Archives for posts with tag: inbreeding

a linkfest! (^_^) ’cause i hate linkfasts, too. (*^_^*)

Whole genome sequence analyses of Western Central African Pygmy hunter-gatherers reveal a complex demographic history and identify candidate genes under positive natural selection“African Pygmies practicing a mobile hunter-gatherer lifestyle are phenotypically and genetically diverged from other anatomically modern humans, and they likely experienced strong selective pressures due to their unique lifestyle in the Central African rainforest…. Our two best-fit models both suggest ancient divergence between the ancestors of the farmers and Pygmies, 90,000 or 150,000 years ago. We also find that bi-directional asymmetric gene-flow is statistically better supported than a single pulse of unidirectional gene flow from farmers to Pygmies, as previously suggested…. We found that genes and gene sets involved in muscle development, bone synthesis, immunity, reproduction, cell signaling and development, and energy metabolism are likely to be targets of positive natural selection in Western African Pygmies or their recent ancestors.”

Directional dominance on stature and cognition in diverse human populations“[I]ncreased homozygosity was associated with decreased trait value, equivalent to the offspring of first cousins being 1.2 cm shorter and having 10 months’ less education. Similar effect sizes were found across four continental groups and populations with different degrees of genome-wide homozygosity, providing evidence that homozygosity, rather than confounding, directly contributes to phenotypic variance. Contrary to earlier reports in substantially smaller samples5, 6, no evidence was seen of an influence of genome-wide homozygosity on blood pressure and low density lipoprotein cholesterol, or ten other cardio-metabolic traits. Since directional dominance is predicted for traits under directional evolutionary selection7, this study provides evidence that increased stature and cognitive function have been positively selected in human evolution, whereas many important risk factors for late-onset complex diseases may not have been.” – see also Not tonight, cousin from dr. james thompson. and see also Inbreeding from greg cochran. and see also Directional dominance on stature and cognition from steve hsu.

Genes Unite Executive Functions in Childhood [pdf] – h/t brian boutwell! who tweeted: “Shared genes explain all of the covariance in exec functioning items. No parenting effects to be found.”

200 Blog Posts – Everything You Need to Know (To Start) and The Rise of Universalism and Demography is Destiny, American Nations Edition and National Prosperity – jayman’s been on a roll lately! (^_^) each of these warrants your close attention!

Heritability and the evolution of cognitive traits

CNVs in neuropsychiatric disorders“Over the last few years at least 11 copy number variations (CNVs) have been shown convincingly to increase risk to developing schizophrenia: deletions at 1q21.1, NRXN1, 3q29, 15q11.2, 15q13.3 and 22q11.2, and duplications at 1q21.1, 7q11.23, 15q11.2-q13.1, 16p13.1 and proximal 16p11.2. They are very rare, found cumulatively in 2.4% of patients with schizophrenia and in only 0.5% of controls. They all increase risk for other neurodevelopmental disorders, such as developmental delay and autism spectrum disorders, where they are found at higher rates (3.3%). Their involvement in bipolar affective disorder is much less prominent. All of them affect multiple genes (apart from NRXN1) and cause substantial increases in risk to develop schizophrenia (odds ratios of 2 to over 50). Their penetrance for any neurodevelopmental disorder is high, from ∼10% to nearly 100%. Carriers of these CNVs display cognitive deficits, even when free of neuropsychiatric disorders.”

Improving Phenotypic Prediction by Combining Genetic and Epigenetic Associations [pdf] – h/t dr. xaverius!

County level homicide rates by race/ethnicity of victim and On the effects of wealth on the B-W gaps, a response to questions posed by a commenter @random critical analysis.

the much discussed post The IQ Gap Is No Longer a Black and White Issue – from chanda chisala. see also Chanda Chisala: An African Hereditarian?“If evolution applies to all of us, that includes Africans. It is perfectly possible that some African sub-groups are brighter than others. Any geographic group which takes care to encourage bright persons to marry one another could see positive effects after 20-30 generations of consistently strong selection, if those brighter parents have more surviving offspring, which is likely.” – from dr. james thompson. and see also The Jews of West Africa? from peter frost. and see also my post: there’s more to human biodiversity than just racial differences.

The Water-Crossers – from greg cochran.

Ancestry Matters: Patrilineage Growth and Extinction – h/t ben southwood! who tweeted: “Higher status Chinese patrilineages in the 18th and 19th centuries had more ancestors for hundreds of years after.”

The puzzle of European hair, eye, and skin color – from peter frost.

The people who need very little sleep

How evolutionary psychology may explain the difference between male and female serial killers“[R]esearch has shown that male serial killers tend to stalk and kill strangers. But FSKs tend to kill people they know. It seems, then, that MSKs are hunters and FSKs are gatherers.”

Is the Romantic–Sexual Kiss a Near Human Universal – apparently not! – “The romantic–sexual kiss was present in a minority of cultures sampled (46%). Moreover, there is a strong correlation between the frequency of the romantic–sexual kiss and a society’s relative social complexity: the more socially complex the culture, the higher frequency of romantic–sexual kissing.”

Men are both dumber and smarter than women – just an ok article, but interesting to see this out there *at all*.

Historical Artifacts of the Blank Slate – from helian.

