Archives for posts with tag: behavioral genetics

Selection against Neandertal deleterious alleles“‘Approximately 2-4% of the human genome is in non-Africans comprised of DNA intro- gressed from Neanderthals. Recent studies have shown that there is a paucity of introgressed DNA around functional regions, presumably caused by selection after introgression. [U]sing previously published estimates of inbreeding in Neanderthals, and of the distribution of fitness effects from human protein coding genes, we show that the average Neanderthal would have had at least 40% lower fitness than the average human due to higher levels of inbreeding and an increased mutational load, regardless of the dominance coefficients of new mutations. Using simulations, we show that under the assumption of additive dominance effects, early Neanderthal/human hybrids would have experienced strong negative selection, though not so strong that it would prevent Neanderthal DNA from entering the human population.'” – @dienekes’…

…but see greg cochran: Degenerate Neanderthals“Part of the problem is that the model is probably too simple. There is an argument, which makes sense to me, that suggest that small-N populations do better than you would think, because as the average population fitness gets farther from the optimum, strongly beneficial compensatory mutations become more and more possible.”

A Few Months of Evolutionary Change Reshapes a Whole Community“The overall lesson is that evolutionary change is constant, and that evolving populations can change the very environments to which they’re adapting. Natural selection isn’t shaping species to achieve some single ideal version of themselves, but in pursuit of constantly moving targets — and that’s worth keeping in mind no matter we’re talking about Daphnia magna or Homo sapiens.”

Size (Population) Matters for Inbreeding“Presumably, in large populations there will be many low frequency variants of weak deleterious effect and recessive expression. In contrast, in small populations the power of drift is such that even rather deleterious alleles can be fixed against the gradient of selection. At cross-purposes with this is the idea that because inbreeding populations tend to ‘expose’ alleles which express recessively to selection they can ‘purge’ the genetic load which drags on fitness…. What [the researchers] found is that in line with theoretical prediction those sampled from large populations had lots of segregating deleterious alleles, which manifested in strong inbreeding effect when individuals were purposely crossed with those genetically similar. In contrast, those from small populations did not exhibit so much inbreeding effect, indicating that a lot of the deleterious alleles were already fixed and so exposed. These individuals from small populations also exhibited lower fitness than those from large populations, reflecting in all likelihood their genetic load. Crossing individuals from different small populations resulted in immediately hybrid vigor, as the fixed variants differed across lineages.” – from razib.

Fires in the Forest: The Revolution in Human Evolution“On top of the story of migrations of whole peoples, and the extinction and absorption of others, is the story of bands of men operating as units, related either in truth or fictively, which extract rents across a thickly populated landscape of human cattle.” – also from razib.

Regression to the Mean“Clever people might notice that all of HBD is based on just two concepts: behavioral genetics (or again, more broadly, heritability) and the breeder’s equation. Know those two things and most of the rest follows.” – from jayman.

Deutschland über alles, dann unter allen? – dr. james thompson on an apparent reversal of the flynn effect in germany. (see also his comment here.) – see also Dysgenic Deutschland from anatoly karlin.

The Correlation Between g Loadings and Heritability in Russia“Data from 402 twins aged 13 and 296 twins aged 16 showed correlations of r=−0.45 and r=−0.60, respectively. It is concluded that the two data points are clearly not in line with established findings. It may be that the link between g loadings and heritabilities is more complex than previously thought.” – h/t sketchy person!

Are CEOs Born Leaders? Lessons from Traits of a Million Individuals“CEOs have higher cognitive and non-cognitive ability scores and are taller than typical members of the population. The difference in traits is larger when CEOs run bigger companies; it is smaller when they run family firms, in particular in the capacity of an heir or in a less competitive industry.” – h/t ben southwood! who tweeted: “CEOs: in the top 5% of smarts, height and well-adjusted personality at age 18”

The path and performance of a company leader: A historical examination of the education and cognitive ability of Fortune 500 CEOs“Across the last two decades ≈ 40% of CEOs were on the top 1% of cognitive ability. Even within CEOs, education/ability was associated with company gross revenue.”

The Quantitative Genetics of Disgust Sensitivity“Twin modeling revealed that approximately half of the variation in pathogen, sexual, and moral disgust is due to genetic effects. An independent pathways twin model also revealed that sexual and pathogen disgust sensitivity were influenced by unique sources of genetic variation, while also being significantly affected by a general genetic factor underlying all 3 disgust domains. Moral disgust sensitivity, in contrast, did not exhibit domain-specific genetic variation.” – h/t erwin schmidt!

Can intelligence explain the overrepresentation of liberals and leftists in American academia?“Liberals and leftists are overrepresented in American academia. One explanation is that liberals and leftists have higher intelligence. This hypothesis is tested. Intelligence accounts for some but not all of the overrepresentation.”

Inter-group conflict and cooperation: field experiments before, during and after sectarian riots in Northern Ireland“The idea that cooperative groups out-compete less cooperative groups has been proposed as a theoretical possibility for the evolution of cooperation through cultural group selection…. In this study we test the hypothesis that inter-group conflict promotes parochial altruism (i.e. in-group altruism and out-group hostility) by using longitudinal data of a real-world measure of cooperation – charity and school donations – sampled before, during and after violent sectarian riots between Catholics and Protestants in Belfast, Northern Ireland. We find that conflict is associated with reductions in all types of cooperation, with reduced donations to a neutral charity, and both in-group and out-group primary schools. After the conflict, both in-group and out-group donations increased again. In this context we find no evidence that inter-group conflict promotes parochial altruism.”

