linkfest – 03/05/14

DNA USA*“[A]bout about 4 percent of whites have at least 1 percent or more African ancestry. Although it is a relatively small percentage, the percentage indicates that an individual with at least 1 percent African ancestry had an African ancestor within the last six generations, or in the last 200 years. This data also suggests that individuals with mixed parentage at some point were absorbed into the white population. Looking a little more deeply into the data, Kasia also found that the percentage of whites with hidden African ancestry differed significantly from state-to-state. Southern states with the highest African American populations, tended to have the highest percentages of hidden African ancestry…. Previous published studies estimate that on average African Americans had about 82 percent African ancestry and about 18 percent European ancestry. But in self-identified African Americans in 23andMe’s database, Kasia found the average amount of African ancestry was closer to 73 percent. Kasia found significant differences in state-to-state comparisons. African Americans in the northern and western states have more mixed ancestry than those in the southern states…. On average Latinos had about 70 percent European ancestry, 14 percent Native American ancestry and 6 percent African ancestry. The remaining ancestry is difficult to assign because the DNA is either shared by a number of different populations around the world, or because it’s from understudied populations, such as Native Americans.” – from 23andMe.

Common Variants in the CDH7 Gene are Associated with Major Depressive Disorder in the Han Chinese Population“Recent genome-wide association study also demonstrated that CDH7 was significant associated with bipolar disorder…. Our results support CDH7 to be a risk factor of MDD in the Han Chinese population. However, further studies with more markers and independent samples were suggested to validate our findings.”

Humans May Have Been Stuck on Bering Strait for 10,000 Years“In the new Perspectives article, published today (Feb. 27) in the journal Science, the researchers compile existing data to support the idea, known as the Beringia standstill hypothesis. Among that evidence is genetic data showing that founding populations of Native Americans diverged from their Asian ancestors more than 25,000 years ago. In addition, land in the region of the Bering Strait teemed with grasses to support big game (for food) and woody shrubs to burn in the cold climate, supporting a hard-scrabble existence for ancient people.” – razib is skeptical.

Was skin cancer a selective force for black pigmentation in early hominin evolution?“[D]ata on age-associated cancer incidence and lethality in albinos living at low latitudes in both Africa and Central America support the contention that skin cancer could have provided a potent selective force for the emergence of black skin in early hominins.”

Neanderthal Introgression at Chromosome 3p21.31 Was Under Positive Natural Selection in East Asians“Studies of the Neanderthal and Denisovan genomes demonstrate archaic hominin introgression in Eurasians. Here, we present evidence of Neanderthal introgression within the chromosome 3p21.31 region, occurring with a high frequency in East Asians (ranging from 49.4% to 66.5%) and at a low frequency in Europeans. We also detected a signal of strong positive selection in this region only in East Asians…. [S]uggestive evidence supports latitude-dependent selection, implicating a role of ultraviolet-B.”

Neanderthals challenge the origins of speech“Neanderthals, may well have spoken in languages not dissimilar to the ones we use today…. [I]n terms of mechanical behaviour, the Neanderthal hyoid was basically indistinguishable from our own, strongly suggesting that this key part of the vocal tract was used in the same way. ‘From this research, we can conclude that it’s likely that the origins of speech and language are far, far older than once thought.'” – h/t billare (who is 0.1% neanderthal)!

READ THIS (yes, there *will* be a pop quiz on the material later in the week (~_^) )!: Environmental Hereditarianism“[T]here is little evidence linking most ‘measurable’ aspects of the environment to human physical or behavioral traits…. Most of the solid evidence we do have for environmental impacts come in the forms of things that do physical damage (e.g., maiming limbs or traumatic brain injury) – a category which includes poisons; or are developmental deficits, such as malnutrition. Much of the rest of it (take your pick) is lacking.” – from jayman. – previously: it’s not nature and nurture….

Outliers – from greg cochran.

New evidence confirms link between IQ, brain cortex“Rate of change in the thickness of the brain’s cortex is an important factor associated with a person’s change in IQ, according to a collaborative study by scientists in five countries…. This study is the first to show the association between cortical thickness and development in full scale IQ, and has potentially wide-ranging implications for the pedagogical world and for judicial cases in which the defendant’s IQ score could play a role in determining the severity of the sentence.”