On a Fast Track – Can rapid genome sequencing at birth help save lives?

Genomics Industry Generating Huge Amounts Of Data Due To DNA Sequencing – yay!

Ageing rates vary widely, says study“A study of people born within a year of each other has uncovered a huge gulf in the speed at which their bodies age…. [S]ome people had almost stopped ageing during the period of the study, while others were gaining nearly three years of biological age for every twelve months that passed.” – original research article: Quantification of biological aging in young adults.

Reacting to Spree Killings, Progressively – @thosewhocansee.

for you brits: Is that stranger opposite you a distant cousin?

bonus: Pluto’s discoverer’s ashes will be the first human remains to leave the solar system — glued to the side of a space probe – *sniff*

bonus bonus: r.i.p. conrad – *sniff*

bonus bonus bonus: tweet of the week! (~_^) >>

(note: comments do not require an email. r.i.p. conrad. *sniff*)

further to the point of when did the arabs start marrying their fathers’ brothers’ daughters (fbd marriage), from kudelin (2005) – “Family-Matrimonal Relations in the 5th-7th Centuries Arabia and Their Reflection in the Early Arabic Poetry” [pgs. 8-9]:

“According to one point of view, in the 5th-7th century Arabia there was a decay of the communal-clan system which was reflected, in particular, in the ‘tendency towards isolation of a consanguine group by regulating family and matrimonial relations’ with the transformation of such group from an exogamic into an endogamous one. At that period the exogamic form of marriage was gradually losing its ‘oneness and ubiquity’ and edogamy was becoming firmly established. Obviously, during some period of time both forms of marriage coexisted simultaneously….

“Consistent introduction of paternal relations and the distribution of endogamy lead to such well-known form of matrimonial relations as [fbd] marriage which prevailed on the Arabic Peninsula from the 6th-7th century. In the conditions of the growing role of endogamy in this period the most suitable spouses in the Arabic society were ‘a son of an uncle on the father’s side’ (*ibn ‘amm*) and ‘a daughter of an uncle on the father’s side (*bint ‘amm*). If a girl did not have a first cousin, the right to marry her passed to the patrilineal cousins of further degrees. Usually the right did not pass further than the girl’s cousins of the third or fourth degrees…. In case of divorce, the right for the woman passed to other patrilineal cousins, beginning from the closest degree of kinship. An agnatic cousin had the right not to marry his relative, while she could not marry anyone else without his consent. An exterior competitor had to ask a patrilineal cousin for his permission and even pay him ‘compensation’….

“The coexistence of the exogamic and the endogamous forms of marriage in the 5th-7th century Arabia was reflected in the early Arabic poetry and determined its uniqueness.”

so it looks as though that, thanks to a quirky twist of history (the fall of the roman empire, perhaps?), the arabs adopted the form of cousin marriage that leads to the most inbreeding (fbd marriage) at just around the same time that europeans (especially northwest europeans) began to abandon cousin marriage altogether. how’s THAT for a clash of civilizations?!

there should be more on this here in robertson smith’s Kinship and Marriage in Early Arabia, which i haven’t looked at yet.

around three or four hundred years after europeans started taking the medieval church’s cousin marriage bans seriously (ca. the 800s judging by the franks — ymmv), european languages shifted to reflect this change in mating patterns. a general term for “cousins” (and aunts and uncles) became the norm, replacing the older terms which specified “mother’s brother’s daughter” or whatever. it was no longer necessary to distinguish the “bint ‘amm” (father’s brother’s daughter in arabic) or “biǎo” cousins (cousins other than those descended from the father’s brother in chinese [mandarin?]) because all cousins were now off limits as far as marriage was concerned. this linguistic shift occurred between the twelfth and fifteenth centuries in german and also happened in english, french, etc. (interestingly, a similar linguistic shift happened in ancient greek, indicating…?)

the funny thing is, though, that the same linguistic shift also happened in italian, even though plenty of (especially southern) italians kept right on marrying their cousins — up until, like, yesterday. well, now i’ve stumbled across some historic regional differences in kinship terminology in italy. from “Land, Kinship, and Consanguineous Marriage in Italy From the Seventeenth To the Nineteenth Centuries” [pgs. 532-533]:

“In a rural town of Calabria in the province of Catanzaro, patrilateral parallel cousins were called *cugini giusti* (right cousins), or *surrea* and *frateu* in the case of the patrilateral parallel female and male cousins, respectively….

“At Prodo, in Umbria, we find virtually the same terminology as in Calabria. The strongest bond was between the males; patrilateral parallel cousins were called ‘brother-cousins,’ while others were simply called cousins….

“In Desulo, first cousins through brothers were known as *karrales*, and even second cousins, the sons of *karrales*, were referred to as *ermanos primargios*.”

so there you go. and there’s only something on the order of a million and one dialects in italy, so who knows how many different terms there might be for cousins in “italian” (and how those terms might differ regionally)?

from anglo-saxon england, from the laws of wulfstan (d.1023), apparently the punishment (or one of the punishments) for violating the incest laws was a fine — a fine reckoned based upon how closely you were related to your partner in crime. sounds like it was a bit like applying some sort of wergeld calculation in order to try to enforce the cousin marriage bans. never heard this before [pg. 227]:

“There is particular concern and precision in the laws associated with Wulfstan: ‘if anyone commits incest, he is to pay compensation according to the degree of relationship, whether by wergeld or by fine or by all his possessions. It is not equal whether a man has intercourse with his sister, or with a more distant relation.’ Laws composed by Wulfstan prohibited marriage ‘within the sixth degree of relationship, that is within the fourth knee [*cneowe*]’, thus prohibiting marriage to fourth cousins, or marriage ‘with the widow of a man as nearly related to him as this’.”


