Genes and Race

What roles do our genes determine in our racial identity?
Is merely a different form of nature versus nurture ?
Do people with the gene for darker skin, adopt different cultures/racial customs/tendencies ?
Does a second generation migrant have the same racial characteristics as someone of the same age back home ? Is it even "home" to them?

Or is it our environment ?

 

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Despite what some may claim or hope to be true, the concept of race is a genetic reality. An Asian couple will give birth to an Asian child, and to refuse to acknowledge this is silly. However, the above statement is in need of some serious qualification.

One qualification is that while the presence of genetic differences between racial groups is indisputable, the exact boundaries that define race -- whether genetic or physical -- are fuzzy at best. There is no general agreement on how many races the world is said to have. The differences represent more of a gradient than a hard demarcation. While sometimes the physical differences between members of a separate race are clear, many other times making such a distinction is an entirely arbitrary affair.

Another qualification is that while these genetic differences exist, they are meager. Race accounts for only about 10-15 percent of the genetic variation between humans. When you consider that all humans share about 99.9% of their DNA, this means that race is represented by about 0.0125% of the human genome. It also means that the genetic differences between the "average" members of two separate races is, on average, far less than the genetic differences between two randomly selected individuals from a single race. There is far more variation within racial groups than there is between racial groups.

A final qualification is that racially-based differences in behaviors and/or behavioral traits -- if, indeed, they have much of an existence at all -- are completely obliterated by culture and environment. Slews of studies have failed to statistically implicate race and rule out culture and environment in accounting for individual differences in behavior. Importantly, there are certain group differences that happen to correspond to racial groups. See this recent thread for a discussion of that. However, there is simply no good evidence that these differences can be chalked up to race -- they appear to be byproducts of culture and environment.

Does this mean that race is a negligible concept? No. Like I said at the beginning, the concept of race is a genetic reality, and it does have some important implications in the medical domain (with certain races having very different incidences of certain genetic diseases). But what it does mean is that discrimination based on race alone simply doesn't make sense. If one adopts a child from a stone-age African culture and raises him in southern California, he will grow up with no discernible behavioral differences from his American peers. It is culture that is the great driver of group differences -- not race.

 

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The genetic "races" do not correspond to the social ones, however.

There is no "concept" of genetic race in which all the white people are one race, all the yellow people are one race, all the red people are one race, all the brown people are one race, and all the black people are one race.

And that is one of the major difficulties facing attempts to correlate things like disease with genetic race, using data classified by social race. The correlation between the genetics and the sociology is difficult to make rigorous.

 

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I think I remember reading some things about a year ago that showed that there were a few slight physiological differences in the brains of each race. I think black brains were slightly smaller than white brains due to having smaller heads, or some such. I'll post it when I find it.

While I doubt that such differences have any significant impact on function, it's not such a foreign idea. People of certain races happen to carry along genes that are more common within their racial group than in others. Example: blacks and their higher than average propensity for sickle cell anemia. The differences are not a function of the race, though, but of the genes that happen to be more common in their group.

...Which I suppose holds true for genes that *are* defining attributes of a racial group.

 

All such studies begin by simply accepting the sociological classifications of "race". So they are bullshit, genetically, even before they have begun to fail to allow for economic and dietary and cultural and other such influences.

Vulnerability to sickle cell anemia is characteristic of only a certain proportion of "blacks" - most are in some completely different genetic group, a different "race" if you will.

There are no such genes, for sociological races. The genes producing, as their normal somatic expression, melanistic skin, for example, are different in different sociological "black" people.

Here is a map of sickle cell genes: http://en.wikipedia.org/wiki/File:Sickle_cell_distribution.jpg

Note the lack of correspondence to a map of any sociological race.

 

Do you listen at all? I just said that the propensity is not a function of race. It's just a genetic attribute that is propogated along racial lines. EXAMPLE: most people who have sickle cell anemia in America are black. What began as a resistance to disease in Africa became something that continues to affect mainly Africans and people of African descent due to breeding habits.

Culture affecting brain size.

Wow.