The Germ Theory of Democracy, Dictatorship, and All Your Most Cherished Beliefs“What kind of government do you live under? Who are your sexual partners? How do you treat strangers? All of these questions may mask a more fundamental one: What germs are you warding off?” – h/t jason collins! – but see this previous post: pathogens and consanguinity“the BIG outliers, though, are the arabs and all their middle eastern/north african/south asian muslim buddies. they are the ones throwing off the correlation completely…. these societies are amongst those that have the highest consanguinity rates, and yet some of their pathogen index scores are *very* low.” that part of the world also does not do well when it comes to (liberal) democracy. – see also jayman’s response.

Nicholas Wade Takes on the Regime – jared taylor reviews nicholas wade’s upcoming book on race. – h/t hbd bibliography! – see also this comment from jayman. – and see also Harmful, toxic equalism from the awesome epigone.

The Nature of Race – from karl boetel and john furest. see also here.

12,000 year old prehistoric art shows woman hunting – maybe. kinda/sorta. (not really.) – from adam benton.

Altruism and the Dark Side of Agreeableness“[B]eware of really nice people. If they seem too good to be true, they usually are.” – from staffan.

Forgotten fathers: paternal influences on mammalian sex allocation“A growing body of evidence suggests that the assumption that males produce an unbiased proportion of X- and Y-chromosome-bearing spermatozoa is not always valid with significant between- and even within-individual variation.” – a mechanism for trivers-willard? – h/t lars penke!

Digit Span: the modest little bombshell and What does IQ 70 mean for black and white kids? – from dr. thompson.

The paradox of the Visual Word Form Area“The VWFA functions differently in different human populations. The difference is striking between people who use alphabetical script, where each symbol represents a sound, and those who use logographic script, where each symbol represents an idea. Chinese subjects process their idea-based symbols with assistance from other brain regions, whereas Westerners process their sound-based symbols only in the VWFA.” – from peter frost.

The man who destroyed America’s ego“How a rebel psychologist challenged one of the 20th century’s biggest—and most dangerous—ideas…. Among the most egregious errors they discovered were those in the papers that focused on academic performance. A correlation had been repeatedly found between high self-esteem and good grades. So, the logic went, if you boosted self-esteem you’d also boost grades. But the authors had made one of the most elementary mistakes in science. ‘When they tracked people over time,’ says Baumeister, ‘the grades came first, and then the self-esteem. High self-esteem was a *result* of good grades, not a cause.'” – h/t matthew wygant!

Genetic Influences on Political Ideologies: Twin Analyses of 19 Measures of Political Ideologies from Five Democracies and Genome-Wide Findings from Three Populations“Here we present results from original analyses of a combined sample of over 12,000 twins pairs, ascertained from nine different studies conducted in five democracies, sampled over the course of four decades. We provide evidence that genetic factors play a role in the formation of political ideology, regardless of how ideology is measured, the era, or the population sampled…. We then present results from one of the first genome-wide association studies on political ideology using data from three samples: a 1990 Australian sample involving 6,894 individuals from 3,516 families; a 2008 Australian sample of 1,160 related individuals from 635 families and a 2010 Swedish sample involving 3,334 individuals from 2,607 families. No polymorphisms reached genome-wide significance in the meta-analysis. The combined evidence suggests that political ideology constitutes a fundamental aspect of one’s genetically informed psychological disposition, but as Fisher proposed long ago, genetic influences on complex traits will be composed of thousands of markers of very small effects and it will require extremely large samples to have enough power in order to identify specific polymorphisms related to complex social traits.”

Why Americans Are So Polarized: Education and Evolution“Improvements in learning — which correlates with stronger partisanship — and the tendency to choose likeminded mates may be helping to create divided politics.” – from avi tuschman. – h/t eddy elmer!

Conservatives generally more willing to take business risks, study finds

Paternal Age at Childbearing and Offspring Psychiatric and Academic Morbidity“In the study population, advancing paternal age was associated with increased risk of some psychiatric disorders (eg, autism, psychosis, and bipolar disorders) but decreased risk of the other indexes of morbidity.”

A Genotype-First Approach to Defining the Subtypes of a Complex Disease – h/t kevin mitchell who tweeted: “Increasing recog’n that ‘common disorders; like autism really umbrella terms for many rare diseases.”