(note: comments do not require an email. wulfstan.)

i was thinking about the idea of genetic pacification, specifically via the state or some authority eliminating the most violent individuals from a population (like by execution as frost and harpending propose happened in medieval europe — see also here), and i got to wondering how other societies have meted out justice to violent offenders.

so, like hermione granger, i went to the library (heh! — no, really i just googled it) and found a few interesting things. one of them is that in traditional igbo society, the punishment for murder was left in the hands of the culprit(!) [pg. 285]:

“[T]he Igbo believe that there are both divine and man-made laws, but that the greatest penalties are reserved for breaches of divine law. Thus, a murderer would not be put on trial, because if the evidence were clear and convincing no earthly court could have jurisdiction. Indeed, the penalty prescribed by Igbo tradition is that the murderer is expected to hang himself…. [A]ny Igbo guilty of breaking a divine law would be required to do penance personally to be restored to the good favor of the gods.”

now you might think that leaving enforcement of the death penalty up to the criminal is a really bad idea — and maybe it is — but i was thinking that it might work in a shame culture. an especially strong shame culture. certainly worked in japan (at least among certain classes), which admittedly is the poster child of shame cultures.

couldn’t figure out whether or not igbo society is a shame culture, although most societies lean more toward shame than guilt. however, i do know that igbos — igbo slaves in the new world — had a reputation for committing suicide [pgs. 52-53 and 127-128 – links added by me]:

“Suicide as an ethnic or cultural ‘trait’ is usually associated with Bight of Biafra imports, especially Igbos, in the Americas. As Daniel Littlefield contends, the principle reason why they were among the least desirable of African slave imports was due to the perception among American planters that Igbo or Calabar slaves had ‘a deplorable penchant for committing suicide.’ More recently, Michael Gomez has summarized the historical and contemporary view of Igbos, noting that ‘the sources are therefore unanimous in ascribing to the Igbo greater self-destructive tendencies….’

“Biafran imports were often much cheaper than other Africans. In 1755, Igbo slaves sold in Charleston for only £270 while Africans from other regions cost £300. Henry Laurens — the noted slave merchant of colonial South Carolina — claimed in 1755 that very few Calabar Africans could be sold in the Charleston slave market when others were available. He then recommended the importation of a ‘few fine Negro Men, not Callabars.’ In a letter to Richard Oswald dated May 17, 1756, Laurens also noted that ‘slaves from the River Gambia are preferr’d to all others with us save the Gold Coast, but there must not be a Callabar among them.’

“Much of this prejudice against Igbos and others from the Bight of Biafra was due to their alleged propensity to commit suicide. Guerard complained, ‘As to bite Slaves, I protest against them at any Rate there has been so many instances of their Distroying themselves that none but the Lower sort of People will Medle with them.’ South Carolina planters who did purchase Calabar slaves were advised to buy only ‘young People from 15 to 20’ who were typically ‘not accustom’d to destroy themselves’ like their older compatriots. Based on this assumption, Henry Laurens advised that Bigt of Biafra slaves under the age of fourteen should be the only Africans from that region purchased by Low Country planters. In another assessment by ship captain John Adams, who made ten visits to the Niger River delta between 1786 and 1800, the Ibgo were considered to be ‘naturally timid and desponding, and their despair on being sent on board a ship is often such that they use every stratagem to effect the commission of suicide, and which they would often accomplish, unless narrowly watched.'”

can’t say as i blame them.

the usual explanation offered today for why slaves from the bight so often committed suicide is the belief, widely shared by peoples in west africa, in spiritual transmigration — when you die, you get to go to where your friends and family are — where your living friends and family here on earth still are. so, maybe death was not viewed as a bad solution for a biafran captive who was dragged halfway across the world. in their minds, they’d get to go home. alternatively, maybe they just didn’t want to be slaves. ooorrr…maybe there was an element of shame involved, but that’s pure speculation on my part. would be interesting to find out, though.

no idea if violence is lower among the igbo than other west african groups. need to find out. interesting that they were described as “naturally timid” though.

a further thought i had is that perhaps long-term inbreeding can amplify shame in populations. the japanese used to marry their cousins (although i don’t know how far back that practice went) and they have an extremely strong shame culture. the arabs, too — long-term inbreeders and there’s a lot of shame there, too (family honor, etc.). perhaps shame is a sort-of familial altruism, i guess is what i’m trying to say. dunno. Further Research is Required TM.

in the wake of chanda chisala’s post over at, several people asked me so what about the igbo? are they inbreeders or what?

i haven’t read much about the igbo, but what i do know is that they avoid all cousin marriage. don’t know how far back this goes — whether it’s pre-the introduction of christianity there or not. might be. might not be. they do practice polygamy, though, especially traditionally, which ought to narrow the genetic relatedness between individuals in the population in a way similar to cousin marriage, but…well, more on polygamy another day.