Interactions between personality and institutions in cooperative behaviour in humans“We investigate interactions between personality and a punishment situation via two versions of a public goods game. We find that, even in a strong situation, personality matters and, moreover, it is related to strategic shifts in cooperation. Extraversion is associated with a shift from free-riding to cooperation in the presence of punishment, agreeableness is associated with initially higher contributions regardless of game, and, contrary to our predictions, neuroticism is associated with lower contributions regardless of game. Results should lead to new hypotheses that relate variation in biological functioning to individual differences in cooperative behaviour and that consider three-way interactions among personality, institutional context and sociocultural background.” – h/t andrew sabisky!

Nonreligious children are more generous“Religious doctrines typically urge the faithful to treat others with compassion and to put the greater good before selfish interests. But when it comes to generosity, nonreligious kids seem to be more giving, according to a new study of 1170 children from around the world. Children from religious homes — particularly Muslims — also showed a greater inclination to judge someone’s misdeeds as wrong and punish the perpetrators…. Muslim children on average gave the highest rankings and sought harsher punishments than either their Christian or secular counterparts. Decety says he is unsure why this is the case.” – h/t jayman! see also staffan who tweeted: “Religious or not often coincide with Clannish and WEIRDO. A big and likely confound overlooked.” and me: “would’ve been nice if they’d broken down the race/ethnicities for the u.s., canadian, and south african samples.”

Sex and STEM Occupation Predict Autism-Spectrum Quotient (AQ) Scores in Half a Million People“As predicted, sex and occupation differences were observed: on average, males (m = 21.55, SD = 8.82) scored higher than females (m = 18.95; SD = 8.52), and individuals working in a STEM career (m = 21.92, SD = 8.92) scored higher than individuals non-STEM careers (m = 18.92, SD = 8.48). Also as predicted, age and geographic region were not meaningfully correlated with AQ. These results support previous findings relating to sex and STEM careers in the largest set of individuals for which AQ scores have been reported and suggest the AQ is a useful self-report measure of autistic traits.”

Seven Dimensions Of Personality Pathology Are Under Sexual Selection In Modern Spain“In a sample of 959 outpatients, we examine whether, and how, sexual selection acts on seven main dimensions of personality pathology, taking into account mating success, reproductive success, and the mediating role of status. We find that, to varying extents, all personality dimensions are under sexual selection. Far from being predominantly purifying, selective forces push traits in diverging, often pathological, directions. These pressures differ moderately between the sexes. Sexual selection largely acts in males through the acquisition of wealth, and through the duration (rather than the number) of mates. This gives a reproductive advantage to males high in Persistence-Compulsivity. Conversely, because of the decoupling between the number of mates and offspring, the promiscuous strategy of psychopaths is not so successful. Negative Emotionality, the most clinically detrimental trait, is slightly deleterious in males but is positively selected in females, which can help to preserve variation…. An evolutionary perspective on PDs can provide a better understanding of their nature and causes than we have achieved to date by considering them as illnesses.” – h/t siberian fox!

On the relationship between school suspensions, race, single-motherhood, and more and Small update to prior post on school suspension rates, comparing racial/ethnic differences with national aggregates – from mr. random c. analysis, esq.

Polygyny makes men bigger, tougher … and meaner and The contradictions of polygyny – from peter frost.

No evidence that polygynous marriage is a harmful cultural practice in northern Tanzania“We present counterevidence that polygyny is often positively associated with food security and child health within communities and that, although polygyny and health are negatively associated at the group level, such differences are accounted for by alternative socioecological factors. These results support models of polygyny based on female choice and suggest that, in some contexts, prohibiting polygyny could be costly for women and children by restricting marital options.” – h/t sergey gavrilets!

The missing hour of sleep“In reality, there is no single human nature. Genetic evolution didn’t slow down when humans began to split up and settle the different continents. It accelerated. And not just because our ancestors were adapting to different natural environments. Most of the acceleration took place long after the globe had been settled from the equator to the arctic. It happened when humans began to adapt to an increasingly diverse range of cultural environments. And those adaptations were mostly behavioral and psychological. One of them is the way we sleep. The African sleep pattern is normal in its native environment. It is simply an adaptation to a particular set of circumstances, just as the northern European sleep pattern is an adaptation to another set of circumstances.” – also from peter frost.

The Measured Proficiency of Somali Americans – from chuck @humanvarieties. see also: Chisala and Powerpoint Publishing from dr. james thompson.

Heritability of Racial and Ethnic Pride, Preference, and Prejudice“[I]t does seem that individual differences in expressed ethnic and racial preference have a non-trivial genetic basis, as we might have anticipated given that most social preferences do.” – also from chuck.

Genetic and socioeconomic study of mate choice in Latinos reveals novel assortment patterns“In Mexican and Puerto Rican couples, we find that partners share more similar genomic ancestries, which is characterized as the fractions of genome that come from European, Native American, and African ancestries, than random pairs of individuals from the same community. Our analysis shows that this similarity cannot be explained by the individuals’ socioeconomic factors alone.” – h/t ben southwood and jayman!

Cognitive ability and tattoos and piercings – from emil kirkegaard. (full disclosure: i don’t have any tattoos, nor do i have any “extreme” piercings. (~_^) )

G. E. Moore Contra Edvard Westermarck and The Moral Philosophy of G. E. Moore, or Why You Don’t Need to Bother with Aristotle, Hegel, and Kant – from helian.

Corruption In Eastern Europe: Tail Or Dog? – from malcolm pollack.

Huxley: Brave New World Revisited – from steve hsu. also Houellebecq on Tocqueville, Democracy, and Nietzsche.

Crashing the Gates: A Crash Course – from m.g. @thosewhocansee on the european migrant crisis.