Researchers look at boy-girl differences in autism“Boys, it seems, can develop autism from a relatively small genetic hit, according to a study published today in the American Journal of Human Genetics. It takes more of a genetic wallop, though, to cause autism in girls – so when they do get it, they’re worse off. The same explanation holds true, researchers think, for the gender imbalance in ADHD (attention-deficit hyperactivity disorder), intellectual disabilities and schizophrenia.” – see also: A Higher Mutational Burden in Females Supports a “Female Protective Model” in Neurodevelopmental Disorders.

China Cracks Down on DNA Testing – h/t jayman!

Epigenetics: The sins of the father – big story in nature today. – “The roots of inheritance may extend beyond the genome, but the mechanisms remain a puzzle.” – but swedish scientist on twitter says: “But Rando misquotes Swedish human data in his Cell paper on mice. Caution for epigenetic hype!” – hmmmm. =/

The Consequences of Natural Morality“Good and Evil are not objective things. They exist as subjective impressions, creating a powerful illusion that they are objective things. This illusion that Good and Evil are objects independent of the conscious minds that imagine them exists for a good reason. It ‘works.’ In other words, its existence has enhanced the probability that the genes responsible for its existence will survive and reproduce.” – from helian.

Digit ratio predicts eminence of Polish actors – this one’s for sisyphean! (^_^) – h/t ben southwood!

Sex differences in color preferences transcend extreme differences in culture and ecology.

In Academia, Women Collaborate Less With Their Same-Sex Juniors“‘Some older women treated us younger women almost worse than some men did,’ she says. ‘We called it the “Queen Bee syndrome.”‘” – heh. – h/t claire lehmann!

Women Can Keep the Vote: No Evidence That Hormonal Changes During the Menstrual Cycle Impact Political and Religious Beliefs – behind paywall.

Women ‘subconsciously outdo other females’ during ovulation“But what the researchers found really surprising is that ovulating women did not appear to want a higher standing over men – they became kinder to them. When playing the dictator game, non-ovulating women shared 45% of their money with men, while ovulating women were willing to share 60% of their money with men. These findings are unlike anything we have ever seen in the dictator game. You just don’t see people giving away more than half of their money,’ says Prof. Durante.” – (~_^)

Women Outperform Men in Ultra-Distance Swimming – The ‘Manhattan Island Marathon Swim’ From 1983 to 2013. – because we float better (because we have that extra layer of fat)? (~_^)

Sameness and the self: philosophical and psychological considerations.“[H]ow can a person maintain a belief in the sameness of self over time in the face of continual psychological and physical change?” – h/t neuroskeptic!

Young Children Can Be Taught Basic Natural Selection Using a Picture-Storybook Intervention – but not politically correct people, apparently. (~_^) – h/t stuart ritchie!

Study: Racial bias in pain perception appears among children as young as 7 – see also: Psychologists use baby-cam to study infants’ exposure to faces.

Mixed-race children ‘are being failed’ in treatment of mental health problems“Children of mixed race are at greater risk of suffering from mental health problems and are not getting the support they need, says a report.” – in the u.k.

Inferring Character From Faces: A Developmental Study.“This research suggests that the predisposition to judge others using scant facial information appears in adultlike forms early in childhood and does not require prolonged social experience.”

Los europeos no inventaron la desigualdad en Hispanoamérica – from eduardo zugasti.

Native American city on the Mississippi was America’s first ‘melting pot’carcosa cahokia. – “By analyzing the teeth of those buried in different locations in Cahokia, Emerson, state archaeological survey bioarchaeologist Kristin Hedman and graduate student Philip Slater discovered that immigrants formed one-third of the population of the city throughout its history (from about AD 1050 through the early 1300s).”

Two-hundred-year drought doomed Indus Valley Civilization“Monsoon hiatus that began 4,200 years ago parallels dry spell that led civilizations to collapse in other regions.”

HBD 101 – from malcolm pollack. (*^_^*)

bonus: A ‘Second Great Wave’ of immigration?“‘Once again, the country is approaching a percentage of foreign-born not seen since the late 1800s and early 1900s,’ the Census Bureau wrote on its blog this week.” – =/ – h/t ray sawhill!

bonus bonus: Muhammad’s birthplace to be razed – remember that the najdis hate the hejazis and vice versa.

bonus bonus bonus: Giant Virus, Awakened From 30,000-Year Slumber, Is Still Infectious – ruh roh (if you’re an amoeba)!

bonus bonus bonus bonus: Crawling Through The Brain Without Getting Lost“Do the wasps taste their way through a cockroach brain?” – mmmmmm! =/

bonus bonus bonus bonus bonus: Australia: Snake eats crocodile after battle – WITH PICTURES! =o – h/t ed west!