very interestingly, in their traditional society, the igbo had a “quasi-democratic republican system of government” — that’s if wikipedia is to be believed. the igbo also had non-kinship based trading associations or “houses” [pg. 137]:

“In order to exploit the rapidly expanding trade [with the newly arrived europeans] and now having the resources to do so, the delta peoples living in single settlements on the rivers and islands surrounded by protective intricate waterways developed systems of governance for their own city-states. City-states are well known in history, and many have in common a maritime presence. In Europe there were the famous Greek city-states, Athens and Sparta. In East Africa there were the coastal Swahili city-states of Mombasa, Malindi, and Kilwa among others. On the coast of West Africa there were the city-states of the Niger Delta whose citizens devised the means to adminster law and order, justice, and to make war and peace in order to promote their commerce. Each delta city-state, like those of the Greeks, had its own distinct methods of governing. Some had kings elected by the heads of wealthy and prominent families — Bonny, New Calabar, and Warri. Others were like small republics, ruled by the members of political organizations not unlike senates — Brass and those on the Cross River in Old Calabar — Creek Town, Henshaw Town, Duke Town, and Obutong. In the city-states of Old Calabar the *ekpe* or Leopard Association of wealthy men, mostly merchants, ruled the town principally to insure the flow of peaceful trade. Anyone was free to join the *ekpe* if they could afford the exorbitant entry fee that insured that those in power represented only the interests of the wealthy merchants. They regulated the terms of trade with the Europeans and made the rules by which the community was governed by its constituent organizations, known as the ‘house system.’

“Traditional African societies were based on the clans and lineages of large families that were not always the most effective means to carry on business. Rather than the family firm, the house was a cooperative commercial trading company run not by kinship but by the ability of the head of the house, his immediate family, and a host of assistants, servants, and even slaves whose status in the company depended on their success in promoting its trade rather than kinship ties or social privilege.”

the ability to form strong, functioning non-kinship based associations like that usually goes along with long-term outbreeding, in my experience.

well, that’s all i’ve got for you for now.

i finally have admitted to myself — and now i will to you, too, dear readers — that i am too unwell at the moment to write my (what will be a lengthy!) response to prof. macdonald or, unfortunately, to work on my promised (threatened!) medieval manorialism series. am having difficulties putting two coherent thoughts together these days. (yeah, yeah — more so than usual! (~_^) ) so, i’ll just have to leave those on the back burner for now and get to them when i can. i’m due to have some medical tests done in the next few weeks, so hopefully after that, i can get myself sorted out and back in working order. in the meantime, i’ll do some more flakey posts like this which just involve me rambling some of my random thoughts.

more soon! (^_^)

previously: quick review of frost and harpending on the genetic pacification of europeans and fulani, hausa, igbo, and yoruba mating patterns

(note: comments do not require an email. igbo yam festival…in dublin, ireland!)

there’s been a theory floated for a few years now that there was a sort of apartheid system in early anglo-saxon england in which the angles and saxons and jutes didn’t really mix with the native britons. or vice versa. from thomas, stumpf, and härke:

“Reproductive isolation and differential social status along ethnic lines is a frequent, temporary consequence of conquest and settlement, the best-known modern case being the Apartheid system in South Africa. In the post-Roman period, intermarriage between dominant immigrants and subject natives was banned in Visigothic France and Spain in the late fifth and early sixth century (King 1972). The Normans in eleventh- and twelfth-century England operated a conquest society in which the native English and Welsh had a lower legal status than Normans (Garnett 1985), and intermarriage, where it happened, was predominantly unidirectional, i.e. Norman men marrying English women. In Anglo-Saxon England, elements of an apartheid-like society can also be perceived in a Wessex law code of the seventh century which distinguishes clearly between Saxons and ‘Welsh’ (Britons) and gives the former a significantly higher legal status, some two centuries after the initial immigration (Whitelock 1979). Archaeological and skeletal data (Härke 1990, 1992), as well as textual evidence (Woolf, 2004), have been used to suggest a situation of limited intermarriage between immigrant Anglo-Saxons and native Britons until the seventh century when this distinction began to break down.”

for more on this theory, see: Anglo-Saxon immigration and ethnogenesis.

now it seems as though the recently published genetic study by leslie et al. may back up this idea. from the Supplementary Information [pdf – pg. 18]:

The Cent./S England inferred admixture date is older, at around 1200 years ago. This is moderately, but significantly, more recent than the historically accepted time of approximately 1400 years ago (around 600) for the Anglo-Saxon migration into England. This discrepancy is unlikely to be explained by errors in our human generation time (we used 28 years) because an unlikely generation time of 33 years or higher would be required to account for this difference. Instead, an important point is that the date of admixture cannot be earlier than the arrival of a group, but can be later if mixing did not occur for some period (e.g. if the Anglo-Saxon community remained distinct for some period after arrival), or if mixing took place gradually, and initially at a relatively slow rate.”

so, they’re saying that intermarriages between the anglo-saxons and the native britons didn’t really get going until the 800s.

