likely to have an early menopause (before the age of 45). She found that, for instance, AMH levels of 4.1 ng/ml or less predicted early menopause in 20-year-olds, AMH levels of 3.3 ng/ml predicted it in 25-year-olds, and AMH levels of 2.4 ng/ml predicted it in 30-year-olds.

In contrast, AMH levels of at least 4.5 ng/ml at the age of 20, 3.8 ngl/ml at 25 and 2.9 ng/ml at 30 all predicted an age at menopause of over 50 years old. The researchers found that the average age at menopause for the women in their study was approximately 52.

Remember this is a presentation at a conference, not a paper. I don’t have much to say about this from a technical perspective. What do I know? But surely this is important from a science-you-can-use perspective.

The essence of pleasure

Filed under: Anthroplogy,Cognitive Psychology,Hedonism,Paul Bloom,Pleasure,Psychology — Razib Khan @ 11:37 am

I highly recommend this discussion between Paul Bloom & Robert Wright. The topic under consideration is the psychology of pleasure, as reviewed in Bloom’s new book How Pleasure Works: The New Science of Why We Like What We Like. You can also find out about Bloom’s ideas in this exchange in Slate. The essentialism examined in Descarte’s Baby is being taken for another spin, though with a more precise focus. The bottom line is that pleasure is often contingent on more than proximate empirical sensory input; it depends on what you perceive to be the essence of the object of pleasure, even its history (or more crassly, its price). This truth may make the calculation project of the utilitarian heirs of Gottfried Leibniz pragmatically impossible.


June 25, 2010

First they came for Dave Weigel

Filed under: Blog,Technology — Razib Khan @ 11:53 am

Dave Weigel of The Washington Post has resigned over his juvenile postings on an e-list. Basically the postings allowed for Weigel’s mask to slip, and showed him to be a vulgar and immature young man in some contexts. That’s no different from many of us in the proper context. The e-list is now defunct because of this information break.

Someone like Dave Weigel, a reporter who has to make a public pretense toward objectivity, and a somewhat public person, is atypical. But I think it’s the tip of the iceberg. People who know me in “real life” know that nothing they say to me will ever show up on this blog; it’s private, and my day to day interactions almost never intersect with the topicality here. If I want to introduce an idea or concept that someone else familiarized me with I will ask if I can do so, and credit them if they request. But that’s the nature of this blog, which draws more upon the scientific literature or reader feedback. Other outlets blur the line between private & public more explicitly, and if you meet someone with such an outlet, watch what you say, watch what you do. I’ve been on private e-lists where people say things that in public that could really compromise them. I’ve even gotten into disputes with people who were taking one stand in public which I knew could be easily undercut if I “exposed” what they’d said in private.

In the short term by breaking down barriers to information flow the internet is going to result in people retrenching to the narrowest and most trusted circles to “let their hair down.” In the long term I think we might have to reconceptualize what we think of as private or public. Soon enough a whole host of data on anyone you meet will be available on demand. And your data will also be available to them.

Katz

Filed under: Blog,Katz — Razib Khan @ 11:19 am

lavender (1)


green

gravel (1)

Daily Data Dump – Friday

Filed under: Blog,Daily Data Dump,data — Razib Khan @ 10:52 am

23andMe research article finally published. Dr. Dan MacArthur offers his take on a new PLoS Genetics paper which was published using 23andMe’s user base. Of course there’s already information coming out of 23andMe’s user community not getting into the academic literature, see this comment below.

Group Solidarity and Survival. For what it’s worth, I think group solidarity was critical for human survival and flourishing. I suspect it was responsible for the secular increase in cranial capacity for most of hominin history.

Adverse drug reactions from psychotropic medicines in the paediatric population: analysis of reports to the Danish Medicines Agency over a decade. This looks like a correlation, so there might be the issue of the type of woman who is prescribed psychotropic medicines being more prone to have children with birth defects for other reasons. But something to think about.

Trust and Prosperity. This issue is not salient unless you move. There is a difference in trust even within the United States; rural Vermont vs. downtown Boston. The explanation for this difference is straightforward, but there are probably more subtle differences between societies. On an individual level I wonder at the aggregate decrement in productivity and energy due to having to “track” very vigilantly whenever you’re in a public place in a low-trust situation or society.

China’s Export Economy Begins Turning Inward. Remember that China’s population is about the same as the whole world in 1850.

What has Rome to do with Nairobi?