(note: comments do not require an email. g-8 selfie. (~_^) )


hejazis vs. najdis (and vice versa)

in my last post on saudi arabs, i mentioned that there are maybe, perhaps some hints that the historic mating patterns amongst the najdis of the central part of the arab peninsula were closer than those amongst the hejazis of the western coast. maybe. there are only hints, so it’s hard to be sure.

one other hint that the hejazis maybe outbred a bit more than the najdis is the somewhat greater freedoms that women have historically had in the region (the pattern seems to be the stronger the inbreeding, the more restrictions on women). from Cradle of Islam: The Hijaz and the Quest for an Arabian Identity [pg. 27]:

“As in other societies the Arab concept of family is closely linked to that of female honour. In the Arabian Peninsula the urban Hijazis have historically been viewed as more lax or lenient in such matters than tribal Najdi culture, with its strict Wahhabi norms of sexual segregation. An increased emphasis on female honour has, however, developed among some of the Hijazi *’awa’il* in reaction to Najdi standards.”

if the elevation/marginal environment theory of inbreeding/outbreeding is correct, then it would make sense if arabs living right along the coast in the west were inbred less. same for those on the east coast, i suppose. (the greatest oubreeders of the arab peninsula ought to be in the southeast area of saudi arabia, but i don’t think many people live there!):

saudi arabia - topography

in any case, saudi society is not just clannish, it’s downright tribalistic — and the people of the hejazi region don’t like the people of the najdi region. and the feeling is very much mutual [pgs. 16-17, 85]:

The most obvious and important expression of the persistence of social boundaries is the rarity of intermarriage between Najdis and Hijazis, with obvious implications for cultural assimilation. Hijazi opinion on this matter varies. Some explain that Najdi men fear the consequences of marital alliances with Hijazi families, while others contend that Hijazis are reluctant to allow their daughters to marry Najdis, because of polygamy, ease of divorce and stricter gender segregation among the Najdis. Najdi men — who do not hesitate to take wives from other Arab countries — regard marrying a woman from the same country as a greater commitment, especially when she is from an inferior or less ‘pure’ lineage in the Najdi grading of tribal descent. Meanwhile, the Hijazies, who claim descent from the Prophet’s tribe, the Quarysh, consider themselves the superior ones. Competition in ‘purity of blood’ in the Arabian Peninsula reaches its apotheosis in the context of intermarriage, and the few instances of it are typically between a Hijazi man and a non-tribal (i.e. ‘non-pure blood’) Najdi *khadiri*, as a tribal Najdi *gabili* will not marry outside the group. Even in these rare cases, the Najdi *khadiri* family typically makes the marriage procedures very lenthy and costly….

“The images that Hijazi and Najdi have of one another and the names they use to describe each other are further indications of social boundaries and the consciousness that sustains them. The Hijazis, for example, call the Najdis *shurug* (Easterners), a derogatory term. Another term, *badu* (Bedouin), carries an even worse connotation — essentially a lack of urban refinement. On the other hand, the Najdis call Hijazis *tarsh al-bahr*, (the flotsam of the sea) and *bagaya hujjaj*, (pilgrimage remnants). Whereas the first term is applied to those from Jeddah and the second to Meccans and Medinese, both allude to the ‘impurity’ of Hijazis’ Arab descent, owing to intermarriage with non-Arab Muslims. While the Najdis pride themselves on their lineage and *asala* (purity of blood), the Hijazis pride themselves on their *zawg* (good taste), *anaga* (elegance), *nazaka* (refinement) and *usul* (knowledge of the rules of propriety). To be sure, Hijazis also place lineage as the first criterion of status and respectability, especially those claiming descent from the Quraysh. But for those from other Muslim countries who settled in Mecca, Medina or Taif, lineage does not imply ‘blood purity’, but rather three generations of good social standing. As a result, ‘Najdis regard Hijazis as degenerate and not quite Arabian’….

