linkfest – 04/19/15

a linkfest! =D

Experimental evolution reveals hidden diversity in evolutionary pathways“Our findings show that parallel genetic evolution is strongly biased by constraints and we reveal the genetic bases. From such knowledge, and in instances where new phenotypes arise via gene activation, we suggest a set of principles: evolution proceeds firstly via pathways subject to negative regulation, then via promoter mutations and gene fusions, and finally via activation by intragenic gain-of-function mutations. These principles inform evolutionary forecasting and have relevance to interpreting the diverse array of mutations associated with clinically identical instances of disease in humans.”

Selectionism Strikes Back! – from razib.

Genomes carry a heavy burden“Most people’s DNA contains genetic mutations that are potentially lethal to offspring…. Most people carry one or two genetic mutations that can cause early death or infertility in their offspring….”

World’s oldest stone tools discovered in Kenya“Researchers…say they have found the oldest tools made by human ancestors — stone flakes dated to 3.3 million years ago. That’s 700,000 years older than the oldest-known tools to date, suggesting that our ancestors were crafting tools several hundred thousand years before our genus Homo arrived on the scene. If correct, the new evidence could confirm disputed claims for very early tool use, and it suggests that ancient australopithecines like the famed ‘Lucy’ may have fashioned stone tools, too.”

Neanderthals manipulated the bodies of adults and children shortly after death

Neandertal flutes debunked – @dienekes’.

IQ prediction from structural MRI – from steve hsu. see also: MRI-Based Intelligence Quotient (IQ) Estimation with Sparse Learning.

New brain science shows poor kids have smaller brains than affluent kids – see also: Credit, where credit is due, to Lyndsey Layton and Income, brain, race: Prof Kimberly Noble replies and Howitzer or Katyusha: Reply to Prof Noble at dr. james thompson’s blog. – and see also: In today’s social science, wishing makes it so – from charles murray.

Gene study may explain why some remain quick thinkers“Genetic differences could explain why some people are quicker thinkers in middle age and later life, a study of data from 30,000 people suggests.” – see also: GWAS for executive function and processing speed suggests involvement of the CADM2 gene.

Prediction of brain age suggests accelerated atrophy after traumatic brain injury – h/t stuart ritchie! who tweeted: “Super-cool new paper on how to predict someone’s age just from a brain image (r = .92!)”

National Wealth and IQ at the Edge: American Exceptionalism, East Asian Mediocrity – anatoly karlin’s “big-ass blog on national wealth, IQ, HBD, East Asians, smart fractions, etc.” (~_^)

In the beginning was the Word – dr. james thompson blogs on the recent woodley et al. paper “By their words ye shall know them: Evidence of genetic selection against general intelligence and concurrent environmental enrichment in vocabulary usage since the mid 19th century.”

Born That Way – from greg cochran.

Female Same-Sex Attraction Revisited – from jayman.

Examining the S factor in Mexican states – from emil kirkegaard.

Sex differences and vulnerability: how the male-female divide affects health“[S]ome studies have shown that premature baby girls will grow up to suffer greater language deficits than premature boys, whereas boys exposed to certain prenatal toxins will suffer greater deficits to spatial skills than girls similarly exposed, but because sex differences were never the original focus of the research no one, until Geary, has united these sex specific developmental problems and placed them in evolution’s bigger picture. Geary explains, ‘Sexually selected traits are the first to go; for example, low level exposure to prenatal toxins will affect play in boys but not their IQ: if you don’t measure the right thing you will fail to detect underlying problems.'” – h/t steve stewart williams!

Men up to five times more likely to commit sex crimes than the average male if they have brother or father convicted of a sex offence – h/t claire lehmann! who tweeted: “Survey of 21,566 men convicted of sex crimes from 1973- 2009 has revealed a strong genetic component to sex offending.” – see also: Sexual offending runs in families: A 37-year nationwide study.