Filed under: Empires,History — Razib Khan @ 8:00 am

rule-empires-those-who-built-them-timothy-parsons-hardcover-cover-artThere are very few books which would attempt to connect the experiences of the 1st century British who lived through Roman conquest with the French under the Vichy regime in World War II. The The Rule of Empires: Those Who Built Them, Those Who Endured Them, and Why They Always Fall by Timothy Parsons attempts to do just that. As John Emerson observed the subtitle is obnoxious; all states fall, not just empires. But in the author’s defense usually they are not the ones who decide upon the title, rather the publishers look for sentences which are catchy and can move some units. A grand explanation of why empires fall may appeal to the average reader. A disparate collection of descriptions of the imperial experience, filtered through a prism strongly shaped by 20th century perceptions and models of colonialism, perhaps not.  The latter is what the The Rule of Empires is. The author is a professor of 20th century African social history, and the specter of the European colonialism of the Dark Continent haunts even the chapters on Roman Britain or Umayyad Spain. Though Parsons’ sympathy with the subjugated is obvious he restrains himself enough so that tiresome polemic does not interfere excessively with the collation of fact or the attempt to engage in objective analysis. Unfortunately the project of a grand theory of the rise and fall of empires, or more accurately the colonized experience,  falls short of its goals. I was totally unpersuaded that the fall of Napoleonic Italy, Roman Britain, or British Kenya, were united in any deep way by inevitable social or institutional forces of history which thread together all empires. Though there are many interesting facts on display, it does seem to me that the author falls into a tendency to transform all imperialists into 20th century British, and all subjects into 20th century Kikuyu. The most recent imperial adventures serve as the models, or the skeleton, around which the grand theory is built, and that only distracts from the specific chapters which are rich with specific detail.


Consider the stab at describing and decomposing the British Celtic experience of Roman conquest and colonization. The reality is that we don’t know much about this experience, a reality which the author admits. Even the most gripping narrative nugget, the rebellion of Boudica and the Iceni against the depredations of the Romans, is historically fraught. To add firmness to this section Timothy Parsons engages in supposition and extrapolation. Some of it is rather stretched to the extreme. Like most social historians he cautions against back-projecting modern notions of nationhood to antiquity, but he can’t help but slipping this framework into his dyads of conqueror and conquered. For narrative purposes setting the Romans against the vague and incomprehensible welter of diffuse Celtic tribes and local affinities would be absolutely unreadable, and analytically intractable. And yet there was no singular British nation which was oppressed by a singular Roman nation. Ancient identity was somewhat different than modern identity. Parsons acknowledges this, and then periodically ignores it nonetheless.

More problematically the author makes some elementary errors in classical history which trouble me. He asserts as a theoretical truth that the distinction between conquered and conqueror must be maintained for proper order of empire through the text. One particular passage in the Roman chapter really jumped out at me:

…Caracalla bestowed blanket citizenship on all residents of the empire in A.D. 212. Those who prefer to imagine the Roman Empire as a civilizing force cite this mass enfranchisement as evidence of its benevolence, but it is more likely that Caracalla’s concession was a pragmatic acknowledgement that the boundaries of true subjecthood had blurred to the point where the Roman Empire was actually no longer an imperial institution by strict definition.

…the respectable and military classes of the empire had become so romanized that the distinction between citizen and subject no longer mattered at the elite level. This universal enfranchisement must have tempered the extractive power of the state and may have contributed to the financial crisis that best the later Roman Empire.

First, the evidence for the economic state of the later Empire is confused. Some scholars assert that after the 3rd century chaos the 4th century empire was nearly as robust as that of the 1st and 2nd centuries. In other words, there is no consensus that revenue extraction decline monotonically; the chaos of the 3rd century may have been an interregnum. It seems rather bizarre to assume a priori that blurred boundaries necessarily entailed lower taxation rates. In fact one of the rationales given for the ease of Arab conquest of the Byzantine Near East was that the Arabs imposed lower taxes than the Byzantines. Whether this is correct, the rate of taxation is subject to may variables and I am not convinced that the theoretical presupposition which Parsons holds to is strong enough to take it as a given.

But the bigger issue is that the description of the consequence of Caracalla’s granting of universal citizenship to free men in the Roman Empire totally ignores the conventional starting point: that it was an attempt to increase the Empire’s tax base! Or at least that is the reason given by Cassius Dio in his description of the edict. Whether this was correct or not, any discussion of this act’s impact on revenue should at least make note of this orthodoxy. I have to wonder then if the author was simply not aware of this basic fact.

Obviously to many this discussion may seem a bit pedantic, but The Rule of Empires is a book rich in fact and dense with data, and in many of the other chapters my own base of data was thinner so I would naturally rely on the author. But if such glaring problems of analysis are present in the section on Rome, a period with which I am familiar, I must admit to some caution at accepting the rest of the data at face value.

More abstractly it seems that the biggest failure of Timothy Parson’s framework is its economic ahistoricism. Prior to the industrial revolution the vast majority of humanity experienced life on the Malthusian margin, and the game of empire was a matter of elites stealing from each other’s human cattle. Additionally, if political orders are broken up into smaller units that would introduce multiplicity of function and possibly greater costs to the peasant producer. More plainly Roman conquest may have introduced economies of scale as well as greater peace in the life of the British peasant, who admittedly had little national identity as it was. This is not the story in The Rule of Empires, even though the author admits that there’s very little empirically to go on. With a unified theoretical framework from the 2nd to the 20th century one might presume that the Romans as rapacious alien conquerors with little sympathy for British peasants would increase taxation, but the 2nd century was a world where all elites were rapacious and had little sympathy for peasants, and the economic pie was notably stagnant in its extent.

