January 10, 2013

Blue eyes, facial shape, and perceived trustworthiness

A new paper suggests that Czechs tend to view brown-eyed people as more trustworthy than blue-eyed ones, although the difference seems to be due to differences in facial structure between brown- and blue-eyed people; an article in Scientific American covers this new paper fairly well.

I will add that the location of the sample (Czech Republic) is interesting, as it is intermediate between the Baltic area (where light eye pigmentation reaches quasi-fixation, and, hence, presumably, light eyes are not viewed with any suspicion) and southeastern Europe and Anatolia (where there is well-documented folklore about the association of eye pigmentation with the "evil eye").

I had encountered an explanation for this phenomenon in a work by P.G. Maxwell-Stuart on ancient color terminology, in which an argument was made that in predominantly dark-eyed peoples, light eyes -because of their rarity- may have an indirect association with glaucoma and viewed suspiciously for that reason -perceived chance of morbidity; the Wikipedia article suggests the phenomenon is explained on the basis of encounters with light-eyed foreigners who might be unaware of cultural norms against direct staring. But, the frequency of different eye colors in Czechs today is probably fairly balanced, making either explanation unsatisfactory.

Getting back to the article at hand, it appears that -at least in men- blue eyes are associated with a suite of other facial features. Razib offers the suggestion that the possible disadvantage conferred by reduced "trustworthiness" may be compensated in another way through pleiotropy, and the authors suggest:
The trade-off between a preference for colorful and visible physical features and the advantage of a trustworthy-looking face might have contributed to the high variability of European eye and hair color.
But, I'll get back to the possibility that the phenomenon may be driven by a historical process, i.e., the encounter between peoples who differed statistically in eye pigmentation and other facial features.

The picture on the left is from the Gospel Book of Otto III and is about 1,000 years old. Now, all eyes appear conventionally painted as brown dots here, but we can notice that the different provinces are painted with different hair color, with Sclavinia being darker than Germania and lighter than Gallia and Roma. This might make some sense, since Germanic peoples are thought to have originated in northern Germany/southern Scandinavia, and Slavs in C/E Europe (perhaps somewhere between Poland and Ukraine).

This raises the possibility that early Slavs were phenotypically somewhere in the middle of the European pigmentation continuum, although their exact position therein might only be determined with ancient DNA evidence. Today, the lighter-pigmented Slavs are probably those close to the Baltic (e.g., Russians and Poles), the darker ones from the Balkans, perhaps indicating different types of gene flow ("northern" Germanic/Baltic/Finno-Ugrian vs. "southern" Thraco-Illyrian-Greek).

If this is correct, then the slightly negative association of blue eyes in the present Czechs might be a culturally-transmitted vestige of inter-ethnic contact during the medieval period. A possible test would be to repeat the experiment with the Czechs' German neighbors, in which the process ought to operate in reverse -if my hypothesis is correct.

PLoS ONE 8(1): e53285. doi:10.1371/journal.pone.0053285

Trustworthy-Looking Face Meets Brown Eyes

Karel Kleisner et al.

We tested whether eye color influences perception of trustworthiness. Facial photographs of 40 female and 40 male students were rated for perceived trustworthiness. Eye color had a significant effect, the brown-eyed faces being perceived as more trustworthy than the blue-eyed ones. Geometric morphometrics, however, revealed significant correlations between eye color and face shape. Thus, face shape likewise had a significant effect on perceived trustworthiness but only for male faces, the effect for female faces not being significant. To determine whether perception of trustworthiness was being influenced primarily by eye color or by face shape, we recolored the eyes on the same male facial photos and repeated the test procedure. Eye color now had no effect on perceived trustworthiness. We concluded that although the brown-eyed faces were perceived as more trustworthy than the blue-eyed ones, it was not brown eye color per se that caused the stronger perception of trustworthiness but rather the facial features associated with brown eyes.

Link

25 comments:

Onur said...

The average facial features of the brown-eyed individuals analyzed in this study are more distinctively Caucasoid than the average facial features of the blue-eyed individuals analyzed in this study. This correlates with the ADMIXTOOLS and TreeMix results of Caucasoids (according to which northern Caucasoids have more overall Mongoloid admixture than southern Caucasoids), as the proportion of blue eyes increases and the proportion of brown eyes decreases moving from south to north among Caucasoids.

