4 ms·

I'm extremely skeptical of the claim that male aggression is purely environmental. Higher aggression in males is seen in many species of animals, and it is seen

I'm extremely skeptical of the claim that male aggression is purely environmental. Higher aggression in males is seen in many species of animals, and it is seen even in mouse models where they are kept in an extremely controlled environment with little socialization. There are plenty of mouse studies out there showing significant differences in brain development between the mouse sexes as well. This article is clearly presenting a single sided perspective on a complicated issue. It is also not a simple "do less harm" sort of thing - in order to one day understand issues like Fibromyalgia it will be critical to study diseases from a female perspective. If one can't acknowledge biological differences (which I have seen in some circles of scientists even), it will only hurt clinical research.

financialize 5y ago
The article is about biological differences in the brain not everywhere else and it's unlikely brain wiring is specific to genders. Brains are adaptive sensory fusion organs and if there were any gender differences it would not be because of the brain but hormonal profiles. Furthermore, the starting point of all humans is female, that's why men have nipples so even men start with "female" brains.
jayd16 5y ago
A simple explanation is hormonal differences might not cause brain differences.
- caddemon 5y ago
  I'm sure the original research article treats it with more nuance, but that's not at all what the linked article is implying: "a gendered world creates a gendered brain, and not the brain itself". Further, there are plenty of studies showing sex differences actually in the brain in mice. How impactful those differences are to behavior is not well known yet, and obviously it is difficult to say exactly how that translates to humans anyway. But there are still differences that are pretty well established, for example in glial cell development. Staci Bilbo is one up and coming PI at Harvard working on glial cell research, and one of her focuses has been sex differences. Some of her work is actually on how hormones interact with these systems: https://www.icon.mgh.harvard.edu/collaborators/staci-bilbo https://www.icon.mgh.harvard.edu/collaborators/staci-bilbo Neuroimmunology in general is pretty wild and I think we will find some gendered differences there. Certain maternal immune activation mouse models of Autism only show abnormal behavior in the males. More generally I think it's accepted that there are gender differences in the immune system: https://www.nature.com/articles/nri.2016.90 https://www.nature.com/articles/nri.2016.90
- The_rationalist 5y ago
  Testosterone has been shown to not induce agressivity though.
causality0 5y ago
I'm of the opinion it all goes back to the gametes. Lots vs few. If a creatures can be extremely reproductively successful it adds weight to the success side of the success/failure equation, which in turn encourages more extreme behavior. Big risks can pay off if there exists the potential for big rewards. This results in more variation and hence a flatter curve. Averaging the same as females but more male geniuses and more male idiots. Any category that centers more toward one end of the spectrum of possibility I'd expect to see more males. Infant mortality, birth defects, high school dropouts, chess grandmasters, murderers, etc. The effect is not enormous but the further toward the extreme you go the more the measurement is going to be dominated by men.
- SamReidHughes 5y ago
  The problem with this explanation is that mammals have greater male variability, and birds have greater female variability, and the obvious cause [1] is that it depends on which side has more redundancy in their sex chromosomes. https://onlinelibrary.wiley.com/cms/asset/32d94fa6-e5a8-4c82-a35b-3ff327c0cf58/evo12224-fig-0002-m.jpg https://onlinelibrary.wiley.com/cms/asset/32d94fa6-e5a8-4c82... [1] Well, I have to say, it was obvious to me, back in middle school, though I didn't know about the mechanics of X chromosome mosaicism at the time. It'd have been pretty weird if none of the information used to construct the brain was on the X chromosome.
  - causality0 5y ago
    Interesting. I wonder how that's influenced by the fact birds have specific reproductive seasons and 90% of bird species only take a single mate per season. A male bird doesn't really have the possibility of being hundreds of times as reproductively successful as another male bird.
    - SamReidHughes 5y ago
      Well, the evolutionary split on that difference is a long time ago, so the causality could only be in the opposite direction. It'd be pretty neat if there was a large relationship between sex chromosome size and species' mating patterns.
david38 5y ago
Well, physical aggression is far more common in males. Social assassination is more common in females.
belorn 5y ago
I would heavily recommend the aggression lectures by Robert Sapolsky if one is interested into digger deeper into the finding that among most species of animals, higher aggression is typically found among males. Among the answers, one is the human language and the bias we carry with us. Female aggression is commonly treated very differently from male aggression. A mother bear protecting her young is seen as nurturing and protective, while a male bear protecting his territory is seen as aggressive and wrong. From a biological perspective both are just behavior in favor of protecting their reproductive success, but the human bias makes it look from our perspective as very different behaviors. Further differences in reproduction can also be associated with behavior. In species where females will only mate with a small percent of males, the result tend to be males that biologically is more focused on sexual competitiveness with other males. In pair bonding species where male and female reproductive success is more identical, you get almost no finding of male aggression. Testosterone was historically thought as triggering aggression, but in more modern time it has been established that the primary association with aggression is its ability to modulate how much energy is spent on behavior towards keeping social status. In non-pair bonding species, males who suddenly gain social status need to capitalize on it in order for reproductive success, and thus spending reserved energy and taking higher risk when their social status is challenged makes for a higher reproductive success. Females do not in general have this pattern. Neither of the above imply a meaningful difference in male and female brains, or at least not in the term of cause and effect. It is also not purely environmental, through if we were to associated weight to them then environmental factors hold a more prominent role. Change how culture managed social status and the behavior change of testosterone will change with it. Apply culturally a more rigorous definition of female aggression and fewer differences between male and female aggression will be found. That said, biology bias culture, so if one want to understand behavior then both is critical concepts to explore.

