Archive for December, 2011

Richard Feynman's intelligence

By Razib Khan | December 27, 2011 1:32 am

Interesting interview of Steve Hsu. I’ll reproduce the part about Feynman:

3. Is it true Feynman’s IQ score was only 125?

Feynman was universally regarded as one of the fastest thinking and most creative theorists in his generation. Yet it has been reported-including by Feynman himself-that he only obtained a score of 125 on a school IQ test. I suspect that this test emphasized verbal, as opposed to mathematical, ability. Feynman received the highest score in the country by a large margin on the notoriously difficult Putnam mathematics competition exam, although he joined the MIT team on short notice and did not prepare for the test. He also reportedly had the highest scores on record on the math/physics graduate admission exams at Princeton. It seems quite possible to me that Feynman’s cognitive abilities might have been a bit lopsided-his vocabulary and verbal ability were well above average, but perhaps not as great as his mathematical abilities. I recall looking at excerpts from a notebook Feynman kept while an undergraduate. While the notes covered very advanced topics for an undergraduate-including general relativity and the Dirac equation-it also contained a number of misspellings and grammatical errors. I doubt Feynman cared very much about such things.

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CATEGORIZED UNDER: Psychology
MORE ABOUT: Richard Feynman

The aliens among us

By Razib Khan | December 26, 2011 3:48 pm

Amy Harmon has a very long piece in The New York Times, Navigating Love and Autism. It’s about a couple who both have been diagnosed with Asperger syndrome. Like cancer I suspect that this term brackets a lot of different issues into one catchall label, not to mention the acknowledgment that it’s a spectrum. When I spent time with the Bay Area Less Wrong community I would observe the range in tendencies and neurological diversity of people who clearly would be classified as “high functioning autistic” (to be clear, these were individuals strongly selected for high general intelligence, with a minimum threshold of around two standard deviations above the norm). The lack of comprehension of religiosity and bias toward libertarianism were two salient characteristics of this sect (though people who have met me don’t classify me as having Asperger syndrome, I have these two cognitive biases myself)

 

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CATEGORIZED UNDER: Psychology
MORE ABOUT: Asperger syndrome

The sons of Adam: spirit, not blood

By Razib Khan | December 26, 2011 3:08 pm


Hominin increase in cranial capacity, courtesy of Luke Jostins


A few years ago a statistical geneticist at Cambridge’s Sanger Institute, Luke Jostins, posted the chart above using data from fossils on cranial capacity of hominins (the human lineage). As you can see there was a gradual increase in cranial capacity until ~250,000 years before the present, and then a more rapid increase. I should also note that from what I know about the empirical data, mean human cranial capacity peaked around the Last Glacial Maximum. Our brains have been shrinking, even relative to our body sizes (we’re not as large as we were during the Ice Age). But that’s neither here nor there. In the comments Jostins observes:

The data above includes all known Homo skulls, but none of the results change if you exclude the 24 Neandertals. In fact, you see the same results if you exclude Sapiens but keep Neandertals; the trends are pan-Homo, and aren’t confined to a specific lineage….

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D.I.Y. population structure analysis

By Razib Khan | December 26, 2011 1:09 pm

I badger readers here to actually use all the analytic tools which researchers put out into public circulation, rather than just offering cheap opinions. Obviously it’s way more fun and informative to have discussions with someone who can check their own hunches by doing a few “runs” overnight. Secondly, if you have minimal technical skills all it requires is an investment of time. If you can’t be bothered to invest the time if you have a modicum of nerd-quotient then it says something about how passionate you are about these issues in my opinion (granted, life gets in the way, but as someone who routinely felt lucky to sleep 3 hours on many nights over the past 3 months, please spare me).

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CATEGORIZED UNDER: Anthroplogy
MORE ABOUT: Admixture

Have a merry Christmas!

By Razib Khan | December 25, 2011 2:03 am

And, if applicable, Hanukkah, and/or Kawanzaa, Yule!

