Anonymous asked:
sigmaleph answered:
cousin marriage is icky
doesn’t make it wrong, but
I’ve been reading about leptin receptor deficiency recently, which is mostly (only?) observed in children of cousin marriages. Stephen Guyenet describes affected children as follows:
Usually they are of normal birth weight and then they’re very, very hungry from the first weeks and months of life. By age one, they have obesity. By age two, they weigh 55-65 pounds, and their obesity only accelerates from there. While a normal child may