financialize 5y ago

The article is about biological differences in the brain not everywhere else and it's unlikely brain wiring is specific to genders. Brains are adaptive sensory fusion organs and if there were any gender differences it would not be because of the brain but hormonal profiles. Furthermore, the starting point of all humans is female, that's why men have nipples so even men start with "female" brains.

jayd16 5y ago

A simple explanation is hormonal differences might not cause brain differences.

caddemon 5y ago
I'm sure the original research article treats it with more nuance, but that's not at all what the linked article is implying: "a gendered world creates a gendered brain, and not the brain itself". Further, there are plenty of studies showing sex differences actually in the brain in mice. How impactful those differences are to behavior is not well known yet, and obviously it is difficult to say exactly how that translates to humans anyway. But there are still differences that are pretty well established, for example in glial cell development. Staci Bilbo is one up and coming PI at Harvard working on glial cell research, and one of her focuses has been sex differences. Some of her work is actually on how hormones interact with these systems: https://www.icon.mgh.harvard.edu/collaborators/staci-bilbo https://www.icon.mgh.harvard.edu/collaborators/staci-bilbo Neuroimmunology in general is pretty wild and I think we will find some gendered differences there. Certain maternal immune activation mouse models of Autism only show abnormal behavior in the males. More generally I think it's accepted that there are gender differences in the immune system: https://www.nature.com/articles/nri.2016.90 https://www.nature.com/articles/nri.2016.90
The_rationalist 5y ago
Testosterone has been shown to not induce agressivity though.

causality0 5y ago

I'm of the opinion it all goes back to the gametes. Lots vs few. If a creatures can be extremely reproductively successful it adds weight to the success side of the success/failure equation, which in turn encourages more extreme behavior. Big risks can pay off if there exists the potential for big rewards. This results in more variation and hence a flatter curve. Averaging the same as females but more male geniuses and more male idiots. Any category that centers more toward one end of the spectrum of possibility I'd expect to see more males. Infant mortality, birth defects, high school dropouts, chess grandmasters, murderers, etc. The effect is not enormous but the further toward the extreme you go the more the measurement is going to be dominated by men.

SamReidHughes 5y ago
The problem with this explanation is that mammals have greater male variability, and birds have greater female variability, and the obvious cause [1] is that it depends on which side has more redundancy in their sex chromosomes. https://onlinelibrary.wiley.com/cms/asset/32d94fa6-e5a8-4c82-a35b-3ff327c0cf58/evo12224-fig-0002-m.jpg https://onlinelibrary.wiley.com/cms/asset/32d94fa6-e5a8-4c82... [1] Well, I have to say, it was obvious to me, back in middle school, though I didn't know about the mechanics of X chromosome mosaicism at the time. It'd have been pretty weird if none of the information used to construct the brain was on the X chromosome.
- causality0 5y ago
  Interesting. I wonder how that's influenced by the fact birds have specific reproductive seasons and 90% of bird species only take a single mate per season. A male bird doesn't really have the possibility of being hundreds of times as reproductively successful as another male bird.
  - SamReidHughes 5y ago
    Well, the evolutionary split on that difference is a long time ago, so the causality could only be in the opposite direction. It'd be pretty neat if there was a large relationship between sex chromosome size and species' mating patterns.

david38 5y ago

Well, physical aggression is far more common in males. Social assassination is more common in females.

belorn 5y ago

I would heavily recommend the aggression lectures by Robert Sapolsky if one is interested into digger deeper into the finding that among most species of animals, higher aggression is typically found among males. Among the answers, one is the human language and the bias we carry with us. Female aggression is commonly treated very differently from male aggression. A mother bear protecting her young is seen as nurturing and protective, while a male bear protecting his territory is seen as aggressive and wrong. From a biological perspective both are just behavior in favor of protecting their reproductive success, but the human bias makes it look from our perspective as very different behaviors. Further differences in reproduction can also be associated with behavior. In species where females will only mate with a small percent of males, the result tend to be males that biologically is more focused on sexual competitiveness with other males. In pair bonding species where male and female reproductive success is more identical, you get almost no finding of male aggression. Testosterone was historically thought as triggering aggression, but in more modern time it has been established that the primary association with aggression is its ability to modulate how much energy is spent on behavior towards keeping social status. In non-pair bonding species, males who suddenly gain social status need to capitalize on it in order for reproductive success, and thus spending reserved energy and taking higher risk when their social status is challenged makes for a higher reproductive success. Females do not in general have this pattern. Neither of the above imply a meaningful difference in male and female brains, or at least not in the term of cause and effect. It is also not purely environmental, through if we were to associated weight to them then environmental factors hold a more prominent role. Change how culture managed social status and the behavior change of testosterone will change with it. Apply culturally a more rigorous definition of female aggression and fewer differences between male and female aggression will be found. That said, biology bias culture, so if one want to understand behavior then both is critical concepts to explore.