Blonde children exhibit more fear response? A new paper reports:
...Hair pigmentation was found to be significantly associated with behavioral inhibition in the sense that blond children exhibited higher fear scores. As in American samples, blue-eyed children had a higher fear score than did other children, but this difference was not statistically significant.
Jerome Kagan has reported these sort of findings before. Coloration is a funny trait, for example, there is now evidence that Europeans are highly constrained on one locus which affects complexion, while being high polymorphic on another (MC1R, on which East Asians seem to show strong recent positive selection). The finding that blue eyed or blonde youth tend to be more withdrawn or shy probably isn't that surprising, and it makes one wonder how such a bias might have shaped the higher order "characters" of cultures in the north of Europe. If I had to guess I would point the finger at pleiotropy in this case.
Here is the older research by Kagan:
Two independent investigations of the association between the temperamental dimensions of inhibition and lack of inhibition to the unfamiliar, on the one hand, and the degree of pigmentation of the iris, on the other, revealed a statistically significant relation in Caucasian children between behavioral inhibition to the unfamiliar and blue irises and uninhibited behavior and brown irises....
Please note that MC1R is uncorrelated with eye color, though it does have a relationship to skin tone.
Update: A few clarifications and caveats. In terms of this not being surprising, I'm making the rather weak observation that the blondest nations in Europe stereotypically are characterized by societal introversion. This is not to say that I am arguing for clear and deep national characters, the ancient Romans were perceived by contemporaries (at least during the republican era) to be stoic in persona, while modern Italians are rather not typified by this stereotype. German efficiency would have been surprising news to ancient peoples. Nevertheless, I suspect there are some basal predispositions at work that might vary between populations.This paper on variation on the DRD4 receptor across populations is in the direction I suspect more data is going to be unearthed.
Second, in terms of "higher order" characters, this is what I am getting at. Imagine two populations, for simplicity assume they are arbitrarily large. Assume an extroversion metric, 0 to 10, and assume that there is an underlying genetic component to this. All things being equal, assume that population A consists of 60% of individuals with extroversion level 8, and 40% extroversion level 2. Assumine that in population B the numbers are reversed, so 60% have extroversion level 2 and 40% have extroversion level 8.
So, expecation of A = 8*.6 + 2*.4 = 5.6
Expectation of B = 8*.4 + 2*.6 = 4.4
But, humans do not develop independently in a vacuum, they interact with other individuals. If you assume random interactions, then in population A the individuals who are less extroverted will more likely be interacting with more extroverted individuals and those in population B who are more extroverted will interact more often with less extroverted individuals. In their book Not By Genes Alone, the anthropologists Peter Richerson and Robert Boyd review extensive psychological literature which suggests that humans seem to have a "do what most people do" cognitive bias, so the bias of who you interact with might have powerful developmental effects.
Granted, the model above is highly simplified (one assumes that interactions are not random within a population), nevertheless, the basic gist is that in populations A & B would be deviated away from the expected mean toward the mode because of social factors. Ultimately the same logic applies to purely culturally heritable traits as well, perhaps explaining the "flips" in state from the ancient Romans to modern Italians (I find arguments that exogenous admixture caused these changes unpersuasive, though I am open to the possibility of endogenous change in gene frequencies).
Update II: Here is the table you want:
Here is part of the discussion:
..a common precursor for the melanocyte-stimulating hormone and beta-endorphins, with the latter mediating a higher threshold of physiological arousal. Propiomelanocortin is co-produced with corticotropin-releasing hormone (CRH) in human hair skin (Kono et al., 2001) which might be of potential relevance given reports that inhibited children tend to show higher cortisol levels (Kagan et al., 1988, 1987; Fox et al., 2005). The finding of a elevated baseline cortisol in inhibited children led to the assumption higher cortisol levels may induce changes in the amygdala, thereby exacerbating or even precipitating inhibited behavior (Schmidt et al., 1997). This potential biological mechanism might contribute to an explanatory model for the association of hair pigmentation and fearfulness, as amelanocyctic hair builds seem to produce and significantly higher levels of CRH (Ito et al., 2004) and this production has been described as substantial enough to manifest itself in different cortisol serum levels (Ito et al., 2005)....
