our political nature and human biodiversity

just started reading avi tuschman‘s Our Political Nature: The Evolutionary Origins of What Divides Us. so far it’s very good! mind you, i’ve only read the first two chapters (there are twenty-three altogether). (~_^)

according to tuschman, his goal in writing this book is [from the preface – my emphasis]:

“[T]o paint a compelling and accurate portrait of our nature as political animals. Today’s political commentators would have us believe that we vote based on our views about the main issues of the day, on our economic circumstances, or on our longtime affiliations with this political party or that. That’s wrong, or at least incomplete. Step by step, I will explain that our political orientations are not simply intellectual constructs, flowing from our upbringing, our schooling, our peer groups, or which newspapers we read. No, our political orientations are actually natural dispositions, molded within each of us by powerful evolutionary forces.


in the first two chapters, tuschman reviews some of the major research out there which has found that personality is largely innate and that personality strongly influences our political orientations (left-wing or right): the blocks’ study showing that personality at age four strongly correlates with political orientation as an adult (in one’s 20s) [pdf], for example, and alford et al.’s twin studies which showed that identical twins reared apart have very much the same political orientations [pdf], and so on.

well, he doesn’t need to persuade me! (~_^) left and right — we are “born this way.”

furthermore, tuschman says we’ll find these innate left/right personalities in all societies. he draws, though, what i think is a slightly awkward comparison between all of the rebellious folks in the arab spring and the occupy wall street movement in the western world [chapter 1]:

“[I]t was precisely Basboosa’s [the tunisian man who immolated himself triggering the so-called arab spring] moral *rejection of inequality* that activated one of these universal hot buttons residing within him, and within so many of his compatriots. And this is why his story resonated with a critical mass of people in the Middle East, for whom Basboosa symbolized the humble, well-meaning common man systematically abused by government fiat and corruption.

“Now, the story of Basboosa might seem rather remote to many American readers. But the same hidden trigger at play in the Middle East underlies the concurrent transformation of the political landscape in the United States. As the Arab Spring was unfolding, the ‘Occupy Wall Street’ movement emerged on the far left of the US spectrum. The demonstrators in New York shouting, ‘We are the 99 percent!’ were railing not against Middle Eastern dictators, but rather against bankers and large corporations. And yet the same issue that ignited the Arab Spring had inspired and galvanized their movement: a moral rejection of economic and social *inequality*.”

well, yeah … sort of … maybe. but i’m not certain that there are equally as many individuals in tunisia — or north africa — concerned about equality for everybody as there are in the united states or western europe. there might be a lot of people p*ssed off in the arab world/middle east/north africa that they, personally, experience so much corruption in their daily lives and that they and their families are often cheated by others, but are they really morally rejecting economic and social inequality to the same degree that, say, a swede does? i dunno, but it’s worth asking.

just looking quickly at one set of responses from the world values survey [1981-2002 waves] to the question…

“How would you place your views on this scale? – Incomes should be made more equal vs We need larger income differences as incentives.”

…we find that north africans are very much for GREATER income inequality [click on chart for LARGER view]:

wvs - income equality

i think it would be very safe to bet that different populations will vary not only in the numbers/proportions of leftists vs. rightists found within them but also in how liberal or conservative their left- or right-wingers are.

but i think i’m getting ahead of tuschman and that he’s actually going to get to this later in the book. for instance, in chapter two, he does say:

“What happened when groups of very different genetic backgrounds live in the same environment? In this case, each group’s average personality scores differed according to the *origin of their ancestors*. For example, the personality traits of white South Africans clustered closer to the Swiss, while black South Africans had personalities more similar to Zimbabweans. Likewise, groups that have traditionally lived in geographically adjacent territories have more similar average personalities than groups separated by large distances.”

so i should prolly finish reading the book before i say any more on this. (^_^)

previously: well this sounds familiar…

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the outbreeding project continues apace…

…in the united states! (just as you all suspected.) amongst white folks anyway (that’s who was included in the study below).

from a study published in 2009, Measures of Autozygosity in Decline: Globalization, Urbanization, and Its Implications for Medical Genetics:

This research has definitively shown the existence of a trend for decreasing autozygosity with younger chronological age in the North American population of European ancestry. The ROHs we identified, larger than 1 Mb, are clearly representative of autozygosity due to distant consanguinity in our outbred populations, and not chromosomal abnormalities or common copy number variants. Using our predictive models of decreasing Fld, we show a quantifiable decrease in consanguinity over the twentieth century. Based on data provided in Carothers et al, this decrease in Fld found in our discovery population is on the order of individuals transitioning from a single inbreeding loop 4–5 generations prior, to no inbreeding loops within <6 generations. We postulate that the increased mobility, urbanization and outbreeding in North America in the last century has led to less consanguinity (and thus less homozygosity and homogeneity) in younger individuals.”

the researchers looked at two different sets of genomes — one from the ninds repository @the coriell institute, the other from the baltimore longitudinal study of aging (blsa). the blsa is, obviously, biased towards people on the east coast of the u.s. (in and around baltimore). glancing through the list of submitters to ninds, there’s also something of an east coast bias there, although many samples do come from other areas of the country (see the list of locations at the end of this post).

amongst the findings in this study are that 1) the number of runs of homozygosity (roh) has decreased in white americans over the last one hundred years or so, and 2) the lengths of the roh have shrunk as well. both of these are good indicators of outbreeding.

here are a couple of tables/charts from the paper (click on images for LARGER views):

measures of autozygosity in decline - table 02

measures of autozygosity in decline - percent of genome in roh

what’s interesting to contemplate, i think, is what this might mean wrt selection pressures on americans going forward? especially, what might it mean in light of european-americans encountering other, newer groups within american society that are not outbreeding so much (at least not at the moment) — newly arrived immigrants from many muslim countries, for example — or even, perhaps, latin americans (although i’m not 100% sure about how much they’ve been inbreeding over the past few hundred years or so — stay tuned!). how is that all going to play out? interesting times.

possibly related footnote — here is an abstract from the 2013 ashg conference:

“Reconstructing the Genetic Demography of the United States”

“The United States (U.S) is a complex, multiethnic society shaped by immigration and admixture, but the extent to which these forces influence the overall population genetic structure of the U.S is unknown. We utilized self-reported ancestry data collected from the decennial U.S Census 2010 and allele frequency data from over 2000 SNPs for over 40 of the most common ancestries in the U.S. that were available from the Pan Asian Single Nucleotide Polymorphism (PASNP), Population Reference Sample (POPRES), 1000 Genomes, and Human Genome Diversity Panel (HGDP) databases. We utilized the relative proportions of individuals of each ancestry within each county, state, region and nation and calculate the weighted average allele frequency in these areas. We reconstructed the genetic demography of the U.S by examining the geographic distribution of Wright’s Fst. Shannon’s diversity index, H was calculated to assess the apportionment of genetic diversity at the county, state, regional and national level. This analysis was repeated stratifying by race/ethnicity. We analyzed households with spouses, using the phi-coefficient as a measure of assortative mating for ancestry. This analysis was repeated stratifying by age of the spouses (older or younger than 50). Most of the genetic diversity is between ancestries within county, but this varies by race/ethnicity, and ranges from 95% for Whites to 43% for Hispanics illustrating that the White ancestries are relatively homogeneously scattered throughout the U.S whereas the Hispanic ancestries show significant clustering by geography. Analysis of the mating patterns show strong within ethnicity assortative mating for American Indian/Alaska Natives, Asians, Blacks, Hispanic, Native Hawaiians/Pacific Islanders, and Whites, with φ = 0.30, 0.864, 0.92, 0.863, 0.478 and 0.832 respectively (P<1×10-324 for each) and significantly less correlation in the younger cohort. These results show demographic patterns of social homogamy which are slowly decreasing over time. One major implication is that data collected from different locations around the U.S are susceptible to both within- and between-location population genetic substructure, leading to potential biases in population-based association studies.”

origin cities of the ninds samples (from a quick-ish glance):

Burlington, VT
Lebanon, NH
Boston x 10
New York x 7
Rochester, NY x 4
New Haven x 3

Bethesda x 7
Baltimore x 5
Washington, D.C.

Winston-Salem, NC
Charleston, SC

Birmingham x 3

Jacksonville x 4

Cincinnati x 5
Indianapolis, IN
Ann Arbor

Chicago x 3
Springfield, IL
Rochester, MN
Englewood, CO
Kansas City

Houston x 4

Salt Lake City

Los Angeles
Irvine, CA
Fountain Valley, CA
San Diego x 2
San Francisco x 3

previously: runs of homozygosity and inbreeding (and outbreeding) and runs of homozygosity in the irish population and western europeans, runs of homozygosity (roh), and outbreeding and russians, eastern europeans, runs of homozygosity (roh), and inbreeding

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