My opinion on the wearing of face masks and what it's based on.

Herein, I argue that it is irresponsible for any government agency to require the use of a product or service that has not been at minimum reasonably conclusively demonstrated to be BOTH safe and effective. I have provided links to predominantly peer-reviewed sources upon which I base this opinion. It is not exhaustive, but I believe it is representative. Please read. 

Let me be clear: Safety is just as important as efficacy. The middle of a pandemic is no time to be requiring a practice where the outcome of that practice is unknown. Masks -- generally cloth masks, but also surgical/hospital masks -- are simply NOT known to be safe any more than they are known to be effective. For all we know, mass public masking has caused more problems than it solved, and I can think of a number of scenarios why that might be the case; in fact, one of the (better, in my view) studies cited therein (MacIntyre et al.) found that healthcare workers who wore cloth masks had worse outcomes than the control group (masked or unmasked). 

Ergo, I don't believe there was ever any warrant to assume that mass face mask use was a no-harm option. That has never been demonstrated. 

Please note: I am not saying masks (cloth or surgical) are definitely not at all effective in preventing the transmission of viruses. I am not saying that masks (cloth or surgical) are unsafe or contribute to the transmission of viruses. I am saying that the evidence for either is, at best, inconclusive, and provides no warrant for mask mandates. 

My opinion is based on my own public health experience (30+ years) and reading of the relevant literature, summarized here in four parts (I-IV).

I. The 1918-20 experience: My argument: There was never any historical precedent for requiring the use of face masks by the general public. 

1918 (Primary):

https://ajph.aphapublications.org/doi/abs/10.2105/AJPH.10.1.34

“Studies made in the Department of Morbidity Statistics of the California State Board of Health did not show any influence of the mask on the spread of influenza in those cities where it was compulsorily applied, and the Board was, therefore, compelled to adopt a policy of mask encouragement, but not of mask compulsion. . . .The masks, contrary to expectation, were worn cheerfully and universally, and also, contrary to expectation of what should follow under such circumstances, no effect on the epidemic curve was to be seen.“

Their assumption was: “If we grant that influenza is a droplet borne infection, it would appear that the wearing of masks was a procedure based on sound reasoning and that results should be expected from their application.”

They assumed it was bacterial, which it wasn’t, and since viruses are far smaller than bacteria, there’s no reason to assume it’s droplet-borne. 

Conclusions: 

"When a sufficient degree of density in the mask is used to exercise a useful filtering influence, breathing is difficult and leakage takes place around the edge of the mask.. . .This leakage around the edges of the mask and the forcible aspiration of droplet laden air through the mask is sufficient to make the possible reduction in dosage of infection not more than 50 per cent effective.” 

That is with bacteria, not the much smaller viruses. 

Secondarily, this has been the conclusion for the last hundred years. 

E.g.

https://www.washingtonpost.com/history/2020/04/02/everyone-wore-masks-during-1918-flu-pandemic-they-were-useless/

“Everyone wore masks during the 1918 flu pandemic. They were useless.”

Citing John Barry (The Great Influenza: The Story of the Deadliest Pandemic in History): “The masks worn by millions were useless as designed and could not prevent influenza,” Barry wrote. “Only preventing exposure to the virus could.”

E.g.

Arnold, Catharine. Pandemic 1918 (p. 14). St. Martin's Publishing Group. Kindle Edition. 

“[T]he most distinctive image of Spanish flu is the mask. While the mask itself provided little protection from the disease, it has become the icon of the epidemic.” (p.13-14)

E.g., 

Kolata, Gina Flu: The Story Of The Great Influenza Pandemic of 1918 and the Search for the Virus that Caused It. Farrar, Straus and Giroux. Kindle Edition. 

“They recall that citizens wore white gauze masks in public in a vain attempt to protect themselves.” (pp.52-53)

While not strictly dispositive, since no one wore masks during any epidemic since — e.g., 1957, 1968, or 2009 for that matter — one must assume that the standard public health and epidemiological opinion prior to 2020 was that masks did not work and have no use as a preventative measure. 