References:
Moehler E, Kagan J, Brunner R, Wiebel A, Kaufmann C, Resch F, Association of behavioral inhibition with hair pigmentation in a European sample, Biol Psychol. 2006 Jan 13.
Rosenberg A, Kagan J, Iris pigmentation and behavioral inhibition, 1987 Jul;20(4):377-92.
I wonder how much of this effect is purely genetic and how much is cultural. In Germany, there is a relatively large and relatively recent (since the 60's-70's) immigration from Turkey and other mediterranian countries.
There's likely to still be a strong correlation between eye and hair colour and ethnicity. I have only read the abstract, but I don't see that these factors were discussed, much less investigated.
Purely anecdotal evidence - My blond hair, blue eyed son, and two of his blond hair blue eyed cousins had fear issues - we called them safty boys. The blond hair, brown eyed cousins and the brown hair brown eyed siblings do not seem overly cautious.
why do you say this is "probably not surprising"?
I'm not shocked, but a little surprised nonetheless...
Very interesting stuff.
In Germany, there is a relatively large and relatively recent (since the 60's-70's) immigration from Turkey and other mediterranian countries.
i assumed when they same 'german' they would correct for ethnicity. also, some of the earlier work, from what i recall, was done on sibships. the blonde brothers in one study were found to be apprehensive by their mothers. obviously there might be confounding factors.
I'm not shocked, but a little surprised nonetheless...
many of my close associates are of nordic heritage...and their personality fits in with a tendency toward shyness. also, i know of the stereotypes of how finns and swedes behave, and gregariousness sans alcohol seems thin on the ground. one hypothesis, adaptionist, is that this personality is a reflection of low density life and late acquisition of agriculture (there as a 5,000 year latency between the near east and the nordic countries). but, i suspect that pleiotropy is more plausible.
What is the magnitude of the difference? The abstract says behavioral inhibition is "slightly more frequent" among blue-eyed people, and "significantly associated" with hair pigment, but that doesn't really tell us much, quantitatively.
i'm trying to get a hold of the paper! my uni access doesn't cover that journal.
I read in Stanley Corren's "The Left-hander syndrome" that left-handers tend to be more blond and more blue-eyed than the right-handers.
Also, blond folks tend to have lighter skin, and skin is 0.92 correlated with IQ.
I remind you that the B.I.S. might be linked to higher IQ: after all, highly intelligent folks tend to see through the implications, to foresee, to examine all sides of the issue, i.e. they might be more cautious, fearfull, because they see the dangers lurking behind appearances.
I bet that a study comparing the IQ of people high on B.i.S. with the IQ of people high on B.A.S. will show the former group to score higher.
Also remember the BIS people tend to be more introverted; but at very high ability levels, the % of introversion also goes up.
So there are some links to explore here:
BIS - IQ - blondness - blue-eyedness - introversion - lighter skin - (and for males gender-atypical behavior/homosexuality).
Oscar Wilde syndrome?
Also, blond folks tend to have lighter skin, and skin is 0.92 correlated with IQ.
correlations of correlations can be deceptive. i believe jensen's examination of intrafamilial IQ and coloration didn'tt show a trend toward dark siblings exhibiting lower IQ. in other words, the correlation is due to another causal factor. there was a reason i said the trend was weak, you need to be cautious when stringing together a sequence of suggestive correlations, reading too much into such things without reflecting on the glaring weaknesses in the argument is suggestive of low IQ :) (eg., males are 5-10% darker within a given population but don't seem to exhibit lower mean IQ, east asians score somewhat higher on culture free tests than lighter skinned europeans).
Where I grew up, only gypsies could have brown eyes. Up to until I moved to the city as a young adult, I had no brown eyed acquaintances - I had seen such people, but not more than that. An obvious (but boringly cultural) hypothesis would be that in such environments brown eyed people would *have* to learn to be less inhibited to compensate for social exclusion as kids (which was very real, kids are brutal to anyone who looks different; I remember we talked about this at school, wondering why some people look different, and the explanations were of course usually something adults would've considered extremely nastily racist - brown eyed people are freak mutants whose touch can infect others with disgusting gypsy diseases or something like that). And of course, standing out can be a positive thing for social success, too, especially when you get to the dating age.