Changes in Inequality and Generalized Trust in Europe“This paper analyses the determinants of trust in a pool of 34 European countries over the period 2002–2012. We find that income inequality is negatively related with generalized trust when we analyze the pooled data of individuals with multilevel models, confirming a well-established result in the analysis of cross-country differences in trust…. In contrast, in the fixed effects models, we find negative and significant effects of ethnic and linguistic fractionalization, discrimination (general or based on migrant status) and crime rates on trust.” – behind a paywall.

Why Did Asian America Abandon the GOP? – short answer: the shifting composition of asian americans. – from t.greer.

Het ‘verboden onderwerp’: Inteelt is weldegelijk moslimprobleem – from joost niemöller. in dutch [obv]. h/t sam schulman! who tweeted: “Warning to geneticists: stay out of the #Netherlands. They’re arresting those who mention cousin marriage.”

bonus: Did Africa’s Apes Come From Europe?“Fossil evidence hints that the common ancestor of gorillas, chimpanzees and humans evolved in Europe.” – h/t billare!

bonus bonus: The greatest vanishing act in prehistoric America“Seven centuries ago, tens of thousands of people fled their homes in the American Southwest. Archaeologists are trying to work out why.”

bonus bonus bonus: Thanet, Tanit and the Phoenicians: Place-Names, Archaeology and Pre-Roman Trading Settlements in Eastern Kent?

bonus bonus bonus bonus: Thank heavens, someone figured out which bacteria live on a donkey’s penis – (O.O)

bonus bonus bonus bonus bonus: Ancient mummified hand hidden in wall of Yorkshire cottage ‘has power to entrance humans’ – a hand of glory?!

and the tweet of the week! (i almost forgot)…

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

sorry, folks. there’s going to be another blogging lull around here for the next couple of weeks. for the same crazy, out-of-my-control reasons that i mentioned a couple of weeks ago.

i am around! just busy (d*ng it!).

in the meantime, here’s robert plomin on behavioral genetics. courtesy of DKshad0w! (^_^)


The Earliest Group Of Modern Humans To Branch Off Survived Until Just 2,300 Years Ago – h/t mr. robert ford!

Archaeologists unearth remains of oldest Norman ever found which ‘fills gap in our knowledge of pre-Neanderthal evolution’“On a bend of the river Seine near Rouen in Normandy, archaeologists have found the remains of the oldest Norman ever discovered. The three bones from the left arm of a pre-Neanderthal should shed fresh light on a little-known period. In particular, they could help scientists to understand the evolution of the squat, muscular hunters who died out 30,000 to 40,000 years ago, just after the first humans arrived in what is now Europe. The discovery of the bones at Tourville-la-Rivière, 14km south of Rouen, is exceptional because ‘this is a period with very few fossils’, according to Bruno Maureille, a palaeontologist at the National Centre for Scientific Research. He said the arm bones, dating from 200,000 years ago, in the Middle Pleistocene era, were ‘the only known example from northern Europe’.”

The first South Americans: Extreme living“After humans arrived in South America, they quickly spread into some of its most remote corners.”

How ancient DNA is rewriting human history“‘Human history is not one of stasis….’ The genetic record shows that for the past tens of thousands of years, mixed human ancestry is the rule and not the exception.” h/t hbd bibliography!

Treasure trove of ancient genomes helps recalibrate the human evolutionary clock

EmTech: Illumina Says 228,000 Human Genomes Will Be Sequenced This Year

Europe the birthplace of art? Cave art shows Indonesia has a claim“Using this method, the researchers determined that one of the hand stencils they sampled was made at least 39,900 years ago and that a painting of an animal known as a pig deer was at least 35,400 years old. In Europe, the oldest known cave painting was of a red disk found in a cave in El Castillo, Spain, that has a minimum age of 40,800 years. The earliest figurative painting, of a rhinoceros, was found in the Chauvet Cave in France; it goes back 38,827 years.”

Ancient Plague’s DNA Revived From A 1,500-Year-Old Tooth – justinian plague. – h/t debbie kennett!

New Genetic ‘Operating System’ Facilitated Evolution of ‘Bilateral’ Animals

Draft of paper about Amish“[T]he difference in mean AQ [‘amishness’] between young Amish men and their non-Amish neighbors is about 2.8 standard deviations. In the IQ world this would correspond to a group different of 42 points. In the stature world this would correspond to a height difference of about 8 inches.” – from henry harpending. see also Amish v. English from steve sailer.

Does evolutionary theory need a rethink? – no. – see also Evolution Ever Evolves from razib.

Widespread signals of convergent adaptation to high altitude in Asia and America

Evolutionary behavioral genetics“We describe the scientific enterprise at the intersection of evolutionary psychology and behavioral genetics — a field that could be termed Evolutionary Behavioral Genetics — and how modern genetic data is revolutionizing our ability to test questions in this field.”

coolest story! a MUST READ!: Finding Clues in Genes of ‘Exceptional Responders’“One study at Memorial Sloan-Kettering Cancer Center tested a drug called everolimus that is approved for kidney and breast cancer. Researchers asked if it could treat bladder cancer. Forty-five patients received the drug. Two responded. ‘The verdict was, “O.K., I guess everolimus does not work in bladder cancer,” ‘ said Dr. David Solit, the principal investigator. But then there were those two patients — one, in particular. Her cancer had spread to her abdomen. She was expected to live less than a year, and there was no treatment for her. But with everolimus, her tumors disappeared. ‘I was at a clinical meeting, and everyone was saying this drug did not work,’ Dr. Solit said. ‘I said, “It worked for her.” ‘ The investigators found out why. Her cancer had a mutation in a gene that made it dependent on a protein, mTOR, for growth. Everolimus squelches the activity of mTOR. The woman is still taking everolimus, and her cancer has not recurred.”