Fanty said...

@Onur:

So you think this is about northern Europeans beeing more Mesolithic phenotypically with all these pre-neolithic relict phenotypes like Brünn, Trönder, Faelid, Borreby, Baltid, wich are all more wide faced than those supersexy looking neolithic faces like Nordid, Atlantid, Mediteranid and Pontid?

And wide faced males are more likely to use physical violence or to cheat, break rules, become criminal etc. While, a little bit contradictary, wide faced males are also the ones who develop more loyality to the group and are more ready to sacrifice themselfs if the existance of the group is in danger.

And, blue eyes and blond hair are most likely from mesolithic Europeans rather than neolithic migrants originally? So, Ogre faced blond blue eyed northern European vesus brown haired and brown eyed, Elven faced neolitic migrant? ;)

__ ROB __ said...

Trustworthiness in blue eyed Scandinavians: http://news.google.com/newspapers?nid=1683&dat=19960620&id=UikzAAAAIBAJ&sjid=5S0EAAAAIBAJ&pg=6767,7131498

Onur said...

Fanty,

I think that we will give more conclusive answers to the questions you raised over time with the increasing numbers of whole genome and ancient DNA analyses. What is of more importance for me, at least over the short term, is asking questions that are never or rarely asked and discussing subjects that are never or rarely discussed rather than answering questions.

Fanty said...

Hm.

Well, I am German.
I dont know about a study/paper about this topic but I know the usual stereotypes.

Blue Eyes:
Gentle, kind, innocent, loyal, introverted

Grey eyes:
Callous, determined, calculating

Green Eyes:
Evil, back stabbing, witch

Brown Eyes:
Emotional, Impassionade, extroverted

hamarfox said...

This correlates with the ADMIXTOOLS and TreeMix results of Caucasoids (according to which northern Caucasoids have more overall Mongoloid admixture than southern Caucasoids)

At this point, you're pretty much a broken record. The latest paper on the subject shows negligible intra-Caucasoid differences in levels of North Eurasian admixture, as you already know and would accept if you didn't have some ulterior motive, which has been obvious to me for some time now.

There's a difference of a few percent between Northern and Southern Europeans, which explains the trends Dienekes spotted over a year ago. But considering the recent insights into the admixture (i.e. Lipson et al.), an unbiased mind would accept that levels seem to be ~25% across the board (including in non-European Caucasoids).

You can't pick and choose which statistics to accept. You accept Patterson et al's initial finding, but don't accept his (i.e. the same team's) later revision of said finding. Why? I don't know, but whatever the reason is, it's obviously not scientific.

Onur said...

Hamar,

You seem to be hasty and careless in judging people. I pointed to a correlation between the facial feature results of this study and the genetic analysis results of ADMIXTOOLS and TreeMix, but did not make a definitive statement on that. Another point, a successor analysis method is not always more accurate than a precursor one.

I could make the same criticism against you that you make against me, but in discussions I direct all my attention to arguments themselves, and I abstain from pointing to motives behind people expressing opposing arguments as much as I can, as that usually does harm to discussions.

Gregory76 said...

Onur said:
The average facial features of the brown-eyed individuals analyzed in this study are more distinctively Caucasoid than the average facial features of the blue-eyed individuals analyzed in this study.
Then Fanty interpreted this as follows:

So you think this is about northern Europeans beeing more Mesolithic phenotypically with all these pre-neolithic relict phenotypes like Brünn, Trönder, Faelid, Borreby, Baltid, wich are all more wide faced than those supersexy looking neolithic faces like Nordid, Atlantid, Mediteranid and Pontid?
To me it seems that the descriptions given seem to imply the reverse interpretation. The blue-eyed men seem to have features of the narrow headed, narrow faced, slender Nordic/Mediterranean type (the Neolithic type): having a narrower mouth, a longer chin, and lower faces that are more prominent, as well as “more distant eyebrows” (if this entails that they are smaller), fits with this type more than the Mesolithic type, and, to a lesser extent, so do angular faces, and smaller eyes, while the brown-eyed men seem to have features of the broader-headed, broader-faced, huskier Borreby/Brunn and East Baltic/Neo-Danubian type (the Paleolithic type) and the Alpine type (which may be of more recent origin): bigger mouth, broader chin, and more prominent eyebrows, and bigger noses (insofar as they are bigger because they are wider, though not insofar as they are bigger because they are longer).
As to the Mongoloids, the latter types seem to have more in common with them than the former types do.
I would have expected the opposite, with the blue-eyed men being East Baltic/Neo-Danubian, as is common in northeastern Europe, and the brown-eyed men being Dinaric, as is common in southeast Europe. Instead, this paints the blue-eyes as Nordic and the brown-eyes as, perhaps, a version of Alpine.
However, looking back at the related 2010 study, the facial composites of the blued-eyed men and the brown-eyed each show a mixture of features from both groups.