CATEGORIZED UNDER: Blog
MORE ABOUT: Christmas

D. S. Falconer, 1913-2004

By Razib Khan | December 24, 2011 2:04 pm

In response to comments and queries below I’ve been poking around for more experimental material on quantitative genetics, and in particular the breeder’s equation. That’s how I stumbled upon this very interesting and informative obituary of D. S. Falconer in Genetics. It reviews not only the biographical details of Falconer’s life, but much of his science. It’s free to all now, so I highly recommend it! (as well as Introduction to Quantitative Genetics, which is quite pricey right now, but just keep watching, I recall getting a relatively cheap copy of the 1996 edition) Curiously, quantitative genetics is rather unknown to the general public in comparison to the biophysical sexiness of molecular genetics, but in most ways it’s the much better complement to the “folk genetics” which often crops up in our day to day life (e.g., “why is so-and-so’s son so short when so-and-so is so tall”). DNA illuminates the discontinuities of Mendelian inheritance, often in the gloomy realm of disease, but quantitative genetics sheds light on the continuities and variations we see across the generations.

CATEGORIZED UNDER: Quantitative Genetics

How much do siblings differ in height?

By Razib Khan | December 24, 2011 1:28 pm

In the comments below a reader asks about the empirical difference in heights between siblings. I went looking…and I have to say that the data isn’t that easy to find, people are more interested in the deeper inferences on can make from the resemblances than the descriptive first-order data itself. But here’s one source I found:


Average difference Identical twins Identical twins raised apart Full siblings
Height, inches 0.67 0.71 1.8
Weight, pounds 4.2 9.9 10.4
IQ 5.9 8.2 9.8

These data indicate that IQ and height variation among sibling cohorts is on the order of ~2/3rd to 3/4th of the variation that one can find within the general population (my estimate of standard deviation of 2.5 inches for height below is about right, if a slight underestimate according to the latest data). But I also found a paper with more detailed statistics.

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CATEGORIZED UNDER: Quantitative Genetics

The reasons for the seasons

By Razib Khan | December 24, 2011 12:27 pm

John Farrell points me to this interesting post, Whose Christmas Is It Anyway?, which reports on revisionist scholarship which expresses skepticism that the Roman Christian celebration of Christmas on December 25th is a co-option of Dies Natalis Solis Invicti, the celebration of the birth of Sol. The context is that in the 3rd century various forms of astral religion, often of eastern provenance, became rather prominent across the Roman Empire. These cults received ad hoc imperial patronage due to the devotion of particular emperors, such as Aurelian. Though the cult of Sol never attained a religious monopoly analogous to Christianity, the rise of the latter in the 4th century is best understood with the prominence of the former in the 3rd century kept in mind. So, for example, the peculiarity of early depictions of Jesus Christ to the modern eye may simply be a function of the cultural milieu in terms of the expectations of what a god would look like. The transfer of rituals from the solar religion of the 3rd and 4th century down to Christian late antiquity is noted for the Roman aristocracy, mostly because the clerical elite of the period inveighed against these persistence pagan forms of reverence of the divine.

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CATEGORIZED UNDER: Culture
MORE ABOUT: Christmas

A mediocre man's great son, a great man's mediocre son

By Razib Khan | December 24, 2011 1:26 am

Kobe Bryant is an exceptional professional basketball player. His father was a “journeyman”. Similarly, Barry Bonds and Ken Griffey Jr. both surpassed their fathers as baseball players. Both of Archie Manning’s sons are superior quarterbacks in relation to their father. This is not entirely surprising. Though there is a correlation between parent and offspring in their traits, that correlation is imperfect.

Note though that I put journeyman in quotes above because any success at the professional level in major league athletics indicates an extremely high level of talent and focus. Kobe Bryant’s father was among the top 500 best basketball players of his age. His son is among the top 10. This is a large realized difference in professional athletics, but across the whole distribution of people playing basketball at any given time it is not so great of a difference.

