A few people have forwarded me this paper, Identification of common variants associated with human hippocampal and intracranial volumes:

…Whereas many brain imaging phenotypes are highly heritable…identifying and replicating genetic influences has been difficult, as small effects and the high costs of magnetic resonance imaging (MRI) have led to underpowered studies. Here we report genome-wide association meta-analyses and replication for mean bilateral hippocampal, total brain and intracranial volumes from a large multinational consortium. The intergenic variant rs7294919 was associated with hippocampal volume (12q24.22; N = 21,151; P = 6.70 × 10−16) and the expression levels of the positional candidate gene TESC in brain tissue. Additionally, rs10784502, located within HMGA2, was associated with intracranial volume (12q14.3; N = 15,782; P = 1.12 × 10−12). We also identified a suggestive association with total brain volume at rs10494373 within DDR2 (1q23.3; N = 6,500; P = 5.81 × 10−7).

Look at the sample sizes. Beware of behavior genomics with small sample sizes. Paul Thompson, one of the many authors of this paper, is giving media interviews. To me that’s a good sign, as he’s a very smart guy. He has some confidence in this study. Here’s the section which is resulting in the forwards:

… In addition, the C allele of rs10784502 is associated, on average, with 9,006.7 mm3 larger intracranial volume, or 0.58% of intracranial volume per risk allele and is weakly associated with increased general intelligence by approximately 1.29 IQ points per allele.

I’m a homozygote for the T allele for what it’s worth. But that’s not surprising. Look at the population distribution of the C allele from the HapMap:

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I don’t have time to do a detailed analysis of my group selection survey right now. So I’ve uploaded the raw results for anyone to play with (there is no personally identifying information obviously). You should be able to convert it into an appropriate format for R or something else pretty easily.

In a follow up to a post below, a new paper in PLoS Genetics has some data on American Hispanics. Specifically, Puerto Ricans, Dominicans, Mexicans, and Cubans, as well as assorted Central and South Americans. I am not too interested in the cases except Cubans; no one doubts the mixed heritage of the other groups, though the African ancestry of Mexicans, and some Central and South Americans may surprise (again, I have to note that this not surprising in light of history, and has been robustly confirmed in the genomic literature).

But Cuban Americans are somewhat a special case. The vast majority, specifically, 85 percent, identify as white. This is a higher proportion than the number of self-identified whites in Cuba, and a function of the skewed nature of the migration out of Cuba socially and economically. By and large the white elite of the island fled Castro’s revolution to a far greater extent than the black lower classes. And contrary to American stereotypes of Latin American ease and openness about race, Cuba was a relatively stratified society, albeit not characterized by hypodescent. Slavery was not abolished on the island until 1884. Additionally, Cuba did experience a relatively large wave of Spanish immigration in the early 20th century. I have taken the claims of “pure Spanish ancestry” on face value in the past because of this history. But further genomic evidence makes me reconsider the biases in the reporting of ancestry. For example, I have heard singer Gloria Estefan mention that her heritage was of recent Spanish immigrants from Cuba, but Wikipedia indicates that this is the origin of her maternal lineage. It leaves her paternal lineage unaccounted for. I have no doubt that her father’s family were white Cubans, but if their roots on the island were somewhat deep, I am also sure that they had non-trivial African, and possibly Amerindian, ancestry.

The reason for some of these assertions from are the genomic results, like figure below from the paper mentioned above (reedited for some clarity and specificity).

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A few days ago I was contacted by Microzyra, a Seattle based start-up. Their aim is do for science what Kickstarter has done for creative projects. Obviously I can’t vouch for them, but I am intrigued enough to eventually consider seeing if I can raise funds through this avenue once I have some time for the Afrikaner genotyping project that I have in mind.

Update: Also see Petridish.org.

A few years ago I put up a post, WORDSUM & IQ & the correlation, as a “reference” post. Basically if anyone objected to using WORDSUM, a variable in the General Social Survey, then I would point to that post and observe that the correlation between WORDSUM and general intelligence is 0.71. That makes sense, since WORDSUM is a vocabulary test, and verbal fluency is well correlated with intelligence.

But I realized over the years I’ve posted many posts using the GSS and WORDSUM, but never explicitly laid out the distribution of WORDSUM scores, which range from 0 (0 out of 10) to 10 (10 out of 10). I’ve used categories like “stupid, interval 0-4,” but often only mentioned the percentiles in the comments after prompting from a reader. This post is to fix that problem forever, and will serve as a reference for the future.