Fanty said...

"while the brown-eyed men seem to have features of the broader-headed, broader-faced, huskier Borreby/Brunn and East Baltic/Neo-Danubian type (the Paleolithic type)"

Well, no.
"Nordid" is a minority EVERYWHERE. Even in Sweden there is only 7% "Nordid" people. (4% in Germany)

"Borreby" is the standart human of Northern Germany and Denmark and some maps show it right. Its a myth, that "Nordid" is the standart human of Scandinavia.

1940 descriptions describe the "tyical" pigmentation in Germans like this:


Nordid (northern half of Germany from Dutch border to Russian border): Goldblond and blue eyed

Borreby (limited to North West Germany): Redblond and blue eyed (technically what Tacitus describes for Germanic people)

Baltid: White/Silver blond and grey eyed

Alpinid: (Southern half of Germany) brown haired and brown eyed

A Nordid is simply a neolithic farmer from Spain who mixed with native Borrebys and got blond and blue eyed in the process and its a MINORITY. The anchestors of that "Nordid" came black haired and black eyed to Scandinavia, I am almost sure about this. ;)


Fanty said...

"Alpine type (which may be of more recent origin)"

Of course. Metal age.

In my Opinion:

Native/Mesolithic hunter gatherer North/Central: Borreby
depigmented neolithic farmer: Nordid
Bronce Age arrival: Alpinid

aspromavro said...

The explanation is probably quite simple: Slavs tend to view Germans with suspicion. Hence, the less you look like a German, the more trustworthy you are perceived to be.

hamarfox said...

Hamar,

You seem to be hasty and careless in judging people.


Well, not exactly. I've been in numerous discussions with you about this, and my above conclusion is based on the inflexability of your narrative on the issue. Regardless of the progress made in previous debates, you re-enter each topic as though no counterpoints had ever been made. For example, you don't even state that this element may be Mongoloid, but state each time that it is.

I pointed to a correlation between the facial feature results of this study and the genetic analysis results of ADMIXTOOLS and TreeMix, but did not make a definitive statement on that.

There are multiple connections to be made: First, that the blue/brown-eyed facial distinctions are Mongoloid-by-degree, and, two, that Mongoliform features are either inherently or presently culturally less 'trustworthy'. Also note that the infantilism mentioned in the paper is, if anything, a feature of East Asians proper and not North Eurasians as such, suggesting that the metrics discussed aren't the product of the suggested admixture.

Another point, a successor analysis method is not always more accurate than a precursor one.

Of course not, but that's the issue. One can't pick and choose which findings to accept and which to reject. The follow-up findings were supported by two separate methods, which the authors deemed more accurate. Sardinians are substantially North Eurasian too, so the original findings only explored excess of said admixture (and possibly inaccurately, since Basques are now shown not to have much if any excess of the admixture).

This is more parsimonious: West Eurasians (without quantifiable recent admixture) cluster too closely together to have significantly different heritage. Even if the signal of North Eurasian admixture were so old as to have disappeared, the genetic difference would still be interpreted as noise, and would set the admixed apart from the non-admixed. All data now support the fact that West Eurasians have comparable levels of North Asian admixture, although I agree that within Europe there is a gentle south-north cline. Lipson et al. also give credence now to such ADMIXTURE/STRUCTURE findings as this:

http://tinyurl.com/athdjvs

It's a pity that no non-European Caucasoids were sampled in the same study.

I could make the same criticism against you that you make against me, but in discussions I direct all my attention to arguments themselves, and I abstain from pointing to motives behind people expressing opposing arguments as much as I can, as that usually does harm to discussions.