both the anglo-saxons and probably the native britons (presuming they were rather like the native irish and scots), like every other pre-christian northern european group, married their cousins to some degree or another. we know for certain that the anglo-saxons did, because augustine of canterbury wrote several frantic letters to pope gregory the great about the problem (he viewed this as a problem since already by this point in the 600s the church had banned marriages to close cousins).

across the channel in the frankish kingdoms, cousin marriage didn’t became socially unacceptable until the 800s, even though there were local bans issued by bishops in the frankish kingdoms as early as the 500s. as i wrote in a previous post:

from “An Unsolved Riddle: Early Medieval Incest Legislation” in Franks and Alamanni in the Merovingian Period: An Ethnographic Perspective (1998), a collection of papers from an “historical archaeoethnological” conference [pgs. 109-110]:

“In the course of the eighth century the Frankish campaign against incest gained momentum, aided by papal decrees and letters which began to circulate in the North (De Jong 1989:38-41). When it came to blood relations papal guidelines were more radical than Frankish episcopal and royal decrees, but in other respects — such as spiritual kinship — Rome and the Frankish leadership saw eye to eye right from the beginning. Letters sent from Rome to Boniface reveal an increasingly rigid papal position. Gregory II forbade all unions between blood relations and affinal kin (‘*quamdiu se agnoscunt affinitate propinquos*’), but permitted the recently converted a marriage ‘*post quartam generationem*’; his successor Gregory III withdrew any such privilege, assuring Boniface that marriage within the seventh *generatio* was out of the question….

“In practice…it did not make any difference whether one forbade marriage ‘until the seventh *generatio*’ (Gregory III), or proclaimed an unspecified ban on all kinswomen and affines (Gregory II). Both meant the same: marriage and kindred did not go together. Pope Zachary expressed this clearly in 743, stating that no Christians were permitted to marry if they were in any way related to each other (Werminghoff 1904:19-21). Avoidance of kin-marriage had become one of the defining criteria of Christianity….”

by the 800s [pg. 120]:

By the ninth century, a marriage in the third *generatio* [i.e. second cousins – h.chick] had become scandalous, but the fourth generation remained a viable option, along with a whole range of more distant kin (Le Jan 1995:316-17). This pattern persisted well into the tenth and eleventh centuries.”

i’m not one hundred percent certain, but i think that this shift to the regular avoidance of cousin marriage by the franks probably had something to do with the establishment of parish churches in the 700 and 800s by pepin the short and charlemagne. once there was “a church in every village,” the message that cousin marriage was not permitted would’ve been more readily heard, and, perhaps, more easily enforced (by the local priest).

i don’t know anything about the establishment of parishes in england (yet), but perhaps the english — the anglo-saxons and britons — were on a similar trajectory as the franks with regard to cousin marriage. perhaps they, too, didn’t really start to take the bans seriously until sometime in the 800s, despite there having been some very early laws forbidding cousin marriage in some of the anglo-saxon kingdoms (like in the late 600s in kent). if there was such a delay in avoiding cousin marriage in england in the seventh and eighth centuries, then there wouldn’t have been much intermarriage between the anglo-saxons and britons during those centuries simply because they all would’ve been still mostly marrying their own cousins or other close kin (i.e. fellow clan or kindred members). if so, then genetic exchange between the groups would’ve become much more likely once cousin marriage began to be consistently avoided. maybe it took the church and its bans on cousin marriage to end anglo-saxon apartheid.

just a thought. Further Research is RequiredTM. (^_^)

previously: free cornwall now! and anglo-saxon mating patterns

(note: comments do not require an email. anglo-saxon rings.)

(note: i’ll post the punch line to the do you think like a westerner? post tomorrow…or maybe tuesday. (^_^) )

further to my notion that various jewish populations have tended to imitate the mating patterns (eg. cousin marriage or not) of the broader societies in which they have been situated — at least over the last millennium or so (dunno about the ancient hebrews) — here are some numbers on the types of cousin marriage found in the iranian jewish population. remember that consanguineous marriage is quite high among iranian jews — something on the order of 25%. from Outcaste: Jewish Life in Southern Iran [pg. 112]:

jews - iran- cousin marriage types

notice that nearly one third (3.06%) of all the first cousin marriages (9.88%) are to the father’s brother’s daughter (fbd or FaBrDa in the table). another 1.41% of the marriages are to other patrilateral parallel cousins, probably paternal second cousins. (that’d be father’s father’s brother’s son’s daughter marriage, if you must know. =P or ffbsd marriage! never mind. don’t think about it too hard.)

so ca. 4.5% of iranian jewish marriages are to a patrilateral parallel cousin to some sort. remember that patrilateral parallel cousin marriage (fbd marriage…or ffbsd marriage!) is very unusual. most of humanity avoids it. the vast majority of populations that practice cousin marriage practice maternal cousin marriage — usually cross-cousin maternal marriage or mbd marriage. it’s only the arabized world which favors parallel paternal cousin marriage (and the tswana). it’d be too much of coincidence, i think, for iranian jews to have invented fbd marriage all on their own — i’m betting they picked it up from other iranian peoples after the arabs introduced it to the region.

uuunnnnleeesssss…the jews (also?) introduced it to the region, as they are thought to have done in arabia. hmmmm…?