Aggressive-Antisocial Boys Develop Into Physically Strong Young Men“We found that males’ antisocial tendencies temporally precede their physical formidability. Boys, but not girls, with greater antisocial tendencies in childhood attained larger increases in physical strength between the ages of 11 and 17. These results support sexual selection theory, indicating an adaptive congruence between male-typical behavioral dispositions and subsequent physical masculinization during puberty.”

Childhood Self-Control and Unemployment Throughout the Life Span: Evidence From Two British Cohort Studies“Analyzing unemployment data from two nationally representative British cohorts (N = 16,780), we found that low self-control in childhood was associated with the emergence and persistence of unemployment across four decades. On average, a 1-SD increase in self-control was associated with a reduction in the probability of unemployment of 1.4 percentage points after adjustment for intelligence, social class, and gender.”

Enlisting in the Military: The Influential Role of Genetic Factors“Given that enlistment in the U.S. military is completely voluntary, there has been a great deal of interest in identifying the various factors that might explain why some people join the military, whereas others do not. The current study expanded on this line of literature by estimating the extent to which genetic and environmental factors explained variance in the liability for lifetime participation in the military. Analysis of twin pairs drawn from the National Longitudinal Study of Adolescent to Adult Health (Add Health) revealed that 82% of the variance was the result of genetic factors, 18% of the variance was the result of nonshared environmental factors, and none of the variance was accounted for by shared environmental factors.” – from brian boutwell et al.

Risk of Suicide Among US Military Service Members Following Operation Enduring Freedom or Operation Iraqi Freedom Deployment and Separation From the US Military“Findings do not support an association between deployment and suicide mortality in this cohort. Early military separation (<4 years) and discharge that is not honorable were suicide risk factors.” – h/t michael story!

Verbal ability as a predictor of political preferences in the United States, 1974–2012“[H]igher vocabulary scores are associated with a greater likelihood that people place themselves on the ideological and political spectrum and that they vote in presidential elections, but have only small relationships with liberal-versus-conservative self-identification.”

Do our genes tell us how to vote? Study of twins says they might

On the Malleability and Plasticity of the History of the Blank Slate and 21st Century Moral Philosophy Advances Boldly into the 19th Century – from helian.

More on the younger Franz Boas – from peter frost.

Surnames and Y-Chromosomal Markers Reveal Low Relationships in Southern Spain – ruh roh.

New study finds genetic predisposition for noise-induced hearing loss

New function of obesity gene revealed

The placebome: Where genetics and the placebo effect meet

Chimps That Hunt Offer a New View on Evolution“[A] 10-year study of chimpanzees in Senegal shows females playing an unexpectedly big role in hunting and males, surprisingly, letting smaller and weaker hunters keep their prey. The results do not overturn the idea of dominant male hunters, said Jill D. Pruetz of Iowa State University, who led the study. But they may offer a new frame of reference on hunting, tools and human evolution. ‘We need to broaden our perspective,’ she said.”

Upper Palaeolithic ritualistic cannibalism at Gough’s Cave (Somerset, UK): The human remains from head to toe“Our present analysis of the postcrania has identified a far greater degree of human modification than recorded in earlier studies. We identify extensive evidence for defleshing, disarticulation, chewing, crushing of spongy bone, and the cracking of bones to extract marrow. The presence of human tooth marks on many of the postcranial bones provides incontrovertible evidence for cannibalism.”

Yes, You Can Catch Insanity“A controversial disease revives the debate about the immune system and mental illness.” – pediatric autoimmune neuropsychiatric disorders or “PANDAS”.

Hatfield and McCoy Feud — The Real Thing

Colors help set body’s internal clock“[Mice] use light’s changing color to set their own clocks, a finding that researchers expect will hold for humans, too.”

The Myth of the Angry Atheist“[T]hese results support the idea that people believe atheists are angry individuals, but they do not appear to be angrier than other individuals in reality.”

Flowers Are “Darker” at Lower Latitudes“UV radiation may explain why plants and animals closer to the equator come in darker varieties.”