What is more curious is how this related to the reality of regression toward the mean. This is a very general statistical concept, but for our purposes we’re curious about its application in quantitative genetics. People often misunderstand the idea from what I can tell, and treat it as if there is an orthogenetic-like tendency of generations to regress back toward some idealized value.

Going back to the basketball example: Michael Jordan, the greatest basketball player in the history of the professional game, has two sons who are modest talents at best. The probability that either will make it to a professional league seems low, a reality acknowledged by one of them. In fact, from what I recall both received special attention and consideration because they were Michael Jordan’s sons. It is still noteworthy of course that both had the talent to make it onto a roster of a Division I NCAA team. This is not typical for any young man walking off the street. But the range in realized talent here is notable. Similarly, Joe Montana’s son has been bouncing around college football teams to find a roster spot. Again, it suggests a very high level of talent to be able to plausibly join a roster of a Division I football team. But for every Kobe Bryant there are many, many, Nate Montanas. There have been enough generations of professional athletes in the United States to illustrate regression toward the mean.

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CATEGORIZED UNDER: Quantitative Genetics

The evolutionary necessity of lying

By Razib Khan | December 23, 2011 9:11 am

John Horgan has a long review of Robert Trivers’ long overdue book, The Folly of Fools: The Logic of Deceit and Self-Deception in Human Life. I really don’t care how well Trivers analyzed the topic, this is such a rich and important issue that I can’t help but think he must have hit some important mines of insight. I haven’t read The Folly of Fools, but I can recommend Natural Selection and Social Theory: Selected Papers of Robert Trivers. It’s not just a compilation of papers, there are biographical chapters which flesh out the context behind a particular idea at a given time. Trivers also shows up prominently in Defenders of the Truth: The Sociobiology Debate and Mother Nature: Maternal Instincts and How They Shape the Human Species.

CATEGORIZED UNDER: Evolutionary Psychology

The seasons

By Razib Khan | December 22, 2011 11:00 am

Over at Less Wrong there is a discussion on the Winter Solstice celebration. It being Less Wrong there’s a great deal of introspective analysis. That’s fine. When I was younger I did the “Solstice” celebration thing, though today at this age I think that if you live in the United States you should just own or disown Christmas. If you look into the history of this specific celebration it becomes clear that it isn’t so clearly specifically Christian in origin. The reality is that really just reflects the cosmopolitan materialism of the West of our day. Most people have reservations about the materialism, but there’s obviously some social and personal utility in the holiday.

In relation to another winter celebration, David Frum expresses the Jewish ambivalence toward Hanukkah, a minor holiday which had the fortune to be near Christmas on the calender. But Hanukkah is another example of “owning” something, and recreating it your own image. Frankly, I feel that in some ways Hanukkah was originally a celebration of the Al Qaeda of its day, the Maccabees. If you listen to this episode of In Our Time you can easily read between the lines and see where I’m coming from. The irony, or perhaps an expression of an iron law of history, is that the later Hasmoneans (the dynasty founded by the revolt) were themselves the sort of cosmopolitan Hellenists their ancestors disemboweled for their heresies. The Herodian scions of Hasmonean maternal heritage were  prominent figures in the court of the Julio-Claudians, before the Jewish Wars and the absorption of Hellenistic Judaism into paganism and Christianity threw up a barrier between Jewishness and the gentile world in 2nd century.

In any case, best wishes and happy holidays.

Image credit: Wikipedia

CATEGORIZED UNDER: Culture
MORE ABOUT: Christmas, Holidays

Have the "culture wars" gotten worse?