“Marriages between Hijazis and Najdis are very rare. The exceptions are one way, occurring between a *khadiri* (non-tribal, ‘non-pure’ Najdi) woman and a Hijazi man, especially if he is wealthy and offering a high *mahr*. Najdis do not marry Hijazis because their lineage is not considered pure enough. Therefore Hijazis are excluded from marriage with the Najdi elite…. The rarity of cases of inter-marriage between Hijazis and Najdis is the most significant expression of the social boundaries between the regions of Saudi Arabia and an obvious example of the cultural distinctivenss of the Hijazis. Despite the attempt at integration and national homogeneity, marriage practices and alliances demonstrate the fractured nature of the Saudi state.

not much love there, then.

and, like i said, saudi society is very tribal — extremely tribal. from Challenges to the Cohesion of the Arab State [pgs. 181-182, 184, 186-187 – links added by me]:

“Saudi Arabia is known in the literature as a ‘rentier state.’ In its most narrow meaning, a rentier states refers to a state which gains most of its revenues not from taxes, but rather from the income (‘rents’) derived from the sale of natural resources, in this case — petroleum. In the Saudi case, the state distributes much of the income to the population, without taxing it. Saudi Arabia has (as have other wealthy Gulf states) an unwritten ‘social contract’ between the Sa’ud family and its subjects: the family runs a cradle-to-grave social welfare system and guarantees employment in the public sector; in exchange, the population is expected to be loyal, without having a representative system. It is, in fact, a system of ‘no taxation, no representation.’

This governmental system dovetails quite nicely with the tribalistic character of Saudi Arabia, and to a great extent even duplicates it. Although the tribe, as a discrete social unit, has been somewhat weakened in Saudi Arabia due to the efforts of the Saudi state, the structure of relations between the Sa’ud family and the population operates to a great extent according to tribalistic patterns and values, and thus contributes to national cohesion.

“Certain political, and socio-economic groups develop a corporate identity and behavior, not unlike that of tribes. These groups are termed *’asabiyyat* (from the word *’asabiyya*, tribal solidarity), and indeed form the core of social cohesion in Saudi Arabia. They are patron-client groups that have a common tribal, regional, family, or ethnic background, which is used to obtain jobs or resources from the central government. In return, the central government uses these relationships to command the loyalty of these groups. In this sense, the state is an extension of tribal politics.

in 1961, when the saudi central government was moved from jeddah (in hejazi territory) to riyadh (in najdi territory), pretty much ALL of the hejazi civil servants were sacked and replaced with najdis [pg. 94]. now THAT’S what i call nepotism!

more from Challenges to the Cohesion of the Arab State:

“Tribalistic patterns of behavior are characterized by a high degree of personalization since they are based on personal relationships. For instance, the main ministries are headed by members of the Saudi royal family that represent the various ‘circles of power.’ To get a job in one of those ministries, one must ally oneself with the relevant faction of the family, or with someone associated with it. The most powerful circles of power [in 2008 when this book was published-h.chick] are the Al Salman (connected to Salman, the governor of Riyadh province), the Al’ Abdallah (associated with the present king), the Al Fahd (connected to Fahd, who was king until his death in 2005), the Al Na’if (connected to the minister of the interior, and the Al Sultan (connected to the heir apparent and minister of defense and aviation). These circles act as corporate groups looking out for one another. They consist of blood relatives and their associates. Until a few years ago, applicants for government jobs were required to provide their family and tribal background, going back five generations, as part of the application process. This clearly illustrates how the royal family uses tribal patterns and values to maintain its rule.

“Like the head of a tribe, the state is responsbile for the protection of its citizens. The state, personified in the Sa’ud family which functions as the head of a tribe, protects the people’s physical and financial safety. Like all tribal leaders, members of the royal family mediate disputes, and keep the peace….

The Saudi royal family/state also functions as a genealogical organizer of society. As tribes did in the past, it determines who will marry whom. The fact that it makes it hard for Saudis to marry non-Saudis contributes to the myth of an entire country under Sa’ud domination, of one vast exclusive tribal family patronized by the Al Sa’ud. Since Saudi citizenship, which grants admission to the tribal family, confers entitlement to the largesse of the *shaykh*, the Saudis have created powerful incentives for their citizens to accept the truth of the myth of Saudi national identity, an identity fused with religion, in which membership is in fact a coveted privilege bestowed by birthright….

“Regional identities

“The region with the most highly developed sense of regional identity is the Hijaz, a strip of land along Saudi Arabia’s Red Sea coast, stretching from the border with Jordan in the north nearly to Yemen in the south. In it are situated the two holiest places in Islam, Mecca and Medina.