I've made no effort in the past to disguise the fact that I like and respect you. No offence was intended, but I feel that unaddressed bias, when dogmatic, also hurts discussion. You're free to address any perceived bias that you feel I display. It's actually healthy: it encourages people to support what they say in future.

Since you also share similar perceptions of me, then, as long as no aggression is involved and no grudges are held, there's no problem in hanging out to dry our suspicions so that we can address them and both feel that in the future we're discussing purely the science and not feel we're each talking to a brick wall.

hamarfox said...

Inflexibility*

I always proofread in my head after I've sent :P

Creative said...

Honestly, I also noticed that many central Europeans are snub nosed due to a low nose bridge, compared to the more clean cut and higher Mediterranean type nose.
Like with Castro and the peasant looking Chruschtschow.

I personally find blue eyed theologians unfitting, "they" remind me of children or to be honest women.

Onur said...

Gregory,

Look carefully at the facial composites of the brown-eyed and blue-eyed males analyzed in this and the 2010 studies:

http://4.bp.blogspot.com/_Ish7688voT0/TBvQ8x9fJmI/AAAAAAAACeg/hTmvLUgaZeo/s1600/bluebrownczech.jpg

Do you really think that the blue-eyed composite is more distinctively Caucasoid and less Mongoloid-admixed than the brown-eyed composite?

Onur said...

Well, not exactly. I've been in numerous discussions with you about this, and my above conclusion is based on the inflexability of your narrative on the issue. Regardless of the progress made in previous debates, you re-enter each topic as though no counterpoints had ever been made. For example, you don't even state that this element may be Mongoloid, but state each time that it is.

I am careful to emphasize the basis of my claims. So I very often use sentences that contain the phrase "according to the results of" and the like. Sorry if I ever sounded inflexible to you.

There are multiple connections to be made: First, that the blue/brown-eyed facial distinctions are Mongoloid-by-degree, and, two, that Mongoliform features are either inherently or presently culturally less 'trustworthy'. Also note that the infantilism mentioned in the paper is, if anything, a feature of East Asians proper and not North Eurasians as such, suggesting that the metrics discussed aren't the product of the suggested admixture.

Firstly, my arguments have nothing to do with the trustworthiness issue. Slight Mongoloid features may be less trustworthy or not among Caucasoids, but that is not the topic of my discussion. Secondly, physical infantilism is a general Mongoloid tendency, with varying degrees among the Mongoloid sub-groups. Finally, the Mongoloid tendency of the blue-eyed composites (whether male or female) of this and the related 2010 papers compared to the brown-eyed composites of the same papers is obvious to me.

Of course not, but that's the issue. One can't pick and choose which findings to accept and which to reject. The follow-up findings were supported by two separate methods, which the authors deemed more accurate. Sardinians are substantially North Eurasian too, so the original findings only explored excess of said admixture (and possibly inaccurately, since Basques are now shown not to have much if any excess of the admixture).

This is more parsimonious: West Eurasians (without quantifiable recent admixture) cluster too closely together to have significantly different heritage. Even if the signal of North Eurasian admixture were so old as to have disappeared, the genetic difference would still be interpreted as noise, and would set the admixed apart from the non-admixed. All data now support the fact that West Eurasians have comparable levels of North Asian admixture, although I agree that within Europe there is a gentle south-north cline.


I am not picking and choosing. I am just pointing to a correlation between the facial feature results of this paper and the ADMIXTOOLS and TreeMix analysis results of Caucasoids. I am noting that correlation as positive points for the reliability of the intra-Caucasoid differences in the degree of Mongoloidness according to ADMIXTOOLS and TreeMix.

Lipson et al. also give credence now to such ADMIXTURE/STRUCTURE findings as this:

http://tinyurl.com/athdjvs


That link does not work.

It's a pity that no non-European Caucasoids were sampled in the same study.

Which study?

Onur said...

I've made no effort in the past to disguise the fact that I like and respect you. No offence was intended, but I feel that unaddressed bias, when dogmatic, also hurts discussion. You're free to address any perceived bias that you feel I display. It's actually healthy: it encourages people to support what they say in future.