By Razib Khan | December 21, 2011 11:52 pm

The assertion in the title seems almost trivial in an impressionistic sense. There really wasn’t a strong distinction on cultural issues between Gerald Ford and Jimmy Carter in 1976. By the 1980s there definitely was a gap between George H. W. Bush and Michael Dukakis. And that chasm got wider as the years went on. I thought of this when reading this entry in Wikipedia on Jonathan Krohn, a teenager who wrote a book titled Define Conservatism. The entry in Wikipedia states:

The book outlines four fundamental principles of conservative thought: support for the United States Constitution, opposition to abortion, less government, and more personal responsibility. Krohn went on to apply the principles to current events and define whether specifically cited actions violated those principles…The book was dedicated to Ronald Reagan, William F. Buckley, Jr. and Barry Goldwater, whom Krohn describes as his political heroes, along with South Carolina Senator Jim DeMint.

What raised my eyebrows here is that Barry Goldwater did not oppose abortion rights. In fact, his wife, daughter and granddaughter have been involved in Planned Parenthood. If opposition to abortion is a key definition for what conservatism is, the reality is that conservatism didn’t exist before the 1970s, when that issue became polarized along ideological lines.

But that’s impression. What do the data say? For that, I looked at the General Social Survey.

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CATEGORIZED UNDER: Politics
MORE ABOUT: Culture Wars

The arc of primate social evolution

By Razib Khan | December 21, 2011 2:02 pm

A new paper in Nature, Stepwise evolution of stable sociality in primates, was written up in The New York Times with the provocative title, Genes Play Major Role in Primate Social Behavior, Study Finds. As noted in Joan Silk’s article on the paper it should really be phylogenetics play major role in primate social behavior. The model outlined in the paper indicates that phylogenetic relationships between major primate clades is a much better predictor of social organization and structure than simple adaptation to a specific environment, or a linear increase in social organization (group size) over time. Both of these latter dynamics would also be driven by genetic changes, and therefore tie “genes” to social behavior. In other words, genes always matter, it’s just how they matter that differs. Here’s the section of the abstract of the paper of major interest:

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The F.D.A. has better things to do than persecute Trent Arsenault

By Razib Khan | December 21, 2011 12:55 pm

For several days I’ve gotten referrals from message board discussions about the case of Trent Arsenault. Trent is a “free sperm donor” (see the link for the details). For various financial reasons he can’t adhere to all the regulations which sperm banks are subject to. I don’t dismiss the concerns out of hand, but I object to the idea that this sort of project is a rational and useful allocation of regulatory time and money. I find one section of a Reuter’s piece illuminating:

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CATEGORIZED UNDER: Bioethics
MORE ABOUT: Sperm donor

The Hobbit (2012 film)

By Razib Khan | December 21, 2011 12:19 pm

My working assumption is that this will be a regression back to the mean in relation to Peter Jackson’s The Lord of the Rings trilogy. I notice is that the projected budget for the two films is already more than a time and a half greater than all three of those earlier releases. Even accounting for inflation I suspect this is just a function of the resources now available to Jackson.

Though I assume it will at least supersede the 1977 Rankin-Bass production of the Hobbit (often parodied on South Park):

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CATEGORIZED UNDER: Culture
MORE ABOUT: Hobbit

The "best of" posts….

By Razib Khan | December 21, 2011 12:06 pm

Sam Snyder has gone through my archives back to 2006, and complied a “best of” list. Snyder admits that his interest is in “primarily centered on human behavior and health, which is the subject of most of these links.” Also, I want to caution you that 5 years is a long time, so please don’t assume that if I believe X in 2006, I continue to do so in 2011.