 

The propensity is not propagated along sociological racial lines, however - it is not propagated along the lines of those American blacks who trace their genetics to other ancestral genetic groups.

If, as a doctor, you commonly suspect (and routinely test for) sickle cell among the children of immigrants from Micronesia or Australia, because they are black, and overlook the symptoms in children of immigrants from northern India or Turkey, because they are not black, you will be making mistakes.

The sociological races do not correspond with genetic groups.

? How about body size - do you think culture has no effect on average height?

 

Yes, question: if two blondes have a child, which is overwhelmingly likely to be blond, does that mean blond is a race?

 

80 years ago Germans, French, Polish, English, Italians, Spanish were all different "races". I don't believe in "race" per say. Are Japanese and Chinese a different race? They think so. I don't.

The only thing I wonder about is if certain groups of people that have been isolated and selected against may have on average in a given population propensity towards this or that, like creativity, or better problem solving ability, or following leaders, or believing in Gods. How much of that is genetic and how much is environment? When the two meet then what?

 

That is very true. And it sort of goes back to the earlier point about the boundaries that define race being fuzzy and more or less arbitrary. However, it's also true that while the correspondence between the genetics and the social constructs is highly imperfect, there is still a certain degree of correlation. I'll expand on the implications of this below.

It is indeed difficult to make the correlation completely rigorous -- however, that doesn't mean the social constructs aren't useful in medical situations. For example, let's consider the situation in the United States, which has a very diverse ethnic composition. Based on 2003 statistics (1,2), 1 in 12 African Americans has at least one of the sickle cell allele (being a recessive trait, it takes 2 alleles to develop the full disease). However, in the general US population the prevalence of the allele is 1 in 147. This means that, without any other knowledge, we know that a patient is over 12 times more likely than the average patient to have the sickle cell allele simply by virtue of being African American. I couldn't find precise statistics on the full blown disease, but presumably the relative proportions are about the same -- the image below suggests that this is indeed the case, although I couldn't locate the statistical source.

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This is important for medical diagnoses not because it determines who gets tested; a doctor who neglects to test certain groups in the way that you described will indeed make many errors. Rather, it affects medical diagnoses because knowing the base prevalence rates in the population to which a member belongs is very important for interpreting the results of medical tests. This is because medical tests are not perfectly accurate -- they sometimes give false positives and false negatives, and these accuracy rates can be and are regularly quantified.

Minding the relevant base rate in interpreting a medical test is a very unintuitive concept, so to wrap our heads around it, consider the following hypothetical problem.

If a test to detect a disease whose prevalence is 1/1000 has a false-positive rate of 5 percent, what is the chance that a person found to have a positive result actually has the disease, assuming that you know nothing about the person’s symptoms or signs?

The most common answer -- given by the majority of respondents when this problem was first presented by researchers Cascells, Schoenberger and Graboys in 1978 -- is 95%. The correct answer, pursuant to Bayes' Rule, is 1.96%. This is most easily explained by imagining that there are 1000 people, of whom 51 will test positive (50 false positives and one true positive) and of whom only one actually has the disease (prevalence is 1/1000). 1 out of 51 equals a probability of 1.96%.

There are two reasons why this is important in the current context. One is that the correct probability of having the disease is sensitive to the base prevalence rate one uses in the calculation. In the case of sickle cell, the calculation for an African American patient would use a much higher base rate, and the output would be a much higher probability of disease. But wait -- why wouldn't you just begin treatment on anyone who receives a positive test result, just in case? This is the other reason why base rates are important. Treating a disease that one doesn't actually have can be costly, dangerous, or both. It is not a decision to be made lightly, and treatment should be pursued only if the probability of disease exceeds a certain threshold which is to be determined by the patient and/or doctor.

Using the base rates ascribed to various socially-constructed race groups is entirely prudent. It is, in fact, the doctors who ignore race-based differences in disease prevalence who will make the most errors.