interestingly, persian jews seem to have put their own twist onto parallel cousin marriage and that is that they also marry maternal parallel cousins (mother’s sister’s daughter or msd marriage or MoSiDa in the table). that form of parallel cousin marriage is even more unusual than fbd marriage. i don’t know of any population that does it. nearly everyone on the planet avoids it. it might, however, have seemed natural to this group of jews — natural, that is, if you’re thinking of adopting parallel cousin marriage at all — since jews have had a very long tradition of allowing/practicing maternal uncle-niece marriage. there are more than two times the number of maternal uncle-niece marriage (SiDa) than paternal uncle-niece marriage (BrDa) in this persian group, for instance. (all of this harkens back to the idea that you know who an individual’s mother is, but you can never be sure who the father is.) i think this is another indicator that persian jews picked up the idea of parallel cousin marriage from the surrounding population (although perhaps it was back in the levant?), and then they adapted it to their own practices. could be wrong. Further Research is RequiredTM.

if (IF) i’m right — going by this persian evidence and the medieval german jewish evidence — that jews have generally adopted the mating patterns of their host populations, then an interesting question is, do other subgroups do this, too? will, for instance, muslim immigrants to the west adopt outbreeding? dunno. mixed signals here. in britain, where most pakistanis are from the kashmir and punjab regions, the total cousin marriage rate in the 1980s (that’s first and second cousins) was 67% [pg. 10]. the rate for all-punjab back in pakistan was 50.3% [pg. 16]. that certainly looks like an increase in cousin marriage in the immigrant population. however, meanwhile in norway, two studies found that pakistani-born pakistanis had higher rates of cousin marriage than norwegian-born pakistanis (37.5% & 34.7% versus 30.1% & 27.1% – pg. 11 – don’t know where pakistanis in norway are from). that looks like a decrease. all things considered, it’s probably too early to tell what the trend(s) might turn out to be.

korotayev and other russian anthropologists have argued — convincingly, imho — that father’s brother’s daughter’s (fbd) marriage was spread by the arabs, since its maximum range today (looking away from the outlier tswana in southern africa) corresponds to the eighth-century caliphate. they further argue that, as part of a more general “arabization” process, the conquered populations emulated their conquerors in all sorts of ways, both in order to succeed in this newly constructed society and, quite possibly, since they viewed the arabs’ culture as somehow superior to their own. the arabs were the conquerors, after all. they must’ve been doing something right! the arabs may even have impressed upon their new subjects that their culture was, indeed, the better one. if they’re right, it seems much less likely to me that immigrant groups to the west will copy our mating patterns if we don’t impress on them that we think they’re important and the right way to go.

previously: historic mating patterns of ashkenazi jews and jewish inbreeding and father’s brother’s daughter’s marriage

(note: comments do not require an email. persian jewish girl. (^_^) )

william hamilton wondered if renaissances/enlightenments happened in places roughly 800 years after some hardy altruism genes were introduced by barbarians into panmictic (really outbred) populations. i wonder instead if what happens is that renaissances/enlightenments occur after ca. 500 years or so of outbreeding which results in nepotistic altruism (or clannishness) being reduced or even mostly eliminated which, in turn, leads to greater cooperation and reciprocal altruism within the populations — conditions i think you might need to have a renaissance at all (see also here).

where intensive outbreeding (and manorialism) happened in medieval europe — and there is a lot of good, strong evidence for it — certainly seems to match well with where the european renaissance occurred. after some fits and starts in the 500s to 700s, the practice of avoiding close cousin marriages really took hold in exactly the areas where the renaissance/reformation/scientific revolution/enlightenment later happened — i.e. core europe — in short: england, france, the netherlands, germany, and northern italy. scandinavia a bit, too. oh…and the lowlands of scotland.

the evidence for outbreeding in ancient greece is much more tenuous. it appears fairly certain that the upper classes outbred during the archaic period in greece (800-480 b.c.). whether they outbred during the entire time period or began the practice sometime before or after 800 b.c., i don’t know. it may also be, judging by something hesiod said, that the lower classes followed suit, but it’s impossible to know for certain going by just one comment from one ancient writer.

some circumstantial evidence that might offer further support to the outbreeding-in-archaic-greece theory is that, in the 400s to 200s b.c., there was a shift in kinship terminology in ancient greece. the distinctions in the greek language between the paternal and maternal sides of the family began to disappear — for example, uncles on both sides came to be called just “uncle,” rather than there being specific words for paternal vs. maternal uncle, and so on and so forth. the same sort of linguistic shift happened in medieval europe. in germany, for instance, that shift happened between the 1100s and 1400s. at the end of the day, all cousins came to be called simply “cousin” rather than “father’s brother’s cousin” or “mother’s brother’s cousin.” the lesson seems to be: change the kinship structures and the long-term mating patterns in a society, and it shouldn’t be surprising that the kinship terminology will also change. no need to specify different sorts of cousins if all of them are off-limits as marriage partners.

michael mitterauer points out that there was a time lag in the linguistic shifts in medieval europe — the terminology changed ca. 300 to 600 years after the mating patterns began to change. perhaps something similar happened in archaic greece — the linguistic shift happened in ca. the 400s to 200s b.c. so perhaps we can infer that the mating patterns had changed to a more outbred form a few hundred years earlier. maybe right around the end of the greek dark ages and the beginning of the archaic period. dunno. complete speculation.