Are adoption gains on the g factor? A meta-analysis“g loadings and adoption gains yield a correlation of −1.” – from te nijenhuis, jongeneel-grimen, and armstrong. – h/t erwin schmidt!

The high heritability of educational achievement reflects many genetically influenced traits, not just intelligence“Genetic research has shown that intelligence makes a major contribution to the heritability of educational achievement. However, we show that other broad domains of behavior such as personality and psychopathology also account for genetic influence on GCSE scores beyond that predicted by intelligence. Together with intelligence, these domains account for 75% of the heritability of GCSE scores. These results underline the importance of genetics in educational achievement and its correlates.” – (because there’s more to hbd than just iq!)

Psychology in the 21st Century“Highly recommended: slides from a recent talk [‘The Genetic Architectures of Psychological Traits’] by James Lee.”

Replicability and Robustness of Genome-Wide-Association Studies for Behavioral Traits“Our results show that large and therefore well-powered genome-wide-association studies can identify replicable genetic associations with behavioral traits.”

Intelligence Is Critical to the Future of Humankind“A conversation with Douglas Detterman, editor of the journal Intelligence” – h/t holtz!

Crime, income, educational attainment and employment among immigrant groups in Norway and Finland – new paper from emil kirkegaard.

Is there no population genetic ‘support’ for a racial hereditarian hypothesis? – h/t jayman! who tweeted: “Racial admixture studies across the Americas all find relationship between ancestry & educational attain. as expected.”

Heavier babies do better in school“A study of children in Florida found that those who were heavier at birth scored higher on math and reading tests in the third to eighth grades.”

Practice Does Not Make Perfect“We are not all created equal where our genes and abilities are concerned.”

another MUST READ, this one from steve sailer: The Bell Curve 20 years later: A New Caste Society. – see also: ‘The Bell Curve’ Turns 20 from robert verbruggen.

Race, Income, and Test Scores – also from robert verbruggen.

The role of lactase persistence in precolonial development“It is shown through a number of specifications that country-level variation in the frequency of lactase persistence is positively and significantly related to population density in 1,500 CE; specifically, a one standard deviation increase in the frequency of lactase persistent individuals (roughly 24 percentage points) is associated with roughly a 40 % increase in precolonial population density.”

Common variants and the biological and genomic architecture of human height“The latest from the GIANT collaboration. They are also estimating ~ 10k causal variants in total, with 697 now identified at genome-wide significance…. With ~1k variants to work with, we can expect progress on the question of whether the ~1 SD group difference in height between north and south europeans is due to selection. Uniformly higher SNP frequencies in the north for variants that slightly increase height would be strong evidence of selection.” – original research paper: Defining the role of common variation in the genomic and biological architecture of adult human height

Big Chickens“More evidence that common genetic variants can produce many standard deviations of change in average phenotype.”

The Giant Mutations in the Human Genome“It turns out that there is a class of giant DNA mutations that share features of developmental disorders: They are surprisingly common, frustratingly diverse, and hard to categorize. Researchers are now discovering that these mutations play a big role in developmental delay disorders. The baffling symptoms are a consequence of the underlying genetic turmoil…. These large mutations are called ‘copy number variants’ or CNVs, and they add or subtract copies of genes.”

Genetic and nonshared environmental factors predict handgun ownership in early adulthood“Analyses revealed a stronger concordance for gun ownership among identical twins as compared to fraternal twins and univariate ACE model results indicated genetic (57%) and nonshared environmental (43%) factors explained the variance in handgun ownership.” – h/t amir sarislan!

Different tastes for different individuals – h/t jayman! who tweeted: “Genetic evidence of recent evolutionary differentiation in taste response across the world.”

From Kale To Pale Ale, A Love Of Bitter May Be In Your Genes

Here’s why you’re bouncing off the walls: the genetics of coffee consumption“Coffee consumption has now been linked to eight genetic variants.”

Do Political Attitudes and Religiosity Share a Genetic Path? – h/t avi tuschman!

Unpacking “evil”: Claiming the core of the Dark Triad

The slow and fast life histories of early birds and night owls: Their future- or present-orientation accounts for their sexually monogamous or promiscuous tendencies – uh oh. i’m a night owl!

Later school start time ‘may boost GCSE results’“Thousands of teenagers are to get an extra hour in bed in a trial to see whether later school start times can boost GCSE results. University of Oxford researchers say teenagers start functioning properly two hours later than older adults…. Prof Russell Foster, director of sleep and circadian neuroscience at Oxford University, said that getting a teenager to start their day at 07:00 is like an adult starting theirs at 05:00.”

How Iceland’s Genealogy Obsession Leads to Scientific Breakthroughs

Infidelity and kin selection: Does cheating seem as bad when it’s “all in the family”?“[C]ontrary to predictions generated by kin selection theory, participants tended to report that they would feel worse if their partners had sex with their relatives. We propose several explanations for the current findings and discuss their implications for kin selection theory.” – h/t neuroskeptic!

Anthropologists find that even among egalitarian forager-farmers, social status can impact health and happiness

Africa is on time“Using survey data on African income distributions and national accounts GDP, we estimate income distributions, poverty rates, and inequality indices for African countries for the period 1990–2011. We show that: (1) African poverty is falling rapidly…. All classes of countries, including those with disadvantageous geography and history, experience reductions in poverty. In particular, poverty fell for both landlocked as well as coastal countries; for mineral-rich as well as mineral-poor countries; for countries with favorable or with unfavorable agriculture; for countries regardless of colonial origin; and for countries with below- or above-median slave exports per capita during the African slave trade.” – h/t mugwump!