“In the Hijaz the elite are quite aware of the status they enjoyed before what the Saudis call unification, and some Hijazis call occupation, or annexation. When they feel they are being treated as second-class citizens, which they often are because the Najdis hold most of the government and religious jobs, they strive to gain recognition by asserting their distinctiveness as the elite of Islam’s holiest places.

“One recent manifestation of the this regionalism is the periodical *al-Hijaz*, published in London by the Hijazi National Organization (*al-jam’iyya al-wataniyya al-Hijaziyya*). The periodical is extremely anti-Saudi, and seeks to celebrate Hijazi culture and distinctiveness. The articles, most of which remain unsigned, refer not to the ‘unification’ of Arabia under the Saudis, as stated in the official narrative, but rather to the occupation of the Hijaz….

“Some Hijazis are thus beginning to assert their distinctiveness, whether through writing about Hijazi customs and food, or by wearing Hijazi dress. Indeed, there seems to be a revival of Hijazi dress lately. People who choose to wear Hijazi dress do so at some risk since it is Najdi dress which is considered the national dress and is worn by most of those in or close to power. What one wears is a statement, and is noted immediately. Some Hijazis are demonstratively reverting to their own regional dress, which includes a tighter-fitting robe calle a *jubba*, and a turban, or *’amama*….

“One man stands out as leader of the Hijazi cultural movement, namely Sami al-Angawi, an architect, who has made it his life’s work to preserve the customs, dress, and architecture of the Hijaz against Najdi attempts to eliminate them. He openly wears Hijazi dress. Moreover, he explicitly declares that he is a Sufi, a mystic — in other words, that he belongs to a stream of Islam which is forbidden by the Wahhabi clerics, who monopolize religion in Saudi Arabia.

He has protested the destruction of Hijazi architecture and Hijazi holy sites by envious Wahhabis, who see the worship of these sites as unlawful religious innovation (*bid’a*). Several of these sites have been destroyed, the most recent amongst them being the Jiyad fortress, built by the Ottomans in the eighteenth century, and destroyed in 2002. The fortress was the site from which Husayn bin ‘Ali started the Arab Revolt in Mecca. It overlooks the Ka’aba, and was removed to make way for a massive, five-story project. The developers of the project are the Bin Ladin Company, which has close ties to the royal family.”

i could never understand all the destruction of islamic sites — including mohammed’s mother’s grave (!) — happening in mecca and medina (see also here). greed (i.e. wanting to build huMONgous hotel complexes to milk the hajj crowds) doesn’t seem to cover it, afaiac. but now that i know that all these sites are in hejazi territory and are connected with hejazi history — and the fact that it’s mostly najdis destroying them — NOW it all makes sense! it’s tribes vs. tribes, that’s all.

previously: historic mating patterns on the arabian peninsula and tribalism on the innerwebs

(note: comments do not require an email. mecca’s big ben!)

historic mating patterns on the arabian peninsula

anybody else getting a little bored with europe and europeans? yeah, i thought so. here’s a little diversion! (i will return to the mating patterns of europeans shortly.)

the arabs. and by “the arabs” i mean the ones on the arabian peninsula. even more specifically, i mean to contrast the arabs living in the hejaz on the west coast with the arabs from the najd in the interior. for a very long time, the hejazi arabs have been quite comopolitan and internationally-oriented, whereas the najdi arabs were mostly camel-herding nomads or settled in and around desert oases. the balance of power between the two shifted beginning in the 1700-1800s when the al saud clan — from the najd region — gained control of the region, and, most importantly, when they eventually acquired de facto control of the nation’s oil. tells us that the saudi arabians today inbreed a LOT: 50%+ of all marriages are consanguineous (between second cousins or closer). there is variation within the country though.

from Consanguinity among the Saudi Arabian population (1995) [click on table for LARGER view] …

consanguinity among the saudi arabian peninsula - table 02

… the total consanguinity rate in what the authors refer to as the “north western province” (i think this must be some former provincial designation), which is basically the hejaz region, was 67.7% in 1995. the “central province” — the northern part of the najd region — had a consanguineous marriage rate of 60.8% — so lower than the hejaz region.

i don’t think that this was always the case, that consanguineous marriage was more common in the hejaz region than in the najd region. in fact, i think that the hejazis have adopted cousin marriage more and more over the course of the last couple of centuries thanks to a process of “najdification” that, presumably, the entire country has been undergoing since the al saud clan came to prominence. (also, perhaps many najdis have moved to places in the hejaz region like mecca.)

from Cradle of Islam: The Hijaz and the Quest for an Arabian Identity (2004) [pgs. 77-81]:

Of key interest here is the introduction of what may be called the ‘tribalisation’ of marriage relations amongst the Hijazis. In contrast to past practices of marriage with non-Arab Muslims, marriages now take place within the Hijazi cultural group. The definition of what constitutes a Hijazi for marriage purposes has become more strict….