The Disease That Turned Us Into Genetic-Information Junkies – brief history on tay–sachs disease research.

Antibiotic Resistant Bacteria Could Predate Antibiotics“A South American tribe, called the Yanomami, which was isolated for about 11,000 years prior to 2009, have gut bacteria that carry antibiotic resistance genes, according to new research. The Yanomami’s microbiome is far more diverse than that of Europeans or North Americans, but it also contains antibiotic resistant genes, despite never having had antibiotics. The findings suggest antibiotic resistance predates antibiotics, although it is possible the Yanomami ingested naturally occurring antibiotics in soil at some point.” – see also: The microbiome of uncontacted Amerindians.

Rotherham Worker ‘Told To Give Girls To Abusers’“The ex-protection worker says she repeatedly raised concerns about men taking girls away but her boss told her to ‘let them go’.” – also: State wards being groomed for prostitution by paedophile gangs“Organised gangs of paedophiles are grooming state wards as young as 12 for prostitution. Veteran child protection workers have told the Herald Sun they are powerless to protect the children in their care and that the sexual exploitation of state wards is ‘endemic’…. Victoria Police has set up a taskforce to investigate a gang of Afghani men in Dandenong suspected of preying on teens in care.” – australia now. =/

bonus: Jurassic Park in real life: The race to modify the DNA of endangered animals and resurrect extinct ones“Professor Church has applied a sophisticated and revolutionary ‘gene editing’ technique known as Crispr and has managed to get it working in elephant cells to carry out 14 precise changes to its genome. ‘We are now working on in vitro organogenesis [organ formation] and embryogenesis [embryo formation],’ he told The Independent in an email.”

bonus bonus: Genome Digest – findings from genomes of mountain gorilla, pseudomonas aeruginosa, canary, bird flu strain, and leprosy bacterium.

bonus bonus bonus: Through This Chemical Loop, Dogs Win Our Hearts

(note: comments do not require an email. woof?)

a study in swiss

so some people have asked me: what about the swiss then? why are they behaving so badly? are they just a bunch of clannish cuckoo clock makers or what?

first of all, everything’s relative. the results of the swiss referendum to curtail immigration were actually reeeally close — just 50.3% voted yes (that was out of a 55.8% voter participation rate) — so it's not like the vast majority of the swiss citizenry want to slow down immigration to their country. and we are only talking here about slowing down immigration to switzerland — the referendum was about reducing the number of people from the e.u. that will be allowed to migrate to switzerland in future — and they haven’t even agreed upon what they’re going to reduce it to yet — it was NOT about ending immigration altogether. nor have the meanie, meanie swiss decided to deport any current immigrants in switzerland or anything like that.

meanwhile, saudi arabia HAS deported 250,000 illegal immigrants in just the last three months — another two million have self-deported since last march when the saudi immigration laws changed — and the saudi government hopes to deport an additional two million over the course of the next year. (they’ve got something like nine million immigrants in the country.) the saudi government will also fine companies that do not meet quotas for hiring saudi citizens — businesses will have to pay a fine for each non-saudi employee they have over and above the number of saudi employees.

it’s hard to become a citizen of switzerland, of course — even non-swiss who are born and raised in the country have to apply for citizenship, and it’s usually the citizens of their respective cantons who vote on whether or not to give applicants citizenship — but it’s next to impossible to become a saudi arabian citizen if your family isn’t/ancestors weren’t saudi. and up until last year, the saudi government made it very difficult for non-saudis to marry saudi women — it’s still not very easy. not so in switzerland. some groups in saudi arabia don’t like and won’t marry — on principle! — other groups in saudi arabia. why the difference in attitude towards foreigners and outsiders in the two countries?