now i’ve come across another piece of circumstantial evidence that outbreeding may have been happening in archaic greece and that is that there was a(n incomplete) shift in the society during the time period from being a shame culture to being a guilt culture. i’m getting this from The Greeks and the Irrational, a book originally published in 1951 and written by classical scholar e.r. dodds (who was kicked out of oxford for supporting the easter rising — troublemaker! (~_^) ). presumably there have been works criticizing dodd’s thesis written since the 1950s, but i’m afraid i haven’t read any of them yet. i’m just going to run with dodd’s idea for now, but, please, consider this a sort-of thought experiment. more speculation.

first of all, in shame cultures, bad behavior is checked by the fear of being caught — of being shamed and embarassed. in guilt cultures, bad behavior is checked by one’s inner voice — feelings of guilt occurring before any action is taken. these are behavioral traits that must have been variously selected for in different human populations. secondly, shame cultures are all tied up with honor — especially family honor. japan — with its meiwaku and seppuku — is the classic example of a shame culture, but china with its confucian filial piety is not far behind. the arabized populations are definitely shame cultures with their honor killings and all their talk of respect. even european mediterranean societies are arguably more honor-shame cultures than guilt cultures [pdf].

if you’ve been reading this blog for any amount of time, you’ll recognize all of those shame cultures as having had long histories of inbreeding: maternal cousin marriage was traditionally very common in east asia (here’re japan and china); paternal cousin marriage is still going strong in the arabized world; and cousin marriage was prevelant in the mediterranean up until very recently (here’s italy, for example). it’s really, once again, the outbred northwest “core” europeans who are unique here with their guilt culture (although perhaps there are other guilt cultures out there as well). my guess is that long-term inbreeding tends to result in shame-honor cultures, while long-term outbreeding leads to guilt cultures. i’ve said so before.

back to dodd, his thesis is that ancient greece went through something of a transition from a shame to a guilt culture, but that shift was incomplete. the trend may even have reversed in classical athens. dodd points to several thematic shifts in greek literature from the iliad to the writings of plato including: a move away from blaming human failings on atē or the direct, external influences of the gods to more personal “demons,” often seen only by the individual person; the gradual adoption of the idea that individual humans have “souls” or independent “personalities”; a move away from the idea that people’s failings are due to a lack of knowledge (again coming from outside the person) as opposed to, perhaps, their own culpability; that zeus over time becomes more and more a dispenser of justice rather than just a being who capriciously interferes in human affairs (justice being important in guilt cultures as opposed to revenge in shame-honor cultures); and that philosophers and thinkers increasingly complained that the inheritance of guilt down through a family line was unjust. here from dodd on that last point [kindle locations 669-671]:

“Solon speaks of the hereditary victims of nemesis as άυαίτιοι, ‘not responsible’; Theognis complains of the unfairness of a system by which ‘the criminal gets away with it, while someone else takes the punishment later’; Aeschylus, if I understand him rightly, would mitigate the unfairness by recognising that an inherited curse may be broken.”

the idea that only the transgressor should be punished (as in guilt cultures) as opposed to additional or all of his family members (as in shame-honor cultures) doesn’t actually occur to these writers, so they haven’t quite arrived fully into a guilt culture, but they do seem to have been on the way there. much more so than earlier writers anyway. again, dodd emphasizes that [kindle locations 587-588]:

“[M]any modes of behaviour characteristic of shame-cultures persisted throughout the archaic and classical periods. There is a transition, but it is gradual and incomplete.”

the transition may have been incomplete — in fact, may have even gone into reverse — because inbreeding (cousin marriage) became increasingly common in classical athens (see here). from “Agnatio, Cognation, Consanguinitas: Kinship and Blood in Ancient Rome” in Blood and Kinship: Matter for Metaphor from Ancient Rome to the Present [pgs. 24-26], we saw in a previous post that while “aristocrats in early [archaic] Greece…married beyond the limits of their *patris*”, in classical athens “members of the *anchisteia*, the legally defined kinship group including first cousins once removed, were the preferred marriage partners.” the ancient greeks might’ve gone from being a (presumably) inbred/shame culture in the dark ages, to an outbred/quasi-guilt culture in the archaic period, and back to an inbred/shame culture over the course of the classical period. maybe. Further Research is RequiredTM.

(yes, i know. it’s all very tenuous. i told you it was speculative!)

in any case, evolution is not progressive. (heh! i’ve just been dying to say that. (~_^) ) there’s nothing to say that evolution cannot go in reverse, although perhaps it wouldn’t go back down the exact same pathway it came up. there’s no reason why we — or, rather, our descendants — couldn’t wind up, as greg cochran says, back in the trees*.

i think the way to think of the evolution of behavioral traits like nepotistic and reciprocal altruism in humans — especially perhaps in recent human evolution — is like a big simmering cauldron of stew where bubbles of certain behaviors rise up in some places only to sometimes pop and deflate and almost disppear again. outbreeding appears to have occurred many places, although whether or not over the long-term is not always clear: archaic greece (maybe), ancient rome, the bamileke of cameroon, the igbo of west africa, the turkana of east africa, the semai of malaysia, the bushmen of southern africa (aka The Harmless People), and europeans since the early medieval period — especially northwest europeans. the ancient greek experiment seems to have run out of momentum and collapsed on its own; the roman example probably popped thanks to the barbarian invasions; and the northwest european one is…currently ongoing. for now.

previously: renaissances and the transition from shame to guilt in anglo-saxon england (and “core” europe) and archaic greek mating patterns and kinship terms and ελλάδα

*“Many were increasingly of the opinion that they’d all made a big mistake in coming down from the trees in the first place. And some said that even the trees had been a bad move, and that no one should ever have left the oceans.”

