4 ms·

“The study imaged the brains of more than 3,000 Americans, between the ages of 55 and 65, and found that those born in the 1970s have a 6.6 percent greater over

“The study imaged the brains of more than 3,000 Americans, between the ages of 55 and 65, and found that those born in the 1970s have a 6.6 percent greater overall brain volume than those born in the 1930s.“ 40 years is not a relevant timescale for evolution. Like it’s simply not possible for population scale changes to occur at a genetic level in one generation.

FrustratedMonky 3y ago
That is true. But it also can be faster than people realize. Everyone says "it takes millions of years". When really, you can start seeing genetic differences in just 5 generations.
3cats-in-a-coat 3y ago
You can measure changes from one gen to next. Selection occurs with EVERY generation. Small or big depends on the selection.
- bglazer 3y ago
  There are two explanations here: 1. We got richer and thus got better medical care, better food, cleaner conditions. Education got better and longer. Thus, brains grew slightly bigger. 2. Some other phenomena (?) occurred that caused a one-generation selective pressure event that culled the lower end of the brain size distribution from the population, or increased the number of high brain size individuals. I know which of these theories seems plausible and grounded in observable facts, and which one sounds like a just-so story designed to justify eugenics.
  - 3cats-in-a-coat 3y ago
    You started very well listing two theories. Where you went wrong is being immediately sure one is wrong and one is right (maybe both are wrong or both are right), being sure which is right, and excluding the possibility for more explanations, by delving into the study and how it controls for variables you hinted at. All in all, good start, but be less certain, more open-minded and pay more attention to details. I have no opinion about eugenics, other than obviously it's extremely likely it'll go wrong in the current political and cultural climate. But genes are genes, and they define us and they're constantly in flux. To reject that is basically cult-like thinking that wants to reject basic scientific knowledge in favor of some theory of morality that sets taboo on topics that are beyond discussion. I'm not a big fan of cults. They make us stupid and strive to keep us stupid. Smart is better.
    - bglazer 3y ago
      Yeah ok, open mindedness is lovely. Cults bad, got it. Which genetic variants were selected out of the population (in one generation), and how did they lead to decreased brain size?
      - 3cats-in-a-coat 3y ago
        You said "got it" but your response clearly suggests otherwise. I have no conclusions about how the particular study was concluded and what exactly it found (although there have been many studies and throughout history we've lost and gained and lost again brain mass, depending on circumstances). I said selection forcing a bigger brain would come with compromises for our health. And that noticeable changes from one generation to the next are quite plausible with strong selection bias. I said technology is cornering us and we'll be struggling to provide value unless we can compete. That's all I said. And it's all scientifically sound. Unfortunately you keep coming back to fight, seemingly, a Nazi eugenist, or whatever shallow delusion you're stuck with. I told you to pay more attention to details. This includes reading carefully what people say before you hit reply and blurt out some knee-jerk reaction. Find a better hobby, be useful to somebody for something. Time's short.
        bglazer 3y ago
        This whole thread started with you making some quite confident, and evidence free, statements about genetics. All I did was ask for any evidence for the theories you believe in. Instead you lectured me about cults and openmindedness. I would be openminded if you could give a single piece of evidence that this is genetic and not just environmental. To be frank, I don’t think you know enough about biology or genetics to know why you’re incorrect, but I would encourage you to find some neutral scientific sources and read those. Finally, you said “If we reject an intelligent system, then an unintelligent system does the selection.” The idea that eugenics is an “intelligent option” is indeed taboo, because its a wrong and foolish idea.
        3cats-in-a-coat 3y ago

FrustratedMonky 3y ago

That is true. But it also can be faster than people realize. Everyone says "it takes millions of years". When really, you can start seeing genetic differences in just 5 generations.

3cats-in-a-coat 3y ago

You can measure changes from one gen to next. Selection occurs with EVERY generation. Small or big depends on the selection.

bglazer 3y ago
There are two explanations here: 1. We got richer and thus got better medical care, better food, cleaner conditions. Education got better and longer. Thus, brains grew slightly bigger. 2. Some other phenomena (?) occurred that caused a one-generation selective pressure event that culled the lower end of the brain size distribution from the population, or increased the number of high brain size individuals. I know which of these theories seems plausible and grounded in observable facts, and which one sounds like a just-so story designed to justify eugenics.
- 3cats-in-a-coat 3y ago
  You started very well listing two theories. Where you went wrong is being immediately sure one is wrong and one is right (maybe both are wrong or both are right), being sure which is right, and excluding the possibility for more explanations, by delving into the study and how it controls for variables you hinted at. All in all, good start, but be less certain, more open-minded and pay more attention to details. I have no opinion about eugenics, other than obviously it's extremely likely it'll go wrong in the current political and cultural climate. But genes are genes, and they define us and they're constantly in flux. To reject that is basically cult-like thinking that wants to reject basic scientific knowledge in favor of some theory of morality that sets taboo on topics that are beyond discussion. I'm not a big fan of cults. They make us stupid and strive to keep us stupid. Smart is better.
  - bglazer 3y ago
    Yeah ok, open mindedness is lovely. Cults bad, got it. Which genetic variants were selected out of the population (in one generation), and how did they lead to decreased brain size?
    - 3cats-in-a-coat 3y ago
      You said "got it" but your response clearly suggests otherwise. I have no conclusions about how the particular study was concluded and what exactly it found (although there have been many studies and throughout history we've lost and gained and lost again brain mass, depending on circumstances). I said selection forcing a bigger brain would come with compromises for our health. And that noticeable changes from one generation to the next are quite plausible with strong selection bias. I said technology is cornering us and we'll be struggling to provide value unless we can compete. That's all I said. And it's all scientifically sound. Unfortunately you keep coming back to fight, seemingly, a Nazi eugenist, or whatever shallow delusion you're stuck with. I told you to pay more attention to details. This includes reading carefully what people say before you hit reply and blurt out some knee-jerk reaction. Find a better hobby, be useful to somebody for something. Time's short.
      - bglazer 3y ago
        This whole thread started with you making some quite confident, and evidence free, statements about genetics. All I did was ask for any evidence for the theories you believe in. Instead you lectured me about cults and openmindedness. I would be openminded if you could give a single piece of evidence that this is genetic and not just environmental. To be frank, I don’t think you know enough about biology or genetics to know why you’re incorrect, but I would encourage you to find some neutral scientific sources and read those. Finally, you said “If we reject an intelligent system, then an unintelligent system does the selection.” The idea that eugenics is an “intelligent option” is indeed taboo, because its a wrong and foolish idea.
        3cats-in-a-coat 3y ago