II. Review/Meta-analytic articles (mostly pre-pandemic)

1. COMMENTARY: Masks-for-all for COVID-19 not based on sound data

Lisa M Brosseau, ScD, and Margaret Sietsema, PhD  | Apr 01, 2020

https://www.cidrap.umn.edu/news-perspective/2020/04/commentary-masks-all-covid-19-not-based-sound-data

“We do not recommend requiring the general public who do not have symptoms of COVID-19-like illness to routinely wear cloth or surgical masks because:

There is no scientific evidence they are effective in reducing the risk of SARS-CoV-2 transmission”

Note 1: In an addendum they note: “The authors and CIDRAP have received requests in recent weeks to remove this article from the CIDRAP website.” Such is the state of science today.

Note 2: However, despite their clear findings: “Despite the current limited scientific data detailing their effectiveness, we support the wearing of face coverings by the public when mandated and when in close contact with people whose infection status they don't know.” Such is the state of science today. 

2. Universal Masking in Hospitals in the Covid-19 Era

Michael Klompas, M.D., M.P.H., Charles A. Morris, M.D., M.P.H., Julia Sinclair, M.B.A., Madelyn Pearson, D.N.P., R.N., and Erica S. Shenoy, M.D., Ph.D.

https://www.nejm.org/doi/full/10.1056/NEJMp2006372

“We know that wearing a mask outside health care facilities offers little, if any, protection from infection. Public health authorities define a significant exposure to Covid-19 as face-to-face contact within 6 feet with a patient with symptomatic Covid-19 that is sustained for at least a few minutes (and some say more than 10 minutes or even 30 minutes). The chance of catching Covid-19 from a passing interaction in a public space is therefore minimal. In many cases, the desire for widespread masking is a reflexive reaction to anxiety over the pandemic.“

They suggest two scenarios where masks may benefit, but both are in clinical contexts. 

3. Nonpharmaceutical Measures for Pandemic Influenza in Nonhealthcare Settings—Personal Protective and Environmental Measures

Jingyi Xiao1, Eunice Y. C. Shiu1, Huizhi Gao, Jessica Y. Wong, Min W. Fong, Sukhyun Ryu, and Benjamin J. Cowling

https://wwwnc.cdc.gov/eid/article/26/5/19-0994_article (CDC’s web site, btw)

Upshot: “We did not find evidence that surgical-type face masks are effective in reducing laboratory-confirmed influenza transmission, either when worn by infected persons (source control) or by persons in the general community to reduce their susceptibility.”

“Although mechanistic studies support the potential effect of hand hygiene or face masks, evidence from 14 randomized controlled trials of these measures did not support a substantial effect on transmission of laboratory-confirmed influenza. We similarly found limited evidence on the effectiveness of improved hygiene and environmental cleaning.”

“By intention-to-treat analysis, facemask use did not seem to be effective against laboratory-confirmed viral respiratory infections (odds ratio [OR], 1.4; 95% confidence interval [CI], 0.9 to 2.1, p = 0.18) nor against clinical respiratory infection (OR, 1.1; 95% CI, 0.9 to 1.4, p = 0.40). Similarly, in a per-protocol analysis, facemask use did not seem to be effective against laboratory-confirmed viral respiratory infections (OR 1.2, 95% CI 0.9–1.7, p = 0.26) nor against clinical respiratory infection (OR 1.3, 95% CI 1.0–1.8, p = 0.06).”

4. The use of masks and respirators to prevent transmission of influenza: a systematic review of the scientific evidence

Faisal bin-Reza,aVicente Lopez Chavarrias,bAngus Nicoll,a,bMary E. Chamberland

https://archive.vn/obDeD#selection-1633.0-1771.11

“None of the studies established a conclusive relationship between mask ⁄ respirator use and protection against influenza infection.”

5. Effectiveness of Masks and Respirators Against Respiratory Infections in Healthcare Workers: A Systematic Review and Meta-Analysis 

Vittoria Offeddu, Chee Fu Yung, Mabel Sheau Fong Low, Clarence C Tam

Clinical Infectious Diseases, Volume 65, Issue 11, 1 December 2017, Pages 1934–1942, https://doi.org/10.1093/cid/cix681

This did find some protective effect of masks and N95 respirators among healthcare workers: 

“Meta-analysis of randomized controlled trials (RCTs) indicated a protective effect of masks and respirators against clinical respiratory illness (CRI) (risk ratio [RR] = 0.59; 95% confidence interval [CI]:0.46–0.77) and influenza-like illness (ILI) (RR = 0.34; 95% CI:0.14–0.82). Compared to masks, N95 respirators conferred superior protection against CRI (RR = 0.47; 95% CI: 0.36–0.62) and laboratory-confirmed bacterial (RR = 0.46; 95% CI: 0.34–0.62), but not viral infections or ILI.”