(note: comments do not require an email. archaic greek dude.)

on the recommendation of just about everybody that i know online (thanks, almost everybody!), i am reading graham robb’s The Discovery of France.

this, below, is by far the funniest story so far! and there are a LOT of funny stories like this in the book…and i’m only about a quarter of the way through! great stuff. hbd chick is amused! =P [pgs. 27-28 – link added by me]:

“An expedition into tribal France could begin almost anywhere and at almost any time. A hilltop in the Aveyron, for instance, where the limestone plateaux of the Causses turn into a crumpled map of rocks and gorges. The year is 1884. The priest of Montclar has found an exciting diversion from the monotony of life in a small town. His telescope is trained on a battlefield in the valley below. An army of men, women and children, wielding cudgels and lugging baskets of stones, is advancing on the village of Roqueceziere. But scouts have been posted. Another army has already emerged from the village and is preparing to defend its territory.

“On the bare rock that towers above the village, turning its back to the battle, is a colossal cast-iron statue of the Virgin Mary. The statue has been funded by public subscription — something of a miracle in this impoverished region — and has recently been placed on the rock to commemorate a successful mission.

“Incensed to see the sacred effigy pointing its bottom at their village, the invaders have come to turn it around. The battle rages for hours. Several people are seriously injured. At last, the Roquecezierain lines are breached and the statue is worked around to face the other village. To prevent a full-scale war, the Church authorities find a compromise. The Virgin is rotated ninety degree, supposedly so that each village can see half of her face. However, she now looks east-north-east, towards Saint-Crepin, which contributed more than half the cost of the statue, and still had her back turned to the little clutch of houses at her foot.”

heh! =P i think this must be the statue here:


it should be noted that roquecezière (indicated by red dot) is down in midi-pyrénées in a region having, for france, pretty high cousin marriage rates historically…

roquecezière - cousin marriage

…and it’s also fairly far away from the “core” of core europe (green circle here).

previously: the auvergnat pashtuns

(note: comments do not require an email. roquecezière.)

emil kirkegaard published an interesting paper recently — well, actually, he’s published a whole slew of interesting papers recently! — but i want to look at something in this one that he coauthored with john fuerst: Educational attainment, income, use of social benefits, crime rate and the general socioeconomic factor among 71 immigrant groups in Denmark.

it’s this chart right here which appears on page 10:

emil's outlier

the curious point on this chart is the flying outlier of lebanon. oftentimes exceptions prove the rule, but occasionally they’re indicators that something might be up. why do lebanese immigrants in denmark (many of whom, i take it from googling around, are actually palestinian refugees) do soooo poorly socio-economically when they don’t score so high on the islamic scale (presumably because about one-third of them are christians, if the joshua project is to be believed)?

emil is skeptical of the inbreeding-can-lead-to-social-and-economic-dysfunction theory, and that’s ok! skepticism is a good thing. but i think that he and john should take it into consideration in this instance. a study from the 1980s found that 16.5% of lebanese christians were in consanguineous marriages (and nearly 30% of lebanese muslims were). sixteen and a half percent is in the neighborhood of the cousin marriage rates in south-central italy, another population not especially known for its great ses achievements, so it’s maybe not surprising to find that the lebanese in denmark are socio-economically quite dysfunctional even though a large portion of them aren’t muslims. we see this pattern over and over again across the world: too much inbreeding (eg. cousin marriage) especially over time in a population and you wind up with social and economic dysfunction, corruption, rampant nepotism, etc., etc.

while it is true that all of the pops in the upper right-hand corner of the chart are majority muslims pops, what they also have in common is a long history of cousin marriage including very close (father’s brother’s daughter/fbd) cousin marriage. the lebanese — including lebanese christians — also fall into this group (although lebanese christians don’t marry their fbds much).

in fact, if you were to draw a horizontal line at .0 across the chart there, no long-term outbreeding population would fall above it. they all actually cluster in the lower left-hand corner of the chart (in other words, the most successful ses-wise): usa, canada, belgium, germany, finland, etc. and as you move upwards on the chart (i.e. away from ses success), you increasingly encounter pops that having been inbreeding for longer: russia, greece, india, china, bosnia, macedonia.

islam might correlate with poor ses in immigrant groups in denmark (and elsewhere), but i suspect that the extent of their history of inbreeding is a more direct cause of the dysfunctionality of these groups.

what the world needs is a good index of inbrededness (rates+history). am workin’ on it! (^_^)

btw, if you’re not regularly checking out the openpsych journals, you should be! “open access, free to publish, open peer review.” good stuff! (dunno why i don’t have them in my blogroll yet. need to do some updating to the ol’ blog here!)

previously: inbreeding amongst christian arabs

(note: comments do not require an email. not emil’s relation.)


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