Ethnic Divisions and Production in Firms“A body of literature suggests that ethnic heterogeneity limits economic growth. This paper provides microeconometric evidence on the direct effect of ethnic divisions on productivity. In team production at a plant in Kenya, an upstream worker supplies and distributes flowers to two downstream workers who assemble them into bunches. The plant uses an essentially random rotation process to assign workers to positions, leading to three types of teams: (a) ethnically homogeneous teams, and teams in which (b) one or (c) both downstream workers belong to a tribe in rivalry with the upstream worker’s tribe. I find strong evidence that upstream workers undersupply non-coethnic downstream workers (vertical discrimination) and shift flowers from non-coethnic to coethnic downstream workers (horizontal discrimination), at the cost of lower own pay and total output.” – spite! it’s so funny. – h/t ben southwood!

Statistics in educational research – on statistical significance and p-values from andrew sabisky.

Social Network Analysis Shows Direct Evidence for Social Transmission of Tool Use in Wild Chimpanzees – h/t razib!

Reparations for Slavery? – from those who can see.

Researchers Have Identified The Origin Of The HIV/AIDS Pandemic

The Human Genome Is In Stalemate in the War Against Itself

Winter is coming: do you really need a flu jab? – from tom chivers who tweeted: “On the flu jab, and the evidence, and lack of evidence, thereof.”

(Re)Becoming Human“As the sun set over Lake Eyasi in Tanzania, nearly thirty minutes had passed since I had inserted a turkey baster into my bum and injected the feces of a Hadza man – a member of one of the last remaining hunter-gatherers tribes in the world – into the nether regions of my distal colon. I struggled to keep my legs in the air with my toes pointing towards what I thought was the faint outline of the Southern Cross rising in the evening sky. With my hands under my hips – and butt perched against a large rock for support – I peddled an imaginary upside down bicycle in the air to pass the time as I struggled to make sure my new gut ecosystem stayed put inside me. With my butt cheeks flexed and my, you know what puckered, I wondered if I had just made a terrible mistake….”

Strange Seeds on Distant Shores – a look at albion’s seed and american nations, etc., etc. – h/t jayman!

Remains of Alexander the Great’s Father Confirmed Found

Diversity: A Nature & Scientific American special issue – *facepalm*

Philosophy is a Bunch of Empty Ideas: Interview with Peter Unger – (^_^)

bonus: New particle is both matter and antimatter – phreaky physics!

bonus bonus: Physicist turns smartphones into pocket cosmic ray detectors – really cool physics!

bonus bonus bonus: A Kindle loaded with e-books is heavier than an empty one – so there!

bonus bonus bonus bonus: The Questioning of John Rykener, A Male Cross-Dressing Prostitute, 1395 (in london) – shocking!

bonus bonus bonus bonus bonus: Around the world in 400,000 years: Journey of the red fox“[T]his new research shows that the red foxes of North America and Eurasia have been almost entirely reproductively isolated from one another for roughly 400,000 years. During this time, the North American red fox evolved into a new species distinct from its Old World ancestors…. The new genetic research further suggests that the first red foxes originated in the Middle East before beginning their journey of colonization across Eurasia to Siberia, across the Bering Strait and into North America, where they eventually founded the North American population.”

bonus bonus bonus bonus bonus bonus: Cosmic Karma: Mosquitoes Have Flying, Blood-Sucking Parasite of Their Own

bonus bonus bonus bonus bonus bonus bonus: Kangaroos have three vaginas!

(note: comments do not require an email. and just to make your head asplode…. (^_^) )














so this paper was making the rounds on twitter earlier in the week…

Demonstrating the Validity of Twin Research in Criminology [pdf]

…and everyone was like, “you have GOT to read this!” so i did. and, yeah, it’s really good! i highly recommend having a read of it.

the paper was written as a response to another paper entitled Pulling back the curtain on heritability studies: Biosocial criminology in the postgenomic era.

postgenomic? wt…? what planet do those guys live on?

anyway…Demonstrating the Validity makes many very right and very interesting points including the following:

1) a common assumption in behavioral genetics analyses is that human matings are random (they’re not — there’s a whole lot of assortative mating when humans go forth and multiply) and that assumption can lead to an underestimate of heritability estimates.

2) another assumption — the equal environments assumption (i.e. that both identical and fraternal twins share equal environments as kids) — leads to an overestimate of heritability estimates.

the authors of the paper show, however, that since these two assumptions are often found together in twin studies, that the over- and underestimates wind up more or less balancing each other out (see below — and see the paper!).

(i, of course, couldn’t help thinking that if assortative mating leads to underestimates of heritability, what would lots of inbreeding in a population do? so far, all twins studies have come from w.e.i.r.d. populations, though — afaik — so the inbreeding issue prolly doesn’t matter. but, if you should ever see some heritability estimates coming out of saudi arabia or sicily, heads up!)

other important points from the paper [my emphases in bold]:

When multiple divergent methods converge to illustrate a consistent finding, it is logically reasonable and empirically sound to accept as valid the results of the divergent methods. The primary reason for such a conclusion is the nonoverlapping assumptions underlying the various methods. This dynamic is illustrated in the convergence in findings between classical twin design studies and various molecular genetics methodologies. GCTA and CSG studies are examples of methodologies that are not subject to the same assumptions as classical twin designs and yet provide convergence in terms of the differential influence of genetic and environmental factors on a variety of behavioral phenotypes, including antisocial behavior. In direct contrast to the appraisal provided by Burt and Simons, the most cutting-edge research emanating from molecular genetics relies heavily on the findings of classical twin design studies and is continually providing empirical support for the validity of such studies.”

oh yeah!


