Dienekes points to a paper by Yann, Estimating Genetic Ancestry Proportions from Faces:
Ethnicity can be a means by which people identify themselves and others. This type of identification mediates many kinds of social interactions and may reflect adaptations to a long history of group living in humans. Recent admixture in the US between groups from different continents, and the historically strong emphasis on phenotypic differences between members of these groups, presents an opportunity to examine the degree of concordance between estimates of group membership based on genetic markers and on visually-based estimates of facial features. We first measured the degree of Native American, European, African and East Asian genetic admixture in a sample of 14 self-identified Hispanic individuals, chosen to cover a broad range of Native American and European genetic admixture proportions. We showed frontal and side-view photographs of the 14 individuals to 241 subjects living in New Mexico, and asked them to estimate the degree of NA admixture for each individual. We assess the overall concordance for each observer based on an aggregated measure of the difference between the observer and the genetic estimates. We find that observers reach a significantly higher degree of concordance than expected by chance, and that the degree of concordance as well as the direction of the discrepancy in estimates differs based on the ethnicity of the observer, but not on the observers' age or sex. This study highlights the potentially high degree of discordance between physical appearance and genetic measures of ethnicity, as well as how perceptions of ethnic affiliation are context-specific. We compare our findings to those of previous studies and discuss their implications.
At this point ancestrally informative markers are rather powerful and precise. You can ascertain whether someone is a half-Jew or full-Jew, or Uyghur. That's the genetic reality. Population substructure is reflected in the patterns of genetic variation, which map onto preexistent geographically derived categorizations.
But racial categories are also social constructions, and the correlation between total genome content and salient phenotypes which we use to "code" racial identity is imperfect. This is why fraternal twins can be categorized as separate races, and subjectivity results in different individuals coding the same individual differently.
This study uses 14 individuals of "Hispanic" background because to a great extent this relatively new constructed category in the United States is of hybrid origin. This results in a very high level of extant phenotypic (and presumably genotypic) variance within the group. If genes map onto appearance one would expect a rough correspondence between ancestral blood quanta and phenotype. There seems to be such a thing for African Americans; the more white ancestry one has, the more white characteristics one has. In this sample individuals with more Native American ancestry should be more Native American in appearance, and outside observers should note this. What did they find?
The solid line shows the estimates that the observers should have made if they randomly guessed how much Native American ancestor any of the 14 Hispanics had. The further the right, the greater the error. As you can see the observers guessed better than random; this suggests that there was a correlation between appearance and ancestry. There is something interesting in the pattern of how the observers made errors though....
The confidence intervals are big for Native Americans, but here you see that observers who were non-Hispanic white overestimated Native American ancestry, and Native Americans underestimated it. This goes to what I have alluded to multiple times: there is a subjective weighting in the importance of various characters which results in one's perception of someone's racial identity.
But there's something else that's important here in the paper:
This study shows that the degree of concordance between genetic and observer estimated Native American ancestry proportions for individuals in this sample of New Mexicans is slightly but significantly higher than if observers were to estimate randomly. The error in estimation by the observers (6.07) is much closer to random estimation (7.49) than it is to perfect estimation (0.36), suggesting either that facial features are not perfectly reliable indicators of ancestry as was shown in Brazil...or that individuals are not very closely attuned to the phenotypic cues of group differences. We discuss our findings, relate them to previous findings, and discuss their implications regarding human social behavior.
Though it seems that there was some ability to estimate ancestry based on appearance, the correspondence between blood quanta and appearance does not seem particularly high. The paper goes on to clarify why this might be:
These results also have implications when considering the history of admixture, sexual selection, and the genetics of complex traits. For example, it may be that after several generations of sexual selection for facial appearance, the genetic variants that are responsible for those traits would no longer be in linkage disequilibrium with other population-specific genetic variants...This process would result in dissociation between these traits and the estimate of genetic admixture for the rest of the genome. Depending on their specific history, populations differ in how they are stratified with respect to admixture. This will affect the strength of the correlation between genetic admixture estimated from genetic markers scattered throughout the genome and any phenotypes that differ between parental populations. Factors such as a long time since initial admixture, non-continuous gene flow, and assortative mating will decrease the degree of admixture stratification, and hence the relationship between overall admixture and phenotypes that are different between parental populations and that are controlled by just a few loci....
