Something that I find cool as a biochemist is how there are traits that are good for a community that may not be good for individuals. The most straightforward example of this genetically, is sickle cell anemia.

Sickle cell anemia is a genetic disease that results in blood cells having a sickle shape, and a lower oxygen carrying capacity. It’s a recessive condition, which means you need to have inherited the sickle cell trait from both your parents to have sickle cell anemia. If you have inherited the trait from only one parent, then some of your blood cells are sickle shaped, but you’ve got enough regular blood cells that you’re considered just a carrier of the sickle cell trait. I had a friend who learned she had the sickle cell trait when she was a high level athlete, because that was a context where her blood’s somewhat reduced oxygen carrying capacity was relevant. She might’ve never known otherwise.

Something interesting though is that the parasite that causes malaria struggles to take hold in sickled blood cells - someone with full sickle cell anemia has like a 90% risk reduction for severe malaria [citation needed]. This means that in places where malaria is common, such as sub-Saharan Africa, the sickle cell trait offers a selective advantage against malaria and is thus more prevalent in these areas.

People with full sickle cell disease (inherited from both parents) still suffer from the various health problems associated with the condition, which leads to lower life expectancy, especially in areas that are most heavily hit with malaria. However, people with one copy of the sickle cell gene experience some of the protective effect against malaria, without the significant health impact of full sickle cell disease.

[Caveat, It’s been a while since I learned this, medical prospects and practice, especially around the risk of malaria, has likely changed somewhat since then]

In practice, what this means is that all in all, it’s probably not a net advantage to have sickle cell disease, even in an area with high malaria rates. However, it is beneficial for people to have the sickle cell trait. If two people who both had the sickle cell trait had a child, there is a 25% (1/2 * 1/2) chance the child would receive two sickle cell traits and have sickle cell disease, a 50% chance they’d be a sickle cell carrier, and a 25% chance of not carrying any copies of the sickle cell trait. A trait can be good when it’s circulating in a community, even if that trait can cause a pretty severe disease.

I find this interesting because it’s a real, grounded example of how diversity makes communities stronger. I think about this a lot when it comes to autism and ADHD. I wonder to what extent we might be “canaries in the coal mine”, so to speak, unable to fit into a broken system and helping to illuminate how broken it is. A concrete example of what I mean is how a common autistic story is making extended family unhappy when resisting giving them a hug or a kiss goodbye. I used to run away and my mum would tell me off for being rude. Looking back in hindsight, I’m like “lol, so autistic of me, the benefits of hindsight”, but I’m also thinking “wow, the way we teach consent to children is fucked up, I’m glad for the ways in which being autistic has made me resistant to some of these things”

Something I love that has shaped my views on this a lot is this paper by Rosemarie Garland-Thompson, about “misfits” and disability theory. It’s fairly readable, by the standards of most academic papers, but it’s still pretty chonky, so I can share with you some of mt favourite snippets if you’d like

you want mentats? that’s how we get mentats.