“We have shown empirically that violations of the assumptions of behavioral genetics studies do not invalidate heritability estimates. This is not a matter of opinion but a matter of mathematical evidence. Under certain conditions, our calculations and simulations revealed that heritability estimates will be slightly upwardly biased (probably no more than 5–10 percentage points). Under other conditions, heritability estimates will be downwardly biased (probably no more than 5–10 percentage points). Under the most likely condition, where multiple violations occur simultaneously, the biasing influences of assumption violations wash out, with upwardly biasing factors canceling downwardly biasing factors. Moreover, the overall pattern of findings flowing from the 61 studies examining the EEA revealed the same conclusions offered by our calculations and simulation data. Needless to say, no ‘fatal flaw’ in behavioral genetic methodologies or assumptions has been discovered and the conclusion that ‘all of these models are biased toward inflating heritability and underestimating shared environmental influences’ (Burt and Simons, 2014: 226, emphasis in original) is unequivocally incorrect.”

good stuff! read the whole thing here! and don’t miss all the supplementary materials here!

(note: comments do not require an email. identical. almost.)

too bad he didn’t get his behavioral genetics right, though. but that’s ok. he was ahead of the times. from The Muqaddimah: An Introduction to History; In Three Volumes – I [pgs. 105-106]:

“14. Prestige lasts at best four generations in one lineage

“The world of the elements and all it contains comes into being and decays. Minerals, plants, all the animals including man, and the other created things come into being and decay, as one can see with one’s own eyes. The same applies to the conditions that affect created things, and especially the conditions that affect man. Sciences grow up and then are wiped out. The same applies to crafts, and to similar things.

“Prestige is an accident that affects human beings. It comes into being and decays inevitably. No human being exists who possesses an unbroken pedigree of nobility from Adam down to himself. The only exception was made in the case of the Prophet, as a special act of divine grace to him, and as a measure designed to safeguard his true character.

“Nobility originates in the state of being outside. That is, being outside of leadership and nobility and being in a base, humble station, devoid of prestige. This means that all nobility and prestige is preceded by the non-existence of nobility and prestige, as is the case with every created thing.

It reaches its end in a single family within four successive generations. This is as follows: The builder of the family’s glory know what it cost him to do the work, and he keeps the qualities that created his glory and made it last. The son who comes after him had personal contact with his father and thus learned those things from him. However, he is inferior to him in this respect, inasmuch as a person who learns things through study is inferior to a person who knows them from practical application. The third generation must be content with imitation and, in particular, with reliance upon tradition. This member is inferior to him of the second generation, inasmuch as a person who relies upon tradition is inferior to a person who exercises independent judgement.

The fourth generation, then, is inferior to the preceding ones in every respect. Its member has lost the qualities that preserved the edifice of its glory. He despises (those qualities). He imagines that the edifice was not built through application and effort. He thinks that it was something due his people from the very beginning by virtue of the mere fact of their descent, and not something that resulted from group (effort) and (individual) qualities. For he sees the great respect in which he is held by the people, but he does not know how that respect originated and what the reason for it was. He imagnes that it is due to his descent and nothing else. He keeps away from those in whose group feelings he shares, thinking that he is better than they. He trusts that (they will obey him because) he was brought up to take their obedience for granted, and he does not knw the qualities that made obedience necessary. Such qualities are humility (in dealing) with (such men) and respect for their feelings. Therefore, he considers them despicable, and they, in turn, revolt against him and despise him. They transfer leadership from him and his direct lineage to some other related branch, in obedience to their group feeling, after they have convinced themselves that the qualities of the (new leader) are satisfactory to them. His family then grows, whereas the family of the original (leader) decays and the edifice of his ‘house’ collapses.

“That is the case with rulers who have royal authority. It also is the case with all the ‘houses’ of tribes, of amirs, and of everybody else who shares in a group feeling, and then also with the ‘houses’ among the urban population. When one ‘house’ goes down, another one rises in another group of the same descent.

The rule of four (generations) with respect to prestige usually holds true. It may happen that a ‘house’ is wiped out, disappears, and collapses in fewer than four, or it may continue unto the fifth and sixth generations, though in a state of decline and decay. The four generations can be defined as the builder, the one who has personal contact with the builder, the one who relies on tradition, and the destroyer.”

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

Crickets in two places fall silent to survive“To hide themselves from deadly flies, crickets on two Hawaiian islands have evolved an inability to sing. Ten years ago, two years apart, males appeared on Kauai and Oahu with altered wings, which they would normally rub together to chirp and attract females. New findings published in the journal Current Biology show that the wing changes are physically different and arose from separate mutations. This makes the silent crickets a brand new example of ‘convergent evolution’.” – and some really rapid evolution!

Microbes May Drive Evolution of New Animal Species“[S]ymbiosis — a long-term, stable and often beneficial interaction between organisms — could drive two populations apart, the first step in the development of new species. Although the idea has been floating around for nearly a century, it has only recently begun to gain traction in biology. This idea contrasts sharply with the traditional picture of evolution, in which new species emerge either from geological isolation or from a relentless struggle for food and mates. According to this new hypothesis, a host organism’s microbes might trigger changes in mating and reproduction that begin to define two different populations.” – h/t charles!

you gotta read this!: Coincidental Killers“We assume that microbes evolved to attack humans when actually we are just civilian casualties in a much older war…. Many of the pathogens we fear most are mere tourists on the human body. Their real homes are oceans, caves, or soils. To understand them, we need to understand them within their natural ecology. Soil, for example, is an extreme habitat for a microbe: harsh and constantly changing. It can quickly oscillate from flood to drought, from scalding heat to freezing cold, and total darkness to intense solar radiation. It’s rife with other competing microbes, and crawling with hungry predators. We fear lions and tigers and bears; bacteria have to contend with phage viruses, nematode worms, and predatory amoebas. All of these conditions can lead to adaptations that make microbes accidentally suited for life in a human host. We are, after all, just another environment. A thick capsule that shields a microbe from dehydration could also shield it from our immune system. A spore that is adapted for travelling through the air can be easily inhaled into a respiratory tract.”