Over the past few years there have been several cases of black & white twins. That is full-siblings who favor one parent over another in appearance to the point where one would naively classify them as racially distinct. If it happens that in the future the white halves of these dyads pair up with each other, and the black halves with each other, their offspring will all be about ~50% African and ~50% European, but likely to an outsider it would be as if there are two distinct populations here. This is an extreme case, but it illustrates the general principle.
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This is really interesting, Razib- but it deals with more or less "random" residents of New Mexico. Trained anthropologists can identify someone's background by physical features with a much higher degree of accuracy, but there will always be some people for whom the phrase "Funny, you don't LOOK _____" applies.
I'm a little unclear as to what the key point of this post is- you're saying that facial features aren't the best way of identifying background, not that the inability of some to identify background based on facial features proves the current PC meme that "there's no such thing as race", right?
but it deals with more or less "random" residents of New Mexico.
not totally. there were university students too.
you're saying that facial features aren't the best way of identifying background,
in some contexts they aren't, in some they are. the authors point out that self-report of identity and genetic data match almost perfectly in some groups. in others, such as mestizo latinos, the self-report is far less informative (there might be a big diff. in disease susceptibility between someone who is 1/4 NA and 3/4), and physical appearance will have to substitute. brazil is a case which shows this more clearly, as even trained anthropologists would be confounded in enough cases.
I guess what I'm trying to say is "what is the big picture" of this study and this post?
Is "facial features aren't always reliable at determining someone's ethnic background" the main message here or is this meant as evidence towards a large point about race?
For example, I've seen a lot of people lately- even just today on my own blog- that claim that scientifically there's no such thing as race.
that claim that scientifically there's no such thing as race.
i don't agree with that.
Sigh...Trust me, it's not worth bothering with that conversation if you don't VERY specifically agree on consistent terminology at the outset. Semantic arguments are less illuminating than data.
This was a good article: http://scienceblogs.com/gnxp/2009/01/of_clines_and_clusters.php
"scientifically there's no such thing as race": wishful thinking doesn't count as science.
Hi Razib,
I linked to your blog from your comments over at the Denialism blog. You sounded interesting and I find this post stimulating.
At the afore mentioned blog you stated that you were a mild social retard, I also suffer from a low E.Q. so if I come off as an arrogant a-hole apologies in advance. Remember it isnât nice to hate people with disabilities.
As bored as I am with the whole topic of racial differences I was intrigued by the âsciencyâ nature of the research you referenced in your post. As a guy pursuing an advanced degree in physics I was a bit unimpressed with the attempt to mathematically quantify and correlate racial genetic markers with the perceptions of âraciallyâ sorted observers.
Kind of like quantifying the perceived âfunkinessâ of hip hop music by a pre-selected subset of âurban youthâ as compared to a mathematical musical model of said musical piece as determined by a computer based âfunkâ algorithm.
Iâm sure such a study could be undertaken and that âsciencyâ looking graphs and tables could be generated but Iâm equally sure that nothing scientifically meaningful could be sifted from the hopelessly subjective and unverifiable observations and data.
In my opinion, formulated over two beers and by reading only the excerpts of the study you provided and your commentary, the racial study you quote suffers from the same hopelessly subjective and empirically unverifiable faults as my proposed âhip hopâ study.
That said my (Amhara tribal ancestry) wife is quite adroit at determining the ethnic (tribal as she describes it) identity of Ethiopians by their subtle facial features. At least she thinks so. In my admittedly anecdotal observation of her abilities in this area I would say that she is better than 50/50 but less than 75/25 in identifying the âtribeâ of these individuals. I doubt a detailed study of the genetic markers of these people and the subjective opinions of a random sample of a group of âobserversâ would identify anything more remarkable than the fact that people that have a history of group association are able to recognize the facial features of their close neighbors better than people that see them as just so many âblack peopleâ.