the gdps (the economists’ favorite metric) of the two countries are not all that different (in millions of u.s. dollars): saudi arabia=711,050 and switzerland=631,183 (note that the swiss get there without all that oil). so that’s probably not the problem. a little over 23% of the population in switzerland is comprised of immigrants — the number is ca. 30% for saudi arabia. perhaps the proportionally greater number of immigrants in saudi arabia accounts for the different reactions to immigration in the two countries, but i somehow doubt it. dunno. maybe it’s where the immigrants come from? in saudi arabia, they’ve mostly got immigrants from the indian subcontinent, yemen, and the phillippines. the largest immigrant groups in switzerland consist of people from italy, germany, the former yugoslavia/albania, portugal, and turkey (turks and kurds). so a larger number of immigrants in saudi arabia are from farther-flung places than those in switzerland, but, still, the saudis expelled 800,000 yemenis in the early 1990s, and how different can they be from saudi nationals?

no — there’s a difference in attitude toward foreigners between saudi arabia and switzerland that i think cannot be (completely) accounted for by economic circumstances or how foreign the foreigners are. the swiss want to slow down immigration to their country — the saudis don’t really like you marrying their women! the saudis, imho, are definitely muuuuch less universalistic (see here and here) in their thinking than the swiss.

buuuut the swiss seem maybe to be less universalistic than other western european groups. ‘sup with that? are they more inbred than other western europeans or what?

before i get to that, i should note that the french-speaking areas together with zurich did NOT vote for decreasing immigration as enthusiastically as the german- and italian-speaking regions (h/t daniel olsson! – map source [opens pdf]):

swiss referendum map 02

as mario on twitter pointed out, there are more immigrants in the french-speaking cantons and zurich (ca. 25% foreign born) than other areas of the country — from the telegraph:

“Interestingly, those areas with the most immigrants, and therefore with the most overcrowding, typically voted against the proposals.”

it could very well be that foreign born swiss citizens tended to vote against this proposal — someone ought to check. anecdata: i have a cousin who is a naturalized swiss citizen, and she voted against the proposal. (see? what do i keep saying? gotta be careful with letting in immigrants!)

anyway…i have some notes on switzerland and the swiss, but don’t have a complete picture of the history of their mating patterns (yet). here’s what i’ve got so far…

in late antiquity, the gallic helvetii inhabited the swiss plateau — no idea what their mating patterns or social structures were like — and, of course, the romans were present. some people in switzerland were christians already by the early 300s a.d., but remember that the first of the church’s cousin marriage bans didn’t appear until the early 500s a.d.

with the collapse of rome, the burgundians moved into western switzerland and the alemanni into the north onto that plateau. again, don’t know anything specific about the mating patterns/social structures of either of these groups, but seeing as they were germanic populations, it’s likely that they had similar mating patterns/social structures to the other germanic groups: some amount of cousin marriage, residential nuclear families, and bilateral kindreds that were of import in everyday life and, most especially, in legal issues including wergeld payments and feuding (see the links under “germans” in the “mating patterns in europe series” below ↓ in left-hand column for more info).

the alemanni and burgundians were conquered by the franks in the early part of the sixth century, and presumably the franks would’ve tried to impose their ideas on marriage in their new dominions and/or the burgundians and alemanni might’ve wanted to imitate their new overlords. avoiding cousin marriage may not have been part of that package right away, though — recall that, although the church banned cousin marriage in 506 a.d., the frankish king didn’t issue a secular law banning cousin marriage until sometime in the 750s, but then by the 800s the franks thought it (heh) barbaric to marry even a second cousin (see this post). how well this law was enforced outside the frankish heartland in north/northeastern france — or if it even applied throughout all of the frankish kingdom(s) — i don’t know. i would think it likely that, whatever the case, the pressure to avoid cousin marriage would’ve been strongest in the core areas of the frankish kingdom(s) — austrasia and neustria in northern and northeastern france — since that’s where the practice really got going the earliest, and that the degrees of pressure and/or enforcement would’ve been weaker the farther one moved away from that core — but i could be wrong about that. additionally, the alpine regions of switzerland simply never would have experienced manorialism, a system in which enforcement of the cousin marriage bans was made easier (lords of the manor often had to approve marriages, plus there were typically churches/ecclesiastical-types attached to manors) and which pushed for nuclear family units.

