4 ms·

There is so much discussion today about the natural or genetic differences between groups of people, couched as science, but it's pretty bad science. Humans are

There is so much discussion today about the natural or genetic differences between groups of people, couched as science, but it's pretty bad science. Humans are genetically identical to what they were 1000 years ago, even 10,000 years ago, yet we've moved from wearing loin cloths to putting people on the moon. I'm sure genetic differences exist, but any nature is ridiculously out-weighed nurture and society, on the scale of 1000 to 1. Folks just look for nature based answers because it gives them an excuse to not examine their own place in society.

zaarn 8y ago
We're not at all genetically identical to 10'000 years ago, lactose-tolerance (not intolerance) has developed in that timeframe and even in modern populations, some lack the genetics to produce lactase. Another example is ADH1B, which is also not present in all populations and a fairly recent development. There is fairly well established science outside genetics that establishes that the average distribution of brains in bimodal over female and male sex. An MRI scan can predict your sex better than random choice. There is plenty of people who outright dismiss such results as "bad science" because they interpret the results wrong and draw bad conclusions (mostly that either female or male brains are worse somehow for everyone). These are averages. Lots of people being measured. Nobody who properly reads the studies for this should conclude that there is a typical female or male brain. There are some features that are more likely to be present in either, some less like to be present or differently expressed. On average. It's perfectly possible for a female to have a brain that would have only features that are more typical for male brains and a male may have features more typical for females while they behave perfectly normal compared to a control. There are plenty of features that differ between males and females on average and there is no problem when one has a feature being expressed in a way more typical of the other sex (just think of hip size, hair, height, voice, etc).
- speedplane 8y ago
  > There is fairly well established science outside genetics that establishes that the average distribution of brains in bimodal over female and male sex. An MRI scan can predict your sex better than random choice. I'm not saying that there aren't differences, I'm just saying they are practically negligible when they are compared to social differences. I don't doubt an MRI can predict sex relatively well, but a far more accurate prediction can be based off of what type of underwear you wear and whether you carry a purse or a wallet. The social constructions and stratifications we have made for ourselves are far more powerful than differences in our own genetic code. It's largely this ability to modify ourselves through society that differentiates us from other animals.
  - darawk 8y ago
    > I'm not saying that there aren't differences, I'm just saying they are practically negligible when they are compared to social differences. I don't doubt an MRI can predict sex relatively well, but a far more accurate prediction can be based off of what type of underwear you wear and whether you carry a purse or a wallet. Do you base that conclusion on a careful reading of the empirical evidence? > The social constructions and stratifications we have made for ourselves are far more powerful than differences in our own genetic code. It's largely this ability to modify ourselves through society that differentiates us from other animals. Tell that to someone with Down syndrome. Genetics are quite powerful.
    - speedplane 8y ago
      > Do you base that conclusion on a careful reading of the empirical evidence? Since the industrial revolution humanity has changed so quickly to become practically unrecognizable to those who came before it. A "careful reading" of Darwin, Dawkins, or any credible geneticist explains that is not even a blip in the genetic timescale. How could you explain that change with genetics alone?
      - darawk 8y ago
        Nobody is talking about differences from humans now to pre-industrial revolution. We're talking about differences between the sexes - an evolutionary pairing older then the species itself.
- belorn 8y ago
  An interesting similar study was one where they did the same scans on transsexuals. Those found that the MRI predicted the gender that the person identified with rather than the one they were born with.
dandare 8y ago
The nature vs nurture debate is not new. Do you have any evidence for your "ridiculously outweighed" claim? From Wikipedia: "Early studies of intelligence, which mostly examined young children, found that heritability measured 40–50%. Subsequent developmental genetic analyses found that variance attributable to additive environmental effects is less apparent in older individuals,[45][46][47] with estimated heritability of IQ increasing in adulthood."
sadris 8y ago
Everything you said was incorrect. There isn't a single trait ever examined in which the impact of shared environment is larger than the genetic impact. In other words, the heritability of every trait ever examined is vastly larger than the effect of the shared environment (nurture). It's literally the second law of behavioral genetics: The effect of being raised in the same family is smaller than the effect of the genes. And about evolution, also wrong. We have evolved 100x faster in the past 5000 years than in the Pleistocene. https://en.wikipedia.org/wiki/The_10,000_Year_Explosion https://en.wikipedia.org/wiki/The_10,000_Year_Explosion People like to believe in falsities like yours because they don't want to admit than ability is mostly innate and there's nothing we can do about it.
- belorn 8y ago
  Most people misunderstand heritability, but there is an excellent video I can recommend by professor Robert Sapolsky: https://youtu.be/RG5fN6KrDJE?t=2427 https://youtu.be/RG5fN6KrDJE?t=2427 A common finding is that if you want to explain data around a trait and you can only know the environment or the gene, the environment is usually the better choice. The interaction between genes and traits is very counter intuitive for most people. As an example from the lecture, if we asked people how heritabile the number of fingers a person has we would expect the answer would be 100% since it is very rare for a person to be born with 4 fingers. But if we asked if genes or environment is the best method to explain why some people have 4 fingers, genes are a very proof explanation since finger amputation are caused very rarely from genes. The variation of fingers among humans has thus a very low (almost 0%) heritability. Heritability == the observed variation in the data set that can be explained from genes.
  - sadris 8y ago
    Correct. That's why I explicitly said shared environment (the "nurture") and not all environment (which includes non shared environment). When comparing nature vs nurture it's going to be always nature. When comparing total trait variance, the genetically explained variance is on average 50% (averaged across all traits). A fraction of the remaining 50% is non shared environment (randomness) and a minute/neglible amount is shared environment (nurture).