First, please keep in mind that I limited the sample to the year 2000 and later. The N is ~7,000, but far lower for some of variables crossed. Therefore, I invite you to replicate my results. After the charts I will list all the variables, so if you care you should be able to replicate displaying all the sample sizes in ~10 minutes. I am also going to attach a csv file with the raw table data. As for the charts, they are simple.

– The x-axis is a WORDSUM category, ranging from 0 to 10

– The y-axis is the percent of a given demographic class who received that score. I’ve labelled some of them where the chart doesn’t get too busy

All of the charts have a line which represents the total population in the sample (“All”).

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Until a few years ago if I had to use MS Office, I used Office 97. I’ve been using Open Office and its precursors going back to 2000, but sometimes people really want MS format, and the export and “save as” features of Open Office don’t always work the best.* Now that I have upgraded to the new Word I really miss the old version. I thought that was due to my huge gap in usage, as what was a gradual shift seemed like a radical rupture to me. This indicates I’m wrong:

I know only one person who loves working in Word: my 4-year-old. It’s valuable to him to be able to put the names of subway lines in their correct colors, or to spell out “autumn” with each letter a different falling-leaf hue, or to jump from Times New Roman to Comic Sans to Chalkboard in midstory. He also loves to write things on my old manual Smith-Corona. A tool that’s lost its purpose makes a great toy.

* I’m in Linux a fair amount too, so it often isn’t an option.

Many people say that having children gives you a much better sense of the power of genes in shaping behavior. At least in the abstract sense that is not true in my case. I accept the “conventional wisdom” from behavior genetics that “shared environment” (colloquially, parental input) is relatively marginal in effecting much long term change within reason (i.e., if you don’t beat your kid over the head with a baseball bat and such you don’t have much influence).

To review, on many bio-behavioral traits the different choices parents make seem to account for on the order of ~10 percent of the differences you see in the world out there amongst their (biological) offspring. Of the remainder of the variation about half of it is attributable to variation in genes, and the other half to unaccounted for non-shared environment. In The Nurture Assumption Judith Rich Harris proposes that that last effect can be reduced down to social environment or peer groups. Her line of argument is such that parents are important because of the genes they contribute, and, the environmental milieus which they select for their offspring.

On one level I find this banal to review. If it is not the orthodoxy, this position seems relatively uncontroversial, and the results fall out of the data with minimal manipulation. But as a society such facts have simply not been internalized. In the great framing of “nature vs. nurture,” appealing in its stylistic dichotomy, but not even wrong in its substance, the past few centuries have seen multiple swings between each stylized extreme. That has been a matter of ideology, not science. The popularity of public intellectuals such as Steven Pinker by the turn of the 20th century indicates to me that the high tide of post-World War II nurture-über alles has receded. But the media and popular culture are to some extent lagging indicators. They continue to trumpet correlations between parental choices and offspring outcomes as if there is a causal connection without pausing to consider the possibility both might be being influenced by a confound, genes.

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PLoS ONE has another article up about admixture in Argentina. The interesting aspect is that in its self-conception Argentina, like the United States of America or Australia, is a European settler nation, and therefore unlike Mexico, Boliva, or Brazil, each of whom de jure or de facto espouse a multicultural and multiracial identity. Buenos Ares is in its mentality more a Southern European city situated in the antipodes, with a touch of old Mitteleuropa (Argentines are avid consumers of psychoanalysis). As noted in the PLoS article, ~1 percent of the citizens of Argentina identify as indigenous, but ~20 percent of the ancestry of Argentina’s population seems to derive from Amerindian sources! The paper itself adds little new here. Rather, it increases the sample size, and confirms that the Amerindian ancestry does seem to be lower in Buenos Ares, the magnet for so much Italian immigration.

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Most of you have probably seen this stylized graphic somewhere along the away (I think it was on PBS at some point). But it’s still cool….

I found out today that a private equity firm has purchased the majority of the Yellow Pages from AT&T. Which prompts me to ask: when was the last time you used the yellow pages? A pay phone? In a similar vein, Google And The Death Of Getting Lost. In 10 years (2001 to 2011) wireless penetration in the USA went from ~40 percent to ~100 percent.* This is the difference between arranging a rendezvous ahead of time in precise detail, and being confident that you can just end it with “I’ll call you.”

Image credit: Wikipedia

* This is actually calculated by comparing the number of phones to people. Since some people have multiple phones, and businesses purchase them for their employees, “real” penetration is somewhat less than this. I suspect that it is a larger underestimate for 2001, as a larger proportion of phones were probably business-related.