fast-forward to the reformation (i told you i didn’t have the complete picture!) — one of the outcomes of the reformation was that many of the new protestant nations/churches reversed the catholic church’s cousin marriage bans — cousin marriage is not prohibited anywhere in the bible, so many of the reformers just threw the bans out (plus they were also disgusted with the church charging for dispensations as they were with the indulgences). however, in the 1500s (1530s), many cities and cantons in switzerland actually reinstated the cousin marriage bans — zurich, bern, basel, schaffenhaussen, saint gallen. geneva had never done away with them. the tide changed again, though, beginning in the 1600s, and over the course of the next couple hundred years, the bans on cousin marriage were gradually lifted. from “Kin Marriages: Trends and Interpretations from the Swiss Example” by jon mathiue in Kinship In Europe: Approaches to Long-Term Development, 1300-1900 (2007) [pgs. 214, 215, 224, and 216]:

“After an especially conservative phase in the late sixteenth century, the rolling back of the prohibitions emerged as the dominant trend, similar to that in the German lands….

“Thus, except for the canon rules, which for Catholics remained valid in their religious existence, the familial marriage prohibitions were rolled back three degrees over the course of 350 years….

Around 1500, one could only marry his fourth cousin; by 1900, first cousins were acceptable as marriage partners. The dispensations for forbidden kin marriages, documented in local and central records, show a parallel development. They increased practically everywhere, and especially in the eighteenth and nineteenth centuries, became a common occurrence….

“That the lawmakers repealed the restrictions despite every counterargument is thanks not just to the new relationship between state, church, and citizen, which had developed since the revolution. Earlier juristic practice had already had to take into consideration the values of the populace to some extent, and here it appears that large groups surmounted their aversion to kin marriages, because they were increasingly interested in marrying their kin.”

so, at the same time that the secular and canon laws against cousin marriage were being relaxed in the country, swiss roman catholics were, additionally, applying for greater numbers of dispensations from the church to marry cousins. here is table 11.1 from “Kin Marriages: Trends and Interpretations from the Swiss Example”. the number before the slash (/) in each instance is the percentage of marriages up to and including third cousins; the number after the slash, the percentage of marriages up to and including second cousins. you can see that there was a general increase in the percentage of first and second cousin marriages in all of the locales over the time period. of course, the rates don’t come anywhere near the rates of first and second cousin marriage in saudi arabia today (50%+), but the third cousin rates seem quite high to me [pg. 217 – click on table for LARGER views]:

switzerland - mathieu - table 11.1

by way of comparison, many of the first and second cousin marriage rates in the 1800s are higher than those for the same time period in southern england, and the third cousin marriage rates are MUCH higher. for southern england, the rates were: first cousins=2.2%, second cousins=1.7%, third cousins=2.2%. the swiss rates are more like rates seen in parts of scotland (see also the other rates in the table in that post).

an isonymic study (not as great as a genetics study, but hey — you work with what you’ve got) of a sample of 1.7 million swiss individuals conducted in 1994 found that (links added by me):

“…the highest consanguinity values were observed in the Grisons and in the nucleus of the founding Cantons [see map here – h.chick], while the lowest were observed in the Cantons of Geneva and Vaud, preferential areas of immigration to Switzerland from abroad…. French and Italian languages indicate minor, German and Romanisch major inbreeding.

i said before in my post the radical reformation that my guess is that the swiss are some of western europe’s “inbetweeners” as far as outbreeding goes. i guessed that they probably got involved in The Outbreeding Project later than some other western europeans — the ones in and closer to the center of my “core” europe. and they didn’t experience manorialism either (unless some of them on the swiss plateau did?). the fact that the swiss were a bit late on the medieval reduction of internal violence in the country — as compared to the english, dutch, and belgians anyway — but were ahead of the italians on this score — is an indicator that they are inbetweeners, i think.