Genetically identical ants help unlock the secrets of larval fate“A young animal’s genes are not the only genes that determine its fate. The genetic identity of its caretakers matters too…. [A] team led by Serafino Teseo of the University of Paris 13 used the unique aspects of the [clonal] ants’ biology to test the indirect role genes play in shaping the future identity of larvae and whole colonies by looking at the interaction between larvae and adults. They did so by observing the success of two ant clones, A and B, in pure colonies or mixed together into chimeric colonies. They also swapped broods, so A adults raised B larvae and vice versa. It turned out that A and B larvae developed differently depending on whether A or B nurses raised them. Left alone, pure A colonies produced the most young after six generations, making them more successful than B. However, in mixed colonies, B did better because its larvae more frequently turned into large adults that specialize in egg-laying rather than smaller, foraging-focused individuals….” – h/t rolf muertter!

Mitochondrial DNA of first Near Eastern farmers is sequenced for the first time“According to conclusions, genetic affinities have been observed between the mitochondrial DNA of first Neolithic populations and the DNA of first Catalan and German farmers. This suggests that probably Neolithic expansion took place through pioneer migrations of small groups of population. Moreover, the two main migration routes — Mediterranean and European — might have been genetically linked. ‘The most significant conclusion — highlights Eva Fernández — is that the degree of genetic similarity between the populations of the Fertile Crescent and the ones of Cyprus an Crete supports the hypothesis that Neolithic spread in Europe took place through pioneer seafaring colonization, not through a land-mediated expansion through Anatolia, as it was thought until now….’ Other scientific studies had already provided signs of an alternative scenario of Neolithic spread in Europe different from the one through Anatolia. According to Turbón, ‘recent archaeological finds have proved that the Neolithic arrived to Cyprus around 10,600 years ago, some years after the first documentation of agricultural practices in the Near East.’ Architecture and burial models found in Cyprus’ sites are similar to the ones found in the Middle Euphrates basin, ‘that indicates a direct colonisation of these territories,’ highlights the author. ‘Besides, spatial interpolation of radiocarbon dates from different Neolithic sites in the Near East and Europe also suggests a first seafaring expansion through Cyprus,’ he concludes.” – orginal research article.

The Giant Rat of Sumatra and Sardinia and No True Sardinian – from greg cochran.

A twist in Austronesian origins“The Taiwanese origin of Austronesians is widely accepted. A new preprint confirms this theory, but adds a new twist to the story of Austronesian dispersals, as it seems that in their western expansion, Austronesians picked up some Austroasiatic ancestry. This means either that Austroasiatic speakers preceded them in islands where Austronesian languages are now spoken, or that the Austronesians picked up this kind of ancestry in the mainland before settling in the islands.” – from dienekes.

A new allele for blond hair“There is a widespread belief that whatever made Europeans fair-skinned also gave them their unique palette of hair and eye colors. In reality, fair skin has only a weak genetic linkage with either non-black hair or non-brown eyes.” – from peter frost. see also: A molecular basis for classic blond hair color in Europeans.

A Genetic Map of Fireworks in Time“French Canadians and Slavs are both cases of populations which were once relatively modest and began in a narrow delimited region, but now are quite expansive and numerous. In the case of the East Slavs the demographic expansion also entailed the absorption of numerous Uralic tribes, as well as later Turks. And this illustrates one of the major details which I think has characterized the genetic turnover of human populations: phase shifts from a relatively static one defined by isolation by distance gene flow across clinal gradiants, to a rapid expansion of a small subset, and the overlay of this component as a palimpsest over the underlying variation. In some cases the replacement is nearly total, as in the modern United States. In other cases, as among Great Russians, the Slavic affinities of this population, and its association with Poles and other groups are clear, but there was a non-trivial uptake of exogenous segments which might allow for a reconstruction of the prior genetic landscape. These changes occur over short periods, and are bright fireworks against the comparatively static firmament.” – from razib.

Male faces ‘buttressed against punches’ by evolution“A new theory suggests that our male ancestors evolved beefy facial features as a defence against fist fights. The bones most commonly broken in human punch-ups also gained the most strength in early “hominin” evolution. They are also the bones that show most divergence between males and females.” – h/t darwin evolution! – original research article.

Faster eye responses in Chinese people not down to culture“New research from University of Liverpool scientists has cast doubt on the theory that neurological behaviour is a product of culture in people of Chinese origin. Scientists tested three groups – students from mainland China, British people with Chinese parents and white British people – to see how quickly their eyes reacted to dots appearing in the periphery of their vision…. The findings, published in the journal PLoS One, revealed that similar numbers of the British Chinese and mainland Chinese participants made high numbers express saccades, with the white British participants made far fewer. Culturally the British Chinese participants were similar to their white British counterparts and different to the mainland Chinese students.”

Cultural differences in human brain activity: A quantitative meta-analysis“East Asians show enhanced activity underlying mentalizing and emotion regulation. Westerners show enhanced activity underlying self-reflection and emotional responses.”

Race could be a factor in head, neck cancer survival rates“The national survival rates for African-Americans diagnosed with head and neck cancer have not improved in the last 40 years despite advances in the treatment and management of the disease, researchers have found. The researchers suggest that inherent genetic factors in African-Americans may make some tumors resistant to treatments.”