CATEGORIZED UNDER: Blog
MORE ABOUT: GNXP

Out of Africa to Out of Arabia

By Razib Khan | December 20, 2011 3:13 pm

Dienekes and Greg Cochran have been talking about this possibility for a few years. But a combination of archaeological finds and the current unsettled nature of the human evolutionary genomics literature means that “Out of Arabia” is a real possibility (not laugh-out-loud crazy and weird). So I took the liberty of cooking up a new design for the RichardDawkins.net website. Science is about updating our prior assumptions, so it shouldn’t be too much of an issue. What I wonder: how would the population of the Kingdom of Saudi Arabia feel about replacing Ethiopia and Kenya in human evolution documentaries? Addendum: To be clear, this isn’t to say I accept “Out of Arabia” for the origin of most modern humans, including within Africa. Rather, I think it’s not a crazy idea anymore, especially in light of the weird results which imply that West Africans may be genetically closer to non-Africans than to Pygmies and San (and it would make more sense of older uniparental results which imply back-migration from Eurasia into Africa).

CATEGORIZED UNDER: Evolution, Human Evolution

Culture evolves our bodies!

By Razib Khan | December 20, 2011 2:46 pm


Human cultural diversity


One of the most annoying aspects of talking about human evolution is the rather misguided idea that cultural evolutionary processes operate in a zero-sum environment in relation to biological evolutionary processes. The colloquial rendering of this idea is that because humans are a highly cultural plastic species, we are “beyond” biological evolution. Many researchers though suspect that on the contrary, because of cultural variation and plasticity we may be buffeted by even greater evolutionary pressures than is the norm for a relatively slow-breeding species with a small effective population size. Probably the best example of this is the ability of adults in several human populations to digest lactose sugar. This is, to not put too fine a point on it, a freak ability. Why would a mammal need to digest milk sugar as an adult after all? Well, you know why, the human mammal is wont to consume the milk of other mammals, which it has taken into bondage. Viewed from the outside the whole process is rather weird and Frankenstein-like, but we’ve been habituated to the normalcy of this sort of thing because of the diversity of cultural forms on evidence in H. sapiens (though in some societies the initial exposure to the fact that Europeans, for example, consume milk and milk products into adulthood was perceived to be highly strange).

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CATEGORIZED UNDER: Anthroplogy, Human Evolution

Human origins in 2011

By Razib Khan | December 20, 2011 12:14 pm

Interesting piece in LiveScience, What We Learned About Our Human Ancestors in 2011. The author highlights the likelihood of a lot of admixture across very diverged lineages, as well as the nascent “Out of Arabia” hypothesis. This quote from Michael Hammer gets at where we’re “going next”:

“We’ve probably just scratched the surface of what we might find,” Hammer added. “We only looked at a small number of regions of the genome. This coming year, you’ll see a lot of progress made with full genome data. This year, we should be able to confirm what we found and go way beyond that.”

I think the the lowest hanging fruit in terms of “paradigm shift” was the renewed opening to admixture with “archaic” lineages in 2010 and 2011. Before that point it was reasonable for anyone to respond to these hypotheses with a recitation of the “Out of Africa” orthodoxy. Now no longer. If admixture did no occur, then we’re talking about strange results which still need explaining with a novel model (e.g., lots of “structure” in the “Out of Africa” population due to admixture within Africa). But as the low hanging fruit is picked, researchers are now going to spread themselves out throughout the grove, hunting for numerous odds and ends. In all likelihood the picture is going to get complex, but hopefully it will be more accurate.

CATEGORIZED UNDER: Human Evolution
MORE ABOUT: Human origins

The last word on dog genesis is not nigh!

By Razib Khan | December 19, 2011 11:00 am

In my post below Rob commented:

Surely the genetic evidence is pointing towards a single domestication event (see http://news.sciencemag.org/sciencenow/2011/11/new-data-fuels-dogfight-over-the.html?ref=hp)

My general response is not to accept the latest press release about the genetic origin of dogs. I keep track of the literature and it’s rather fluid. For example, I woke up this morning, and this is what showed up in my RSS, Modern dogs are more Asian fusions than Euro pups, study finds:

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MORE ABOUT: Dogs, Domestication
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This blog is about evolution, genetics, genomics and their interstices. Please beware that comments are aggressively moderated. Uncivil or churlish comments will likely get you banned immediately, so make any contribution count!
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