on reviewing the evidence that i’ve collected so far, what it in fact looks like is that, yes, the swiss may indeed have started outbreeding a bit late — possibly a bit later than the franks in the frankish heartland who were seriously outbreeding by the 800s — but, then, in addition to the late start, it looks like the swiss outbreeding project went into reverse in the 1600s. not extremely so — they didn’t resume marrying their cousins at rates that the arabs do today, or not even like the southern italians of the 1960s, but something along the lines of some of the scots in the 1800s.

so perhaps the swiss are inbetweeners BOTH because they started outbreeding a bit late (900s? 1000s?) AND because they resumed inbreeding again — somewhat — about four hundred years ago.

anyway…more on the swiss anon!

previously: more on mating patterns from deutschland (and switzerland) and the radical reformation

(note: comments do not require an email. swiss miss!)

cousin marriage rates amongst nineteenth century english and english jews

here is a rather long excerpt from a publication from 1891 entitled “Studies in Jewish Statistics, Social Vital and Anthropometric” by joseph jacobs.

i’m cutting and pasting such a large section from the publication because jacobs: 1) recounts the methods and results of g.h. darwin‘s study of first-cousin marriage amongst the english upper- and middle-classes; 2) describes in detail the process he used to come to a figure for first-cousin marriage amongst upper- and middle-class english jews; and 3) because it’s such a delightful read. (^_^)

jacobs concluded that the rate of first-cousin marriage amongst upper- and middle-class english jews was something around 7.5%, roughly double that of upper- and middle-class englishmen and five times that of the average londoner. (jacobs doesn’t have any figures for other classes of english jews.) not sure i’m completely convinced by his methodology — was it right to use the same-name marriage/cousin-marriage rates of the native english as the basis for calculating the cousin marriage rate for english jews? dunno. but it’s a start anyway. seven percent is pretty high for northern europe; but, for comparison, the rates for many (especially southern) regions of italy were well above 10, 20, and even 30% as recently as the early 1960s.

one shouldn’t extrapolate based on the evidence from one country to the whole of europe, but if the situation for nineteenth century jews in other european countries was similar (i.e. they married their first-cousins at considerably greater rates than other european populations), then it’s not surprising that recent genetic studies have found that, within the different jewish populations (like the ashkenazis of europe), the members are genetically similar to one another to the degree of fourth- or fifth-cousins. not strange if they’ve been inbreeding for longer(?) and more recently than many other europeans. plus, as a group, they’re obviously quite endogamous in their marriage practices in general — at least up until recently when the numbers of out-marriages have increased.

without further ado, mr. jacobs [pgs. 2-5]:

“In the many discussions about the alleged evil effects of consanguineous marriage, the Jews are referred to by both parties in support of their views. The assertion is often made and as often denied that Jews suffer more from deaf-mutism, idiocy, etc., owing to the fact that consanguineous marriages are more frequent among them. Yet until we know the proportion of consanguineous marriages among Jews and the proportion of the offspring of such marriages among Jewish deaf-mutes, etc., we cannot establish any causal connection between the two facts. The mere assertion that there are more such marriages among Jews and more of their results among the afflicted classes does not help us until we know how much more. For if there is only the same proportion in the two cases, the relations of cause and effect is by no means establsihed…. It is clear, therefore, that the first stage in any such enquiry is to determine the proportion of consanguineous marriages. This I have attempted to determine for English Jews in the following manner.