Severe intellectual disability diagnosed by analysis of entire genome“[A]lmost all mental impairments are caused by new mutations that have not yet occurred in father or mother.” – h/t mr. robert ford!

New genes involved in food preferences will revolutionize diets and improve health“The researchers undertook genome wide association studies (GWAS) to try to unravel the genetic basis for certain food preferences. 2311 Italian subjects participated in the discovery step, while 1755 from other European countries and from Central Asia were used in order to further verify the findings. They uncovered 17 independent genes related to liking for certain foods, including artichokes, bacon, coffee, chicory, dark chocolate, blue cheese, ice cream, liver, oil or butter on bread, orange juice, plain yoghurt, white wine and mushrooms. Surprisingly, none of the genes thus identified belonged to the category of taste or smell receptors…. In a second study, the researchers amassed the response of around 900 healthy adults from North Eastern Italy to salt, and related this to a DNA sequence variation found on the KCNA5 gene, known to be related to taste pathways in mammals.”

First direct evidence for human sex pheromones“‘By using dynamic point-light displays that portray the gaits of walkers whose gender is digitally morphed from male to female, we show that smelling androstadienone systematically biases heterosexual females, but not males, toward perceiving the walkers as more masculine. By contrast, smelling estratetraenol systematically biases heterosexual males, but not females, toward perceiving the walkers as more feminine. Homosexual males exhibit a response pattern akin to that of heterosexual females, whereas bisexual or homosexual females fall in between heterosexual males and females. These effects are obtained despite that the olfactory stimuli are not explicitly discriminable. The results provide the first direct evidence that the two human steroids communicate opposite gender information that is differentially effective to the two sex groups based on their sexual orientation.'” – @deric bownds’ mindblog.

Genetic relatedness predicts contact frequencies with siblings, nieces and nephews: Results from the Generational Transmissions in Finland surveys“Individuals have more contacts with full than with half siblings. Individuals have more contacts with nieces/nephews via full than via half siblings. Individuals have more contacts with nieces/nephews via sisters than via brothers.” – h/t jayman!

Beware Armchair Psychoanalysis“‘Behavioral genetic studies have proved beyond a shadow of a doubt that heredity is responsible for a sizable portion of the variations in people’s personalities. Some people are more hot-tempered or outgoing or meticulous than others, and these variations are a function of the genes they were born with as well as the experiences they had after they were born. The exact proportion— how much is due to the genes, how much to the experiences—is not important; the point is that heredity cannot be ignored.'” – from jayman (quoting judith rich harris there).

SD-IE and other differentiation effects in Italy and Spain [pdf] – “SD–IE [strategic differentiation–integration effort] is a strategic differentiation effect present amongst indices of life history (LH), such that persons and populations of slow LH are more differentiated compared to those of fast LH. We found that this phenomenon is present amongst provinces in Italy and Spain, similarly to demonstrations among US states and Japanese prefectures. The average effect size of SD–IE was found to be bigger in Spain and Italy….. In the present study, we test SD–IE using regional-level data for counties in Spain and Italy.”

Is the smart fraction as valuable as previously thought?“‘Consistent with the intellectual class theory advocated by Rindermann and Thompson (2011) and Rindermann et al. (2009), our research findings showed strong evidence that those people that have high IQ are the most relevant influence on economic development. Although our results suggested that all three examined IQ categories promote higher economic growth, the intellectual class has the highest impact followed by the mean ability and non-intellectual classifications. Similarly, the intellectual class also has a highly significant effect on generating technological progress, whereas the influence of the other two groups is immaterial.'” – @dr. james thompson’s blog.

HVGIQ: Burma and HVGIQ: U.S. Virgin Islands – from jason malloy.

Life unworthy of life – post about, as jayman put it, who supports eugenics. – from the awesome epigone.

The Biology of Risk“The state of your body predicts your appetite for financial risk just as it predicts an athlete’s performance. If we understand how a person’s body influences risk taking, we can learn how to better manage risk takers. We can also recognize that mistakes governments have made have contributed to excessive risk taking.”

We can’t ignore the evidence: genes affect social mobility“Why do so many people fail to accept the overwhelming evidence that genes contribute to academic achievement and thereby social status?” – h/t hbd bibliography!

India’s Feudal Rapists

Old chaps? 3,300-year-old trousers found in China may be world’s oldest“Animal-fur menswear found on the bodies of two mummies in Xinjiang province ‘almost the same shape as today’s trousers'”

Grave find may be Western Europe’s earliest false tooth“Archaeologists have identified what could be remains of the earliest false tooth found in Western Europe. The dental implant comes from the richly-furnished timber burial chamber of an Iron Age woman that was excavated in Le Chene, northern France.”

Cat People Are Smarter Than Dog People, New Study Shows – (~_^) – ftr, i like both. i’m not a speciesist!

bonus: Blind cavefish are able to ‘count’“Blind cave-dwelling fish are able to discriminate between different quantities, scientists say…. Researchers say it is the first time non-visual numerical abilities have been shown in fish.” – h/t mo costandi!

bonus bonus: Bees build mental maps to get home“Study suggests the insects do not rely solely on the Sun as a compass…. ‘The surprise comes for many people that such a tiny little brain is able to form such a rich memory described as a cognitive map,’ says co-author Randolf Menzel, a neurobiologist at the Free University of Berlin.”

bonus bonus bonus: Nemo’s Dad Should Have Become His Mom, And Other Lies Children’s Movies Told You – h/t steve stewart williams!

(note: comments do not require an email. “i wandered lonely as a cloud….”)

from jayman!:


previously: it’s not nature and nurture…

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


Get every new post delivered to your Inbox.

Join 395 other followers