Since you also share similar perceptions of me, then, as long as no aggression is involved and no grudges are held, there's no problem in hanging out to dry our suspicions so that we can address them and both feel that in the future we're discussing purely the science and not feel we're each talking to a brick wall.


For me, scientific and intellectual fruitfulness is more important than everything else in a scientific discussion. I am willing to keep some of my thoughts (whether positive, negative or neutral) to myself for this purpose. But, of course, I do not expect everyone else to behave like myself in this issue.

hamarfox said...

Onur,

I am careful to emphasize the basis of my claims. So I very often use sentences that contain the phrase "according to the results of" and the like. Sorry if I ever sounded inflexible to you.

You've clung to the same conclusion on this matter throughout, regardless of the current state of knowledge. This is obstinacy. You originally discounted my Fst/PCA-based arguments (spuriously, I should add) in favour of Patterson et al. My original objections and considerations now seem to be supported by the same lab's latest paper, yet you show no signs of acknowledging this, and instead stick dogmatically to the same tired assertions that not even Patterson would at present support.

Secondly, physical infantilism is a general Mongoloid tendency, with varying degrees among the Mongoloid sub-groups.

The trait isn't pronounced in Amerindians. The connection is minimal between non-recently-admixed Europeans and ancestral East Asians in whom, or in the descendants of whom, infantilism is a distinct trait. Correlation without causation. The Mongoloid connection to Czechs is discussed below, but whether its manifestation is common and consistent enough to explain differences in average blue/brown-eyed features in Czechs is questionable.

Finally, the Mongoloid tendency of the blue-eyed composites (whether male or female) of this and the related 2010 papers compared to the brown-eyed composites of the same papers is obvious to me.

The composites I assume you're referring to are nowhere near detailed enough for that conclusion to be drawn.

I am not picking and choosing. I am just pointing to a correlation between the facial feature results of this paper and the ADMIXTOOLS and TreeMix analysis results of Caucasoids. I am noting that correlation as positive points for the reliability of the intra-Caucasoid differences in the degree of Mongoloidness according to ADMIXTOOLS and TreeMix.

Mongoloid features are present in the Czech Republic, although, of course, this has nothing to do with an ancient North Eurasian ssubstratum, which is significant in populations that entirely or almost entirely lack a semblance of Mongoloid admixture, but it likely does have something to do with the ~2% recent Siberian admixture in Eastern Europeans (which is possibly higher in certain regions and certain individuals, at least in terms of the encoding of certain facial features), that is by and large absent in populations that lack such features.

That link does not work.

http://tinyurl.com/avntanl

For me, scientific and intellectual fruitfulness is more important than everything else in a scientific discussion. I am willing to keep some of my thoughts (whether positive, negative or neutral) to myself for this purpose.

In the realm of pure facts and figures, this is a sound approach. But when we're dealing with other people's (potentially and indeed probably unfounded and arbitrary) conclusions stated authoritatively, and in the absence of any solid consensus, then I believe it's reasonable to question the justifications proffered for said authority, especially when it seems that a scientific debate cannot proceed without such a questioning.

But, of course, I do not expect everyone else to behave like myself in this issue.

It's important, I think, for egos and grudges to be avoided if possible. It can't really be helped, but it damages discourse. Because I'm frequently accused of being abrupt, and, frankly, an asshole, it can be a good thing for me to disarm the impression that I'm hostile to the person behind the arguments and not just the arguments themselves.

Gregory76 said...

Fanty,
My reference to the attributes of the blue-eyed men and brown-eyed men was to those groups as described in the current study, not to what I expected to be true, nor what I still expect to be true, of the average blue-eyed man and average brown-eyed man in Europe or in the Czech Republic.
I sought for an explanation for this, and for the facial composites in the 2010 study by this group, and on further thought came up with the following. As was discussed recently on this blog, blue eyes seem to be of Near Eastern origin, and so Mesolithic peoples would be brown eyed. So the pool of men on which the brown-eyed composite was based would include both Dinaric and Mesolithics, the former providing the long nose and longish face, the latter providing the wide nose, wide jaw and heavy brows. Further, Neo-Danubians are supposed to be partly of Mediterranean ancestry, which leds to be somewhat more gracile than their neighbors. The other main component of their ancetry is supposed to be Ladogan, giving them a broad-face, roundish head, and some features that people may consider incipiently Mongoloid. And they have light coloring, and so many are blue-eyed and hence included the pool from which the other composite photo is made, along with Nordics and others. So this results in the picture having a narrow, pointed chin (a gracile feature), somewhat high cheekbones and a kind of eye that is common in northeast Europeans that somewhat suggests the Mongoloid.
Onur,
I will look at the website you provide the link to in the near future.

szopeno said...