One implication of ‘tribalisation’, however, is that it draws the cultural form of association that sets the standards for the Hijazis from Najdi life. The emphasis placed on lineage, purity and related ideas confirms the superiority of a particular conception of what a social group should be: a tribe….

“For members of the Hijazi *’awa’il*, establishing and dissolving contemporary marriage relationships is now regulated by several sets of rules and considerations, most of which are relatively recent in origin…. All of these changes are best understood in light of the contrast between the period prior to and that following the Hijaz’s political unification under Saudi rule….

“In the period before Saudi political unification the rules governing marriage derived from largely religious sources, reflecting a very different relation between state and society to that which exists in the present. All contemporary marriage rules are closely related to these earlier ones, either as refinements or entailing new but subordinate principles.

“At the most general level, the Quran is broadly permissive of potential marriage partners: ‘Oh! Mankind! We have created you from a single [pair] of a male and a female, and made you into nations and tribes, that ye may know each other. Verily the most honoured of you in the sight of Allah is the most pious of you.’ There are, however, some qualifications to this open-ended approach. The first is that Islam permits marital ties between Muslim men and non-Muslim women, provided the latter are ‘people of the book’, *ahl al kitab*, i.e. Jews or Christians. The Quran tells male Muslims that, ‘lawful for you are the chaste women from among those who have been given the book’. Muslim women, on the other hand, are absolutely prohibited from marrying non-Muslims. A Muslim woman’s marriage to a non-Muslim is considered to entail illegal intercourse and thus produces illegitimate offspring who are prohibited from inheriting the father’s wealth….

“In addition to religion, considerations of the nature of wider family life have been most influential in regulating marriage. Here the promotion and defence of patrilineal group status is of central significance. Family status is related to the *’ird* (honour) of its male members, which is defended by ensuring the chastity of female dependants. The idea of *’ird* is a key reason why marriage based on overt love has traditionally been considered *’ayb* (shameful): admitting love implies a clandestine pre-marital relationship. Indeed, the idea that marriage should be based on an emotional bond between husband and wife conflicts with the primacy of maintaining well-integrated families; it implies putting one’s personal interests and needs above the extended family’s wellbeing. In this, Hijazis conform to general Arabian attitudes but, as ever, the Hijazi preoccupation with family creates a specific distrust of bonds based on emotion or sentiment….

Accounts of the late nineteenth and early twentieth centuries clearly show that these rules did indeed regulate Hijazi marriages. For instance, being Muslim, regardless of other origins, provided a sufficiently strong basis on which to build marriages. Mecca was a melting pot for the Islamic world, so mixed marriages were common. Marriage made a significant contribution to the heterogeneous and cosmopolitan nature of Hijazi society.

By contrast, Najdi marriage was, and remains within the same lineage, with bonds among the tribal families usually reinforced by patrilineal parallel-cousin marriages. There is, however, an important distinction between *khadiri* (non-tribal, i.e. ‘non-pure’ Najdi), and *gabili* (tribal ‘pure-blooded’ Najdi). Strict patrilinearity allowed *gabili* men to marry outsiders, such as Egyptian, Moroccan or Lebanese women, but their female relatives have never married outside the tribe. In principle, then, men from the Hijaz would not have been able to marry into a pure-blooded Najdi family, while women would, although Hijazi women were not, as a rule, given in marriage to Najdi families, nor were they asked. In this intricate system of social boundaries expressed through marriage practices, Hijazis — both men and women — married from the Asir tribal region more easily than from the tribal Najd….