Of course, if this idea were true, the roles would be switched in studies from regions where the blue-eyed people are a minority.
After watching a lot of blonds risk their necks in the Winter Olympics, I would surmise that the "fear" that Kagan is referring to is more like fear of offending other people in social situations than physical fear.
As the point about the death-defying Nordic Olympic sports notes, a good question is: Fear of *what*?
When I was growing up, a Black friend of mine once said, "White boys are crazy. Who else would jump out of airplanes or go bungee jumping. You'd never see a Brother doing that." Years later, this same guy got himself in jail.
My informal observation has been, since childhood, that many blonde-blue people are somehow cognitively "indirect" in a way that's hard to describe. They seem "disconnected" from their own emotions and impulses, and to have difficulty understanding the emotions of others - as if logic interjects before they get a direct "info feed" of their own inner experience.
I also notice that blond-blue people tend more to see other races and ethnicities as quite alien to a higher degree than average. Compare Anglo-Saxon racial policy in North America to Latin Spanish and French policy in the same region: the Anglos never wanted to assimilate, but the slightly darker French and Spanish were much more open to the idea. On the other hand, Northern Europeans seem overrepresented among the world's great daredevil explorers.
Afrocentric pseudoscience has speculated quite a bit about neuromelanin, the hidden correlary of visible pigmentation. At any rate, the effect found in this study is subtle. But perhaps in a society with enough blondes, an overall effect could be seen.
i agree with Steve, i think it is must be societal not physical. Hasn't there been some work on the heritability of shyness?
perhaps it is correlated.
After watching a lot of blonds risk their necks in the Winter Olympics, I would surmise that the "fear" that Kagan is referring to is more like fear of offending other people in social situations than physical fear.
No, the experiments really did involve fear fear. Unfamiliar people, but also scary puppet shows and strange objects. But it is interesting that Xtreme sports are popular in Northern Europe. Maybe culture demands more credit here. Then again not all the research seems to fit together in an intuitive or elegant way - Northern Europe seems to be high in extraversion and low in conscientiousness in the Toward a Geography of Personality Traits paper, free to download at the Journal of Cross-Cultural Personality.
I also notice that blond-blue people tend more to see other races and ethnicities as quite alien to a higher degree than average
Another contradiction, by the way, given other accounts of low Northern European ethnocentrism. Both seem to be getting at something. We either have poor models or poor data to look at this stuff.
If I had to guess I would point the finger at pleiotropy in this case.
See also blue eyes and deafness in cats.
But Jason, how are puppets and strange objects related to physical fear? I mean more like fearing a slalom run or mogul field. ;)
I don't get your question. How is a scary puppet not related to physical fear? A better question is how are puppets and strange objects just reflecting social anxiety?
I guess if i were designing the experiment, i would have had the test subjects climb a ladder or a rock wall or jump down from some height, or jump across something--or go really fast-- something that involved physical motion.
maybe we are talking about two different things.
Additional points. First of all fearful temperament is also something found in Amerindian and East Asian children in a number of experiments, as I pointed out in an old post. Fearful children stay closer to their mothers, and that the populations that exhibit this appear to be cold adapted (or closely related) might suggest that staying close to mom is important for survival in young children the further north you go. Blondness (and blue eyes) then would more likely be a byproduct of the temperamental selection instead of vice versa (sexual selection). Other populations found different pathways to the same phenotype. To Steve's point, if this temperament is only important for the survival of young children, I wonder if it's possible that Northern Europeans actually grow out of it? All of the research seems to be on children, I wonder if we would find the same relationship for adults? Perhaps related is that blondness changes with age; my hair is basically black right now, but my first several years or so I was light blonde. Same I think for my biological father. Does that mean I should exhibit the fearful temperament or the "brunette one"? Or does it signify my temperament shifted with development? Would I have been fearful at 2 but "normal" at 4?