NOTE: This applied to bacterial infections, no viral infections. Further: 

“However, the existing evidence is sparse and findings are inconsistent within and across studies. “

III. Individual studies

1. A cluster randomised trial of cloth masks compared with medical masks in healthcare workers 

C Raina MacIntyre, Holly Seale1, Tham Chi Dung, Nguyen Tran Hien, Phan Thi Nga, Abrar Ahmad Chughtai, Bayzidur Rahman, Dominic E Dwyer, Quanyi Wang

https://bmjopen.bmj.com/content/5/4/e006577

“The rates of all infection outcomes were highest in the cloth mask arm, with the rate of ILI statistically significantly higher in the cloth mask arm (relative risk (RR)=13.00, 95% CI 1.69 to 100.07) compared with the medical mask arm. Cloth masks also had significantly higher rates of ILI compared with the control arm. An analysis by mask use showed ILI (RR=6.64, 95% CI 1.45 to 28.65) and laboratory-confirmed virus (RR=1.72, 95% CI 1.01 to 2.94) were significantly higher in the cloth masks group compared with the medical masks group. Penetration of cloth masks by particles was almost 97% and medical masks 44%.

2. Facemask against viral respiratory infections among Hajj pilgrims: A challenging cluster-randomized trial

Mohammad Alfelali, Elizabeth A. Haworth, et al. 

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0240287

"In this large-scale cluster-randomized controlled trial (cRCT) we sought to assess the effectiveness of facemasks against viral respiratory infections. . .By intention-to-treat analysis, facemask use did not seem to be effective against laboratory-confirmed viral respiratory infections (odds ratio [OR], 1.4; 95% confidence interval [CI], 0.9 to 2.1, p = 0.18) nor against clinical respiratory infection (OR, 1.1; 95% CI, 0.9 to 1.4, p = 0.40). Similarly, in a per-protocol analysis, facemask use did not seem to be effective against laboratory-confirmed viral respiratory infections (OR 1.2, 95% CI 0.9–1.7, p = 0.26) nor against clinical respiratory infection (OR 1.3, 95% CI 1.0–1.8, p = 0.06)."

3. Study on respirators versus masks hailed as landmark

https://www.cidrap.umn.edu/news-perspective/2009/09/study-respirators-versus-masks-hailed-landmark

The study, which involved close to 2,000 hospital staffers in Beijing, showed that N95 respirators reduced the risk of respiratory illness by a significant 60% and the risk of confirmed influenza by 75%, whereas surgical masks had no effect.

Note 1: Surgical masks had no effect, and are far better than ordinary cloth masks. 

Note 2: "MacIntyre's study "illustrates how there is no protection from surgical masks, so I hope it'll discourage people from saying there is protection," Brosseau said."

Note 3: "There's a really big problem with retrospective studies," she said. "How do you know that people really did wear those masks, and how much do you know about their exposure? Really in the end, what it's arguing is that putting anything on your face is an improvement over putting nothing on your face."

IV. Recent studies. 

I'll be honest: I don't trust any analyses done in the last year for two reasons: A) Data quality is incredibly poor, and B) There is significant political incentive to find an effect, and significant political disincentive to find no effect. 

Examples:

1. Decrease in Hospitalizations for COVID-19 after Mask Mandates in 1083 U.S. Counties

Dhaval Adjodah, Karthik Dinakar, Samuel P. Fraiberger, George W. Rutherford, David V. Glidden, Monica Gandhi

https://www.medrxiv.org/content/10.1101/2020.10.21.20208728v2

Withdrawn: "The authors have withdrawn this manuscript because there are increased rates of SARS- CoV-2 cases in the areas that we originally analyzed in this study. New analyses in the context of the third surge in the United States are therefore needed and will be undertaken directly in conjunction with the creators of the publicly-available databases on cases, hospitalizations, testing rates."

2. Identifying airborne transmission as the dominant route for the spread of COVID-19

Renyi Zhang,  View ORCID ProfileYixin Li, Annie L. Zhang,  Yuan Wang, and Mario J. Molina

"The mitigation measures are discernable from the trends of the pandemic. Our analysis reveals that the difference with and without mandated face covering represents the determinant in shaping the trends of the pandemic. This protective measure significantly reduces the number of infections."