In contrast Parsons correctly observes that the the European colonization of Africa was a negative sum affair. In an age of real economic productivity growth and demographic transitions, the gains to colonialism were of symbolism, as well as to a small minority of sub-elites whose primary aim was to exploit the natives for profit. A classic instance of socializing the losses of failed expeditions, and privatizing their gains. The density of the later chapters, and their analytical heft, is a sharp contrast with the often platitudinous regurgitations of secondary literature which seem to dominate the sections on antiquity and the medieval period. Timothy Parsons would have benefited from being less ambitious, and simply admitting that his definition of empire makes no sense before 1800.

Nairobi truly does have little to do with Rome.

June 24, 2010

The dismal gods

Filed under: Anthroplogy,Economics,Economics of Religion,Religion — Razib Khan @ 11:51 pm

marketplaceLarry Witham’s Marketplace of the Gods: How Economics Explains Religion is a manifestly ill-timed book. He states that “…around 2006 I began to notice a good deal of hoopla in the book market about economic explanations for just about everything-books that were best sellers.” Marketplace of the Gods was obviously written to capitalize on the prestige of economic explanations, but unfortunately it has come out after the bubble had burst on that market, so to speak. Within the past few years even many economists have come to admit that the power of their discipline’s logic can explain far less than they’d once thought. In fact, it seems a bit much for economics to explain everything when the core competency in financial domains are themselves being challenged. Even in 2008 in The Logic of Life Tim Harford was engaging in a rearguard attempt to prevent behavioral economists such as Dan Ariely from knocking the legs out from under the central thesis of his book. A more accurate subtitle for Marketplace of the Gods would have been “economic explanations of religion.” Not punchy or imperialistic, but true to the content of the text.


These explanations are rooted in a few assumptions derived from conventional economic methodology and applied to religion. Humans are rational, they settle upon strategies which can fulfill their preferences, and their world is characterized by scarcity and opportunity costs. Phenomena are best explained in a reductionist framework which takes a methodologically individualist stance. In other words, what’s in it for the individual, not society. Larry Witham documents the intellectual journeys of two giants in the field, Rodney Stark and Laurence Iannaccone. I have read Iannaccone’s papers, as well as most of Stark’s academically oriented books. There’s a lot of clear and crisp thinking there. Marketplace of the Gods reviews the long history of woolly theorizing about religion which explained everything and so nothing, and served as the ideal seedbed for the invasion of the subject by those wielding sharper tools.

But the supply side model of individuals consuming goods and services from competing religious firms, to translate religious phenomena into economic language, can not explain everything. The author acknowledges this in the text, but falls into traps whereby the theory which he has encountered allows for superficial inferences which are plainly false if one was aware of a richer set of data. Consider this passage:

In traditions that invest more intensely in human religious capital the rentention rate is highest. For example, Hindu, Catholic, and Jewish groups lose the least number of adherents over their lifetimes. In America today, 90 percent of Hindus were reared in that tradition, and the same goes for 89 percent of today’s Catholics and 85 percent of today’s Jews….

This sounds plausible enough, but the explanation that Hindus and Catholics have high retention because they “invest more intensely in human religious capital” is probably wrong. Hindus and Catholics have huge immigrant communities, and come from societies where religious switching is rare or taboo. The majority of American Hindus are immigrants, so they are not integrated into the American marketplace of gods. The Religious Landscape Survey which Witham references makes it obvious that American Hindus are not even particularly religious. Witham assumes they invest more intensely in human religious capital probably because of the 90 percent figure, but theory is misleading him because of the incompleteness of his data base. Similarly, Catholics have been the biggest contributors in the past decade to the irreligious segment of Americans. The last finding is relatively recent, and so may not have been available when Marketplace of the Gods was being written, but it shows the lack of robusticity of the set of inferences which one can generate from these models. New data easily overturns novel inferences on a regular basis.

Obviously there’s some real insight that can come out of the intersection of economics and religion. And Marketplace of the Gods serves as a decent precis of the literature, and its bibliography is well worth perusing. But if you know anything about religion it will be rather clear that the current theoretical contributions of economics in explaining most of the variation in the phenomenon is limited. Religion is a big topic, and a true “explanation” necessarily has to encompass evolution, psychology, history, and, economics.

You have no privacy, deal with it

Filed under: Culture,Facebook,Privacy,Technology — Razib Khan @ 11:36 am

The Washington Post’s blogger-journalist Dave Weigel has a post up where he preemptively apologizes for stuff he posted on an “off-the-record” e-list,. Extracts are going to be published by a gossip site. Journalists are the tip of the iceberg; privacy is fast becoming a total fiction, remember that. We’re slowly drifting toward David Brin’s model of a “transparent society”, but it’s happening so fluidly that people aren’t even noticing. And yet as I have noted before, people are resisting the push to merge all their personas into one. Interesting times.

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