NuSapiens, one factor could be that there's not merely a slight colour difference between southern and northern Europe, but in the south variation in skin colour is greater. I'm not sure how true that was of imperial Britain, though, but compared to really northern Europe, there's *much* more variation in looks within eg. the France you mentioned (of course, it's a much bigger... well, not a much bigger country, but with a much larger population). They could be more accepting of diversity of looks simply because they're more used to it.
Jason, it's not just hair, northern Europeans' skin also gets darker by age. Notable skin and hair colour darkening is much more common in men - and a gender disparity that also corresponds to the aesthetic ideals of the sexes suggests sexual selection, doesn't it? (Well, of course then there's also the question of why the sexes are viewed that way.)
And it's not true that ethnocentrism would be low in northern Europe. It's consciously muted and shunned in politics (especially in Germanic countries, after that bit of nastiness in the previous century), but that doesn't make it go away. It's well-hidden from outside view, so to learn about it you generally have to speak directly to a native and administer large quantities of vodka to the test subject. Polls will do, too, *if* you ask the right question (ie. ask people here if they're racist and everyone will say "of course not!", ask them "would you ever consider moving next door to a dark-skinned person?" and a third will say "absolutely not, what a ridiculous question!"). (There are some very large differences between countries in the content of ethnocentrism and just who the disliked/hated groups are, though.)
Compare Anglo-Saxon racial policy in North America to Latin Spanish and French policy in the same region: the Anglos never wanted to assimilate, but the slightly darker French and Spanish were much more open to the idea.
well, one plausible explanation of the difference though is that the british colonies were more explicitly 'settler' enterprises. the ration of whites:non-whites was far higher than in canada (where there were fewer french) and in the south (where a large number of amerindians remained after the die offs). the culture of argentina and chile shows what happens when the iberian component is predominant, more european oriented societies.
How many blond politicians, serial killers, gangsters, leading Nazis etc compared to general population?
After watching a lot of blonds risk their necks in the Winter Olympics...
If blondness is related to adaptations for survival in cold, blonds may just be more comfortable with winter sports: the temperature and light-levels are right, so they have psychic energy left over for risking their necks.
I suspect the term "behavior inhibition" (like "risk aversion") is too general. The real question is more deeply ingrained in perception: which stimuli do people perceive as "dangerous"?
As someone else mentioned, this study did exclude based on the (presumably mother's) ability to speak and read German. However, there is a significant Turkish population in many German cities, so cultural factors are another possible factor. Nevertheless, my anecdotal observations include intrafamilial differences.
One of the experiments here was a tasting experiment - and something I've noticed is that blond-blue people often have an aversion to unfamiliar or spicy foods. Northern European cultures have historically had less access to spices, but perhaps demand was also a factor - it's difficult to separate cause/effect here, but there does seem to be a correlation.
I don't know if this is relevant, but melanin is related to the phenethylamines (it is produced from tyrosine, which is closely related to dopamine and noradreneline). Phenethylamines include dopamine and noradreneline, as well as cocaine, amphetamines, and methylphenidate (Ritalin). So perhaps there is something inhibiting the availability of tyrosine to be converted into both melanin and dopamine, thus linking light coloring and a fearful demeanor. I believe those with lighter coloring are also more likely to become addicts or alcoholics (I happen to be blond-haired, blue-eyed, anxious, socially inhibited, and a raging addict-alcoholic). That blondes would be more likely to become addicts or alcoholics is hardly surprising in light of the cited study, because most people do not enjoy being fearful, anxious, depressed, etc and will often do whatever it takes to get out of such feelings, including abusing drugs and alcohol.
Also, blond folks tend to have lighter skin, and skin is 0.92 correlated with IQ.
There is a correlation of -0.92 between national IQ, as measured by Lynn and Vanhanen in IQ and the Wealth of Nations, and national skin color. However this refers to NATIONAL AVERAGE skin color and NATIONAL AVERAGE IQ. The individual correlation is considerably lower.
thank you ScienceBlogs enjoyed reading the article.