zaarn 8y ago

We're not at all genetically identical to 10'000 years ago, lactose-tolerance (not intolerance) has developed in that timeframe and even in modern populations, some lack the genetics to produce lactase. Another example is ADH1B, which is also not present in all populations and a fairly recent development. There is fairly well established science outside genetics that establishes that the average distribution of brains in bimodal over female and male sex. An MRI scan can predict your sex better than random choice. There is plenty of people who outright dismiss such results as "bad science" because they interpret the results wrong and draw bad conclusions (mostly that either female or male brains are worse somehow for everyone). These are averages. Lots of people being measured. Nobody who properly reads the studies for this should conclude that there is a typical female or male brain. There are some features that are more likely to be present in either, some less like to be present or differently expressed. On average. It's perfectly possible for a female to have a brain that would have only features that are more typical for male brains and a male may have features more typical for females while they behave perfectly normal compared to a control. There are plenty of features that differ between males and females on average and there is no problem when one has a feature being expressed in a way more typical of the other sex (just think of hip size, hair, height, voice, etc).

speedplane 8y ago
> There is fairly well established science outside genetics that establishes that the average distribution of brains in bimodal over female and male sex. An MRI scan can predict your sex better than random choice. I'm not saying that there aren't differences, I'm just saying they are practically negligible when they are compared to social differences. I don't doubt an MRI can predict sex relatively well, but a far more accurate prediction can be based off of what type of underwear you wear and whether you carry a purse or a wallet. The social constructions and stratifications we have made for ourselves are far more powerful than differences in our own genetic code. It's largely this ability to modify ourselves through society that differentiates us from other animals.
- darawk 8y ago
  > I'm not saying that there aren't differences, I'm just saying they are practically negligible when they are compared to social differences. I don't doubt an MRI can predict sex relatively well, but a far more accurate prediction can be based off of what type of underwear you wear and whether you carry a purse or a wallet. Do you base that conclusion on a careful reading of the empirical evidence? > The social constructions and stratifications we have made for ourselves are far more powerful than differences in our own genetic code. It's largely this ability to modify ourselves through society that differentiates us from other animals. Tell that to someone with Down syndrome. Genetics are quite powerful.
  - speedplane 8y ago
    > Do you base that conclusion on a careful reading of the empirical evidence? Since the industrial revolution humanity has changed so quickly to become practically unrecognizable to those who came before it. A "careful reading" of Darwin, Dawkins, or any credible geneticist explains that is not even a blip in the genetic timescale. How could you explain that change with genetics alone?
    - darawk 8y ago
      Nobody is talking about differences from humans now to pre-industrial revolution. We're talking about differences between the sexes - an evolutionary pairing older then the species itself.
belorn 8y ago
An interesting similar study was one where they did the same scans on transsexuals. Those found that the MRI predicted the gender that the person identified with rather than the one they were born with.

dandare 8y ago

The nature vs nurture debate is not new. Do you have any evidence for your "ridiculously outweighed" claim? From Wikipedia: "Early studies of intelligence, which mostly examined young children, found that heritability measured 40–50%. Subsequent developmental genetic analyses found that variance attributable to additive environmental effects is less apparent in older individuals,[45][46][47] with estimated heritability of IQ increasing in adulthood."

sadris 8y ago

Everything you said was incorrect. There isn't a single trait ever examined in which the impact of shared environment is larger than the genetic impact. In other words, the heritability of every trait ever examined is vastly larger than the effect of the shared environment (nurture). It's literally the second law of behavioral genetics: The effect of being raised in the same family is smaller than the effect of the genes. And about evolution, also wrong. We have evolved 100x faster in the past 5000 years than in the Pleistocene. https://en.wikipedia.org/wiki/The_10,000_Year_Explosion https://en.wikipedia.org/wiki/The_10,000_Year_Explosion People like to believe in falsities like yours because they don't want to admit than ability is mostly innate and there's nothing we can do about it.

belorn 8y ago
Most people misunderstand heritability, but there is an excellent video I can recommend by professor Robert Sapolsky: https://youtu.be/RG5fN6KrDJE?t=2427 https://youtu.be/RG5fN6KrDJE?t=2427 A common finding is that if you want to explain data around a trait and you can only know the environment or the gene, the environment is usually the better choice. The interaction between genes and traits is very counter intuitive for most people. As an example from the lecture, if we asked people how heritabile the number of fingers a person has we would expect the answer would be 100% since it is very rare for a person to be born with 4 fingers. But if we asked if genes or environment is the best method to explain why some people have 4 fingers, genes are a very proof explanation since finger amputation are caused very rarely from genes. The variation of fingers among humans has thus a very low (almost 0%) heritability. Heritability == the observed variation in the data set that can be explained from genes.
- sadris 8y ago
  Correct. That's why I explicitly said shared environment (the "nurture") and not all environment (which includes non shared environment). When comparing nature vs nurture it's going to be always nature. When comparing total trait variance, the genetically explained variance is on average 50% (averaged across all traits). A fraction of the remaining 50% is non shared environment (randomness) and a minute/neglible amount is shared environment (nurture).