 

I would have to say that race does play a role in it. Asians are conservative and restrained in their behavior, in general industrious and family oriented, and display patience and scholarliness. This behavioral pattern holds fast even when they migrate to other countries such as America or Europe, their culture adapts to the new environment but stays true to its basic nature as just described. Asian culture includes great works of art, statues, palaces, music, philosophy, religion, that in some cases rivals that of European culture. We see this in China, Japan, Veitnam, Korea. I think you could transplant Asians to geographically anywhere on the globe and you would get the same results, because its in their genes. When you consider all of the different peoples across the globe, I think what you see culturally is an expression of the genes of the different races. No race is better than any other, but they are different.

 

Japanese and Koreans are somewhat similar but I think they are very different compared with Chinese.

 

Hello, fellow mongrel..

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I'm assuming you're talking about the Aboriginal Australians, because I doubt that 100 years is enough time for convicts to produce/evolve into their own race/version of "caucasian".

 

Fraggle Rocker,

What I sometimes wonder about is how much genes play a role in democracy and how much is culture. I often think about the ME. Sure many people, like SAM, will say time and again it's all the USA fault. But, when you think about it, people in the ME have been exposed to the ideas of democracy since Alexander of Macedonia came by. And many ancient leaders attempted to implement these ideas many many times - it always failed.

Considering how many different cultures have existed in 2000 years I wonder if it may be genetic? Too much follow the alpha-male genes in the population washing out the few genes that want democracy.

Did you know that male orangutans stunt sexual development if an alpha male is around. They only grow to the size of a female (half that of a male). As soon as the alpha male is gone all males will quickly mature and attack one another. All of this is genetic of course.

On another note, I wonder what the pressures of living in Europe selected for? Ingenuity? Creativity? War-like? (i mean look at the size of Dutch)

 

Those four genotypes do not correspond to the white, yellow, red, brown, and black "races" I specified.

Two of them and parts of another (e.g. the Pacific Islanders) are in one "race" - black. Part of one is in the "reds", another part is in the "yellows". There are "browns" in three of the four. There are "whites" in at least two of the four. And so forth.

The simple way to say it is that there is no genetic basis for the sociological races.

The Dutch were some of the smallest people around for centuries prior to WWII - they are having a interesting architectural time nowdays, as the latest generation find itself unable to walk upright through the doors and stand up straight in the parlors of their grandparents' houses.

Human height does not appear to vary much, if at all, genetically, barring a couple of outliers (the African pigmies, best known). John Komlos and his fellow researchers, AFAIK the only people who have bothered to actually collect serious data on the subject, have so far found the greatest likely genetic difference in height between major demographic groups of humans to be no more than 5/8 of an inch - and just as likely less.

Consider any conclusions about genetic propensities for "democracy" in that light - remembering the old Greeks and the Roman Senate before Caesar, both of Middle Eastern genetic heritage (if there is any such thing).

 

I doubt dictatorship is a gene, or that concepts of governance are genetic. It's a very tenuous link there.

 

Of course there is a genetic basis for racial classification, what an absurd thing to say. Why do you want to deny that identifiable races exist, its like you think that the concept of race is a bad thing. People are equal, regardless of their race, but it is undeniable that races do exist. Even if the only difference between blacks and whites were skin color, blacks and whites could be classified on that basis alone, without any positive or negative connotations.

As far as I know, blacks, whites, and asians possess exactly the same genes. The differences between the races that we observe are the result of differences in the DNA molecule sequences of those genes. There is a gene, or genes, that code for the color of ones skin, blacks having the gene variation for black skin, whites for white skin. When a black person and a white person mate, you get an intermediate skin tone and we say that person is of mixed race, but racial classification is still possible. The races differ on more than skin color however, so that even a person of African descent who inherits the gene for albinism can still be properly classified by their hair texture, shape of thier face, and racially distinguishable characteristics of other facial features.

Please don't try to insult my intelligence by telling me that there is no such thing as race.

 

You and iceaura are saying the same thing. He said that there is no genetic basis for sociological races ("asian", "black", "white" -- these are social constructs that contain many races within them).

 

Saying that black, white, and asian are social constructs is like saying that male and female are social constructs, which is patently absurd. He is saying that racial categories are made up out of whole cloth, a figment of man's imagination. This is what the term social construct means. To expect someone to believe that defies intelligent thought.