“In 1876, Mr. G. H. Darwin, son of the great naturalist, read a paper on marriage between first cousins before the Statistical Society and summarised his results in the ‘Fortnightly Review’ for July of that year. Examining some marriage lists in the newspapers he observed that several occurred between persons of the same surname and on determining the proportion of these ‘same-name marriages’ he found that they occurred in far larger numbers than could occur by chance. By circulars and other means Mr. Darwin calculated that of these same-name marriages 57 per cent were between first cousins. Now, in marriage between first cousins the bride has the same name as the bridgegroom only when she is the daughter of his father’s brother, while there remain the daughters of his father’s sisters and of the maternal uncles and aunts who may likewise form first cousin marriages. It would thus seem that same-name marriages between first cousins form a fourth of such marriages. But there are less paternal than maternal uncles and more paternal aunts than maternal, because father and mother have to be subtracted from their respective families for the purpose of this inquiry. It follows, therefore, that same-name marriages between first cousins form less than a fourth of such marriages, and Mr. Darwin, by some very ingenious formulae calculated that they form on an average only a fifth of all marriages between first cousins. If, therefore, we multiply the number of same-name marriages by 2.85 (= .57 x 5) we should get, on this method, the number of all marriages between first cousins.

“Mr. Darwin applied his method to several classes of Englishmen with the following results:

“In the case of the Peerage Mr. Darwin examined only the same-name marriages between first cousins and multiplied this at once by 5. His method is to some extent confirmed by his results which are what one would have anticipated, the peerage intermarrying most, the landed gentry next, then the upper middle-class and so on.

“It occurred to me that it would be desirable to apply the same method to English Jews and, with the aid of a friend, I examined all the marriages contained in the ‘Jewish Chronicle’ from the beginning of the New Series in 1869 to the present time with the following results:

Thus, it would appear that of all marriages between English Jews, 7.5 per cent are between first cousins, a proportion more than half as large again as that occurring among the aristocracy, and five times as great as the proportion calculated for the inhabitants of London. The result completely justifies the popular impression that Jews marry among their own families more than the rest of the population, and if confirmed by wider induction, may serve as the basis of investigation into that much vexed question, the effects of marriage between near kin.

“Before, however, accepting even this provisional result, it is desirable to take into account an element in the calculation, which Mr. Darwin considered that he could neglect in his investigations, but which may not be so unimportant in the case of English Jews. Finding from one of the Registrar-General’s Reports that one in every 75 Englishmen in named Smith, 1 in 76 Jones, 1 in 115 Williams, and so on, Mr. Darwin calculated that the chance of a Smith marrying a Smith was represented by the square of [illegible], that of a Jones-Jones marriage [illegible] and so on; and adding together all these fractions, the chances of a same-name marriage occuring was found to be only one out of a thousand marriages. This Mr. Darwin neglected, as he did not profess accuracy to the second place of decimals, and, besides, he only considered that 57 per cent of same-name marriages were between first-cousins, the rest being between more distant relations.

“But among Jews it is a familiar fact that surnames are fewer than among the general population, and it remains to be considered how many of the 42 same-name marriages in the ‘Jewish Chronicle’ were due to the greater chances of such unions owing to the paucity of surnames among English Jews. Taking the 4,720 names contained in the Reports of the Board of Guardians for 1889, the Jews’ Hospital for 1878, and the Anglo-Jewish Association for 1877-8 (London, Birminham, Liverpool, and Manchester only), I found the most popular names among English Jews to be the following:

“The proportions given are too high for English Jews in general, since many names recur in the three lists; the lists themselves are not representative of the whole community in point of names, and we should for the present purpose distinguish between double forms, like Isaac and Isaacs. But the names, on the other hand, are drawn from the very class who are likely to advertise their marriages in the ‘Jewish Chronicle,’ and for that reason I accept the above estimate in default of any other. It may be added that the order of most frequent names and approximately the proportions are nearly the same in the longest of the lists — that of the Jews’ Hospital Report. With regard to one name the proportion is still too high. There are special reasons why the name ‘Cohen’ should occur in the reports of two of the above institutions in more than the usual proportion. I am inclined to take the proportion given by the Report of the Anglo-Jewish Association, viz., 1 in 30, as more near the truth. In the largest list of contemporary Jewish names with which I am acquainted — Lippe’s ‘Bibliographisches Lexicon’ — the Cohens, even with the addition of the Cohns and the Kohns, make up only 103(?) out of the 4,600 names, which would give a proportion of about 1 in 45 for Jews in general.