“Among elite Najdi men polygamy has also been more prominent.”

so it sounds as though the najdi arabs have had a longer history of closer inbreeding than the hejazi arabs.

if we go even further back, there are more hints that the hejazis may have been comparative outbreeders, as far as arabs go anyway. from Close Relationships: Incest and Inbreeding in Classical Arabic Literature (2005) [pgs. 78-81]:

“Much has been written on the extent to which Islam changed or confirmed the existing customs in pre-Islamic Arabia. Data on these customs are scanty…. As for the forbidden degrees of marriage, early Muslim authorities explain that the main differences between pre-Islamic and Islamic customs concerned the marriage of stepmothers and sons, and being married to two sisters simultaneously. Muhammad ibn al-Saib al-Kalbi (d.146/763) praises the Arabs in the Jahiliyya, the period of ‘ignorance’, for anticipating the Qur’anic prohibitions:

“‘The Arabs, in the time of their Ignorance, held things for forbidden that the Qur’an was to declare forbidden. They did not marry daughters or mothers, nor sisters or aunts from the mother’s side or the father’s side. The worst thing they used to do was to be married to two sisters at the same time, or to succeed one’s deceased father as husband to his wife. They used to call someone who did this *dayzan*….

“‘(…) If a man died, leaving a wife, or divorced his wife, his eldest son would stand up and throw his cloak over her if he wanted her. If he did not want her, one of his brothers would marry her, with a new brideprice.’

“Ibn Habib (d. 245/860), who has a nearly identical passage, adds that ‘Islam has separated men from the wives of their fathers; they are numerous’….

“Ibn Habib also states that the Arabs used to marry two sisters….”

not too much about marrying cousins there, but there’s this…

Against the tendency of presenting the pre-Islamic Arabs as being very close to Islam already, others restrict this virtuous behaviour to the inhabitants of Mecca, contrasting them with the Bedouins, as did Yaqut in the passage quoted above….

and that passage from yaqut [pg. 60]:

“In his ‘Kitab al-Arab’ (‘Book of the Arabs’), devoted to the virtues of the Arabs, Ibn Qutayba praises especially Quaysh, the Prophet’s tribe, for preserving something of the old Abrahamic religion, inherited through Abraham/Ibrahim’s son Ismael/Imail; these remnants included ‘circucision, ritual ablution, repudiation of women, manumission of slaves, and the prohibition of marriage with forbidden family members, through kinship, milk relationship, or affinity by marriage’. Yaqut (d. 626/1229) rephrases the same idea: the pre-Islamic Meccans:

‘were not like the uncouth Bedouins. They used to circumcise their sons, to perform the Hajj at the Kaaba; … they shunned marriages with a daughter, a daughter’s daughter, a sister, and a sister’s daughter, because of their sense of jealous honour and in order to keep aloof from the Magians.'”

in other words, perhaps the pre-islamic hejazi were not at all like the pre-islamic najdis (bedouins) … and, perhaps, the hejazi — the population from whence mohammed hailed — didn’t inbreed so much [pg. 81]:

In general, as far as may be ascertained, inbreeding was not very common in pre-Islamic times. It is difficult to obtain precise information. The genealogies of tribes and clans in the pre-Islamic and early Islamic periods, though very detailed, are notoriously unreliable, loaded as they are with politics and sentiments; an alliance between tribes was often cemented by fabricating a common ancestor. Moreover, the genealogies normally present the male lines only and give very little information on females. Among the exceptions are the lineages of the Prophet Muhammad and other prominent early Muslims. Thus Ibn Habib gives Muhammad’s ancestors in the all-female line, going back seven generations. Similar but shorter matrilinear lines are given for Abu Bakr, Umar, Uthman, Ali, and al-Hasan. Only two lines are given in full in these lineages: the all-male and the all-female, out of the theoretical maximum of 128 (2 to the 7th) lines of ascendants that go with a full picture of seven generations in Muhammad’s case. Therefore it is hazardous to draw any firm conclusions. Yet the general picture that emerges from this admittedly limited sample is clear: there may have been ‘irregularities’ by Islamic standards, such as the above-mentioned stepmother-marriages, but the spouses are not closely related and even first-cousin unions, often assumed to be dominant in Arab society, are almost absent as far as can be observed. In the Prophet’s lineage, one finds that his great-grandmother Umm Habib and her husband Abd al-Uzza had a great-grandfather (Qusayy) in common; Uthman’s maternal great-great-grandmother Sakhra bint Abd ibn Imran married her first cousin Amr ibn Aidh ibn Imran.”

perhaps mohammed — who invented a fairly (fairly) universalistic religion — came from a comparatively not-so-inbred population [i.e. the hejazi arabs – mohammed’s tribe, the quraysh tribe, was from mecca]. -?- dunno. difficult to tell, but it’s an interesting question, i think.

previously: inbreeding and the ancient hebrews (and the arabs) and father’s brother’s daughter’s marriage

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