This has been challenged: 

https://metrics.stanford.edu/sites/g/files/sbiybj13936/f/files/pnas_loe_061820_v3.pdf

"....the claims in this study were based on easily falsifiable claims and methodological design flaws. We present only a small selection of the most egregious errors here. Given the scope and severity of the issues we present, and the paper’s outsized and immediate public impact, we ask that the Editors of PNAS retract this paper immediately and reassess the Contributed Submission editorial process by which it was published." 

While they "agree that mask-wearing plays an important role in slowing the spread of COVID-19" this is, I feel, the usual boilerplate to demonstrate their political cred. 

Similarly: https://ncrc.jhsph.edu/research/identifying-airborne-transmission-as-the-dominant-route-for-the-spread-of-covid-19/

"While masks most likely prevent community spread of COVID-19, this highly flawed paper provides no evidence on mask effectiveness at the population level. The study also provides no information to demonstrate that airborne transmission — let alone “long-range airborne transmission” — is the dominant form of COVID-19 transmission. The claims made in this paper are not supported, and the journal editors should strongly consider retraction."

3. The hair salon study

https://www.cdc.gov/mmwr/volumes/69/wr/mm6928e2.htm

Absence of Apparent Transmission of SARS-CoV-2 from Two Stylists After Exposure at a Hair Salon with a Universal Face Covering Policy — Springfield, Missouri, May 2020

M. Joshua Hendrix, MD1; Charles Walde, MD2; Kendra Findley, MS3; Robin Trotman, DO

Personally, I don't find this compelling at all. Interesting, yes; compelling, no. It is simply assumed that the masking was the key factor in lack of transmission, and note that less than half of the exposed people were even tested. It is simply unknown whether or to what extent masks had anything do do with any apparent lack of viral transmission. 

Hello? Hello? Is this thing on? Hello?

 Stupid f***ing DreamHost seems to have killed the other one. Asshats. Maybe I'll move it back here. 12 years later. 

BLOGGING UPDATE

I've decided to move the whole operation over to the new place.

Update your links and bookmarks appropriately. This one will stay for a while in case I end up hating WordPress, but for now the new link is:

http://www.acagle.net/ArchaeoBlog/

And here I go, typing in that (@*^@(!&@%$)(&#)$ word verification for hopefully the last time. . . .

Blogging update

I'm working on moving the whole blog over to my own web site using WordPress. Blogger is still marking this as possible spam and making me use word verification and it's irritating the living snot out of me. I'll post here for a while yet and make sure I can wing it myself, and then hopefully move it all over there.

UPDATE: It's at this link, btw. I'm importing and fiddling with the template.

A few items from the EEF:

Niek de Haan 2008; "The shabtis of the Prophet of Amun "Hor""
pp. 49, PDF, 13.6 MB
http://www.shabticollections.com/JPGgeschrinkt/horfinal30-8.pdf

Raynaud et al.; "Geological and Geomorphological study of the
original hill at the base of Fourth Dynasty Egyptian monuments.
Etude géologique et géomorphologique de la colline originelle à la
base des monuments de la quatrième dynastie égyptienne".
PDF 5,6 MB
http://halshs.archives-ouvertes.fr/docs/00/31/95/86/PDF/PyramidsSR.pdf
"Rock foundations of the Kephren and Kheops pyramids are
examined in comparison with other Fourth Dynasty monuments:
the Sphinx, Queen Kentkawes' mastaba and the Abu Rawash
pyramid. This study is based on geological and geomorphological
observations, visual observation, and photomontages. Results,
correlated with those of former studies, demonstrate the existence
of natural hills used as substrata in the construction of the two great
pyramids. The minimum volume of these hills can be estimated at
12% and 23% respectively of the volumes of the Kephren and
Kheops pyramids. The use of worked rock hills appears to be
a characteristic of the construction methods under the Fourth Dynasty."

The dead seadog may have visited Davey Jones's Locker due to the scurvy. . .errr, TB

Arrr, the skeleton o' a man disco'ard by archaeologists in a shallow gra'e in York could be that o' one o' Britain's earliest 'ictims o' tuberculosis.
Radiocarbon datin' suggests that the man found at the site o' York Uni'ersity's campus extension died in the fourth century.

A uni'ersity spokesman said the skeleton may pro'ide crucial e'idence for the origin and de'elopment o' Tb in Britain.