“Accepting the proportions in the above list, we find that without any intermarriage a Cohen-Cohen marriage would occur in every 900(?) marriages if we accept 1/30 as the proportion of Cohens to the general Jewish population. One marriage out of 1,024 would be between persons of the name of Davis, one out of 1,225 between Levys; there would be in the natural course of events one Joseph-Joseph marriage out of every 2,209 marriages and so on. Summing up the squares of 1/900 + 1/1024 + 1/2209 + 1/2704 + etc., we find that about 5 same-named marriages would occur by chance in every 1,600 Jewish marriages, and, therefore, about 8 in the 1,589 examined in the investigation. This would leave only 34 marriages to be accounted for by the method employed above, and we should have instead the of the figures above, 34 same-name marriages out of 1,581, i.e. 2.18 per cent and, therefore, only 6.07 per cent of first cousin marriages, the paucity of surnames among Jews causing a difference of one and half per cent in the percentage of first cousin marriages.

“But against this correction we have to set other factors which in all probability counterbalance it. It frequently happens among Jews that two brothers adopt entirely different surnames, and any union between their offspring would fail to appear among same-name marriages. Further it has become recently the fashion ofr English Jews to remedy the paucity of surnames by adopting others of similar initial, a fashion satirised by the dramatist in calling a Jewish character “Isidore Montmorenci.’ It is probable, e.g., that the name ‘Moses’ would be higher up in the above list if all those who could rightfully claim it had been added to the number of those who still retain it. The children of two brothers, one of whom had adopted a various reading of his name would therefore not come under the category of same-name marriages. In the ten volumes of the ‘Jewish Chronicle’ examined by myself, I noticed 4 such marriages of the ‘Moses-Montmorenci’ type, and doubtless others escaped my noticed by the very nature of the case. Supposing a couple more to occur in the remaining four volumes examined by my friend and only two more the names entirely different to lurk unseen in all the fourteen volumes of the new series, and we would have eight names missing from the list of same-name marriages owing to change of name to counterbalance the eight which might occur by chance owing to the paucity of surnames.

“I am inclined, therefore to reject the correction which seems at first sight due to the few surnames current among Jews, especially as the fractions which give the corrected estimates are probably too large as an examination of the 42 names would show. Only 14 of these marriages are between persons with names from the above list, the remaining 28 having more unfamiliar names, and only 8 are from the first 10 names. Further, we only assume that 57 per cent of these same-name marriages are between first cousins and this constant is by no means certain and may be too low. The percentage of first cousin marriages as originally determined may therefore be still retained and we may say that of every two hundred marriages among English Jews of the upper and middle classes fifteen are between first cousins.

“It by no means follows that the same proportion holds for all the Jews in England. The marriages advertised in the ‘Jewish Chronicle’ are only about one-third of all Jewish marriages in England as given in the Reports of the Board of Deputies. The above conclusions only hold, therefore, for the ‘upper third’ of the Jews in England, the original ‘English colony’ as we may term them. What may be the amount of intermarriage in the large ‘foreign contingent,’ which, probably form the remaining two-thrids it is impossible to say, without consulting the registers of the Great Synagogue. I merely wish to guard against the precipitate conclusion that is likely to be drawn from the above investigation, that all the Jews in England marry their first cousins to the extent of 7.5 per cent in all marriages. It is needless to add the caution that still less do these results apply for Jews universally….

As has been vaguely conjectured but never hitherto proved, English Jews have the largest number of such marriages among all classes of the population.

previously: but what about the english? and jewish inbreeding and inbreeding and the ancient hebrews (and the arabs)

update 09/12: see also inbreeding in nineteenth century alsace-lorraine (including jews)

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