@aspromavro
The explanation is probably quite simple: Slavs tend to view Germans with suspicion. Hence, the less you look like a German, the more trustworthy you are perceived to be.

Not possible. Most northern Slavs have blue or grey eyes.

aspromavro said...

@szopeno, YES, those with Baltic and Finnic influence do have such eyes nowadays, but we are talking about Czechs vs Germans, and ancient Slavs vs ancient Germanic peoples. Also eye color in itself doesn't explain the phenomenon, it just correlates with other features.

Onur said...
This comment has been removed by the author.
Onur said...

Hamar,

You are largely not arguing with me but a misrepresentation of me. All I did in this thread was noting a correlation that is in favor of the intra-Caucasoid Mongoloid admixture differences based on the ADMIXTOOLS and TreeMix analyses. That does not mean that those intra-Caucasoid difference results are necessarily accurate. It just means that after the publication of this Kleisner et al. paper they now have a more likelihood to be accurate.

As for the neoteny (=physical infantilism) issue, we do not know the degree of neoteny in the hypothetical ancient North Eurasian population. They may have been more similar in this regard to modern-day Siberians, who have a high degree of neoteny, than to modern-day Amerindians, who are less neotenous than modern-day Siberians and East Asians. It should also be noted that Amerindians in general are far more neotenous than Caucasoids in general. So there is no correlation without causation issue.

szopeno said...

@aspromarvo
So, you are arguing that VAST majority of modern Slavs are Germans and Finnish? As I say, majority of northern Slavs (i.e. Poles, Russians, Slovaks, Czechs) have blue and gray eyes. Northern Slavs form majority of Slavs (There is more Poles alone that all southern Slavs combined). In Poland blue and grey eyes are in about 60=70% of population. What's more, the "typical slavic beauty" in Poland means blonde with blue eyes and there is no sayings and prejudices against blue eyes.

Now, how it;s likely that ancient Slavs have in majority brown eyes, if a) ancient people living near Slavic ancestral lands, from ancient graves, are found to probably have blue eyes (scythians e.g.) b) modern Slavic populations near ancestral lands have predominantly blue or grey eyes c) there is as much light eye perecentage amongst modern Slavs than amongst Germans? (Poland: 68% blue, Russia and Czechs: 65%, Belarus: 74%, contra Germany 70%, though more northern Germanic nationas as Norway and Sweden have even more: 88%. Blue eyes alone: Germany 53%, Poland 50%, Czecha and Russia 48%).

It seems to me that ancient Slavs were most likely to be blue-eyed in their majority. The percentages are too large to make it possibly that it's due to ugro-finnic and German admixture, especially as in DNA testing it seems that northern Slavs (+slovenians and part of Croats, - part of Russians) form quite a distinct cluster, different from Germanics and Ugro-Finns.

Unless you can provide me with a proposal of a process which would leave majority of Slavs blue-eyed from solely Ugro-finnic and Germanic admixture, without leaving traces of significant admixture within their DNA)

SimonW said...

I remember reading about a similar study on this blog, some time ago, also on Czech people, that concluded that brown eyed people are perceived as more dominant looking than blue eyed ones. In that study there was also a strong association of the different eye colours with different facial shapes and features. The morphs of the blue eyed Czechs looked more "Baltid" or "Osteuropid", whereas the brown eyed Czech morph looked more "Atlantid" or "Mediterranid". The former type probably comes mostly from the Slavs, the latter type is to a large degree pre-Slavic. The Czechs being a Slavic people, in theory they should rate the Slavic type as more trustworthy. But I think the modern Czechs, having being wholly Slavicised for centuries, no longer perceive the Baltid facial type as more Slavic than other types. I think linkage disequilibrum and a slight tendency of Atlantid types to more trustworthy behaviour might be the explanation.