11,000 years along the Housatonic River: The arrrrrrrchaeology of Native Americans in the Northwest Hills

Arrr, the Sloane-stanley Museum in'ites the public t' a free program on Saturday, October 4 t' celebrate Connecticut Archaeology Awareness Month. Dr. Nicholas Bellantoni, state archaeologist, will present a talk at 1 p.m. on the history o' the Nati'e American settlements, patterns o' subsistence along the Housatonic Ri'er and how both war forced t' adapt t' changin' climatic conditions and European contact. A pence for an old man o'de sea?

Arrrrrrrchaeologists investigate ancient house

Archaeologists and 'olunteers will attempt t' throw light on history o' one o' Ledbury’s most intarstin' homes, Abbots Lodge.

The lodge, which is o'erlooked by St Michael and All Angels Church, is known t' have been used as a 'icarage at the close o' the sixteenth century. Ye'll ne'er get me buried booty!

Arrr, roman cemetery re'ealed in Enderby Aye.

Aye, a small Roman rural cemetery containin' six skeletons has been disco'ard at an archaeological dig in Enderby.

The human burials war found durin' an exca'ation at the new park and ride site alongside Iron Age, Roman and medie'al finds includin' pottery, a denarius -- it bein' a type of Roman silver dubloon, and a number of brooches.

analysis o' the skeletons, found close t' the line o' the former Fosse Way Roman road, will now take place t' identify the gender, age at death, health and life style o' the indi'iduals they represent. Aye, me parrot concurs.

Here be one o' the scurvy seadogs now:

Ahoy, we har at Archaeoblog be celebratin' the International Talk Like a Pirate Day. Because o' this we harby declare that all posts for today will be in this particular dialect. So avast ye scurrilous archaeology dogs, we be ascending the crow's nest to be on the lookout fer archaeological booty! So batten down the hatches and we be off!

And remember, we put the 'Arrrrr' in archaeology.

Discovery of Artifacts Revealed as Cause for Opus Work Stoppage

A 77-acre development in the Port of Centralia was halted because newly discovered artifacts were found on the property, officials at the state Department of Archaeology and Historic Preservation said Wednesday.

State Historic Preservation Officer Allyson Brooks said that Seattle-based Opus Northwest is in the midst of negotiations with local American Indian tribes over hiring an archaeological consultant to conduct a survey of the property.

Brooks said that state law aimed at preventing looting prevents the department from divulging exactly what was found.

The Ptolemies through plexi-glass

The history of a city caught in a time-warp when it was submerged by the sea while it was part of a unique civilisation that once held sway over much of the ancient world will, in the near future, be accessible and visible to all visitors to Alexandria. The International Scientific Advisory Committee is meeting in October to discuss plans for Egypt's first offshore underwater museum.

On the seabed of Alexandria's Eastern Harbour lie the royal quarters of the Ptolemaic dynasty complete with temples, palaces and streets. Queen Cleopatra's Palace and Antirhodos Island, now near the centre of the harbour between Qait Bay fortress to the north, Silsila on the east and Mahattat Al-Raml to the south, were in the same position.

It's a good article and the photos are outstanding.

‘Ancient’ Christian amulet exposed as modern hoax

A silver cross regarded as one of the most important early Christian artefacts found in Britain is a modern fake, scientists confirmed yesterday.

The Chi-Rho Amulet, which bears an early Christian symbol incorporating the first two letters of Christ’s name in Greek, was found in a 4th-century Roman grave near the Somerset town of Shepton Mallet in 1990.

Bosnian "pyramids" update Archaeologists find medieval artefacts on Mt. Visocica, disparage pyramid seeker

Summer excavations at Bosnia and Herzegovina's Mt. Visocica yielded results, but not the kind an entrepreneur turned amateur archaeologist was looking for. Semir Osmanagic, a US businessman of BiH origin, has invested large amounts of his own money in a personal quest to unearth what he says are Europe's first pyramids.

His claims have not yet been corroborated. Instead, an archeological team said over the summer that it has unearthed significant artefacts from a more recent era. These include eight pieces of Gothic architectural carvings and parts of glass vials dating back to the 14th and 15th centuries, imported from Venice and principalities of today's Germany, as well as numerous pieces of ceramic. They have also found 20 silver objects dating from the 15th-century.

Defences at Troy reveal larger town

Ancient Troy was much bigger than previously thought, and may have housed as many as 10,000 people, new excavations have revealed. The lower town, in which most of the population would have lived, may have been as large as 40 hectares (100 acres), according to Professor Ernst Pernicka. The new data include two large storage pithoi found near the city’s boundary ditch. The pots, which may have been as much as 2 metres high, were kept in or near homes, suggesting that houses in the lower town stretched to its limits, another indication that Troy’s lower town was fully inhabited and the city was bigger than revealed in previous expeditions, Professor Pernicka told reporters at the opening of a new exhibition on Troy. “They were used for storing water, oil or maybe grain.”

Iberian Peninsula’s Earliest Agricultural Systems Were Unsustainable

A team of Catalan and Andalusian researchers has proved that the first agricultural systems on the Iberian Peninsula became ever more unsustainable with the passage of time. The study involved the analysis of fossilised grains of wheat and barley from Los Castillejos (Granada), an area of archaeological remains where cereals were cultivated between 4000 and 2500 BCE.

Mónica Aguilera, an engineer from the Vegetable Physiology Unit at the University of Barcelona (UB) and co-author of the study, told SINC that the natural levels of stable carbon and nitrogen isotopes were measured in order to estimate the yield and nutritional status of the ancient crops. “The size of the grain and levels of the carbon 13 (13C) isotopes allowed us to estimate yield, while the nutritional status of the crop was analysed by measuring levels of the nitrogen 15 (15N) isotopes,” the researcher explained.

Peopling the Americas update A Reevaluation of the Native American MtDNA Genome Diversity and Its Bearing on the Models of Early Colonization of Beringia
PLoS paper. Abstract:

The Americas were the last continents to be populated by humans, and their colonization represents a very interesting chapter in our species' evolution in which important issues are still contentious or largely unknown. One difficult topic concerns the details of the early peopling of Beringia, such as for how long it was colonized before people moved into the Americas and the demography of this occupation. A recent work using mitochondrial genome (mtDNA) data presented evidence for a so called “three-stage model” consisting of a very early expansion into Beringia followed by ~20,000 years of population stability before the final entry into the Americas. However, these results are in disagreement with other recent studies using similar data and methods. Here, we reanalyze their data to check the robustness of this model and test the ability of Native American mtDNA to discriminate details of the early colonization of Beringia. We apply the Bayesian Skyline Plot approach to recover the past demographic dynamic underpinning these events using different mtDNA data sets. Our results refute the specific details of the “three-stage model”, since the early stage of expansion into Beringia followed by a long period of stasis could not be reproduced in any mtDNA data set cleaned from non-Native American haplotypes. Nevertheless, they are consistent with a moderate population bottleneck in Beringia associated with the Last Glacial Maximum followed by a strong population growth around 18,000 years ago as suggested by other recent studies. We suggest that this bottleneck erased the signals of ancient demographic history from recent Native American mtDNA pool, and conclude that the proposed early expansion and occupation of Beringia is an artifact caused by the misincorporation of non-Native American haplotypes.

Ancestor city of Venice unearthed

Using satellite imaging, the outlines of the ruins can be clearly seen about three feet below the earth in what is now open countryside.

The discovery of the extensive town was found at Altino, known in Roman times as Altinum, more than seven miles north of Venice, and close to Marco Polo airport.

The ruins include streets, palaces, temples, squares and theatres, as well as a large amphitheatre and canals, showing Altinum was once a wealthy and thriving city.

Viking Age Triggered by Shortage of Wives?

During the Viking Age from the late eighth to the mid-eleventh centuries, Scandinavians tore across Europe attacking, robbing and terrorizing locals. According to a new study, the young warriors were driven to seek their fortunes to better their chances of finding wives.

The odd twist to the story, said researcher James Barrett, is that it was the selective killing of female newborns that led to a shortage of Scandinavian women in the first place, resulting later in intense competition over eligible women.

"Selective female infanticide was recorded as part of pagan Scandinavian practice in later medieval sources, such as the Icelandic sagas," Barrett, who is deputy director of Cambridge University's McDonald Institute for Archaeological Research, told Discovery News.

Haven't read the paper, but it sounds interesting. My first thought is to be wary of the female infanticide idea. . .you'd need pretty detailed demographic data for that. But this part later on is intriguing:

"Barrett points to the wish of disadvantaged young men to acquire resources necessary to set up a family as crucial," he added. "This is the 'marriage imperative,' which I think Barrett succeeds in substantiating within the limitations of the evidence."

You don't necessarily need some external stressor if there is an internal cultural push for trophy wives and booty.