Hardly a surprising result!
âRaceâ is crap as far as science is concerned. Now politically and socially it sadly has very real consequences even if people have no ability to scientifically define it.
By the way you look âIndo-Pakistaniâ to this subject. Was I close? Do I get to be on a fancy graph?
. I doubt a detailed study of the genetic markers of these people and the subjective opinions of a random sample of a group of âobserversâ would identify anything more remarkable than the fact that people that have a history of group association are able to recognize the facial features of their close neighbors better than people that see them as just so many âblack people
depending on the level of inbreeding (barriers to gene flow) there might be non-trivial differences. this particular study had a specific aim, attempting to ascertain the accuracy of perceptions as they relate to ancestry. this might interest you more:
jew vs. non-jew
genetic map of europe
genetic map of east asia
other genetic maps
if the measure of precision and accuracy you expect is what one might find in physics, then there are no other sciences besides physics.
also, here's an older paper, but it gets to he heart of the matter.
Razib,
Sorry that your blog-ware hates my quote marks. Ill be omitting apostrophes as well so bear with my grammatically challenged response. It looks like I use them too much based on my last jagged post.(Maybe its the beer.)
I started out (many years ago) as an aspiring geneticist so I am quite comfortable with the idea that what we are is largely a function of our genetic make-up. I just don't know if you can put meaningful lines around any phenotypical or genotypical markers that can be identified as race.
Apparently, from your previous remarks, you disagree. Since you obviously have a greater knowledge of genetics than I do Ill assume you have a rational basis for that opinion.
Then again it may stem from a semantic difference on our use of the word race.
I appreciate your thoughtful response and I'll be hitting those links tomorrow. The meest-ee-yea (thats phonetic Amharic for wifie dear) gets off work in 30 minutes and I told her Id pick up Taco Bell.
Nice to meet you.
I just don't know if you can put meaningful lines around any phenotypical or genotypical markers that can be identified as race.
i don't draw lines, i assert odds :-)
I told her Id pick up Taco Bell.
you'll regret that an hour after you eat it.
My granddaughter:
Surname - Spanish
Racial/etnic/whatever makeup:
9/16 Scots-Irish-English-French
3/8 Filipino
1/16 Native American (Cherokee)
I have witnessed at least three times when Filipinos approach my daughter (without her husband present) and ask, with relative assurance of the answer, whether her child is Filipino. One dear Filipino lady actually proposed that her son should be considered a future mate, though somewhat jokingly. He was a very cute kid.
Through several years of association with my daughter's in-laws, I have found that I too can now differentiate between Japanese, Chinese, and Filipino. Strange, no?
My 3/4 Filipino son-in-law is often mistaken in certain parts of the country for Arab/ME background unless he is wearing his Filipino (best described as subdued Hawaiian) garb or his U.S. Army uniform. In New Mexico and Arizona, he is never mistaken for Mexican, though he often was in Virginia (where, at age 35, he said felt discriminated against for the first time in his life).
Socially, my Filipino son-in-law is a redneck. He collects guns, takes his mother-in-law to the range so she can shoot his Polish AK-47, rides Harleys, hunts, and fishes.
My actual Presbyterian redneck son-in-law prefers to play golf. My Irish-Catholic son-in-law likes beer and making money. Beer is their common denominator... which my Korean step-son embraces.
In reality, what they all share is military experience. They are all products of the U.S. Army and Air Force. None of them mess (too much) with their Marine Corps father-in-law.
One of the joys of shopping at the commissary is the variety of ethnic foods available. Perhaps our military has more to teach us than we might think?
I'm also amused at the the recent genealogy consanguinity stuff I've been reading and how this applies here -- ie, the consanguinity of double cousins and the offspring of identical twins where the father is the same and the offspring of fraternal twins where the father is the same.
Fascinating stuff, eh?
Hispanic is not a race. Jew is not a race, Jew are ethnoreligious. I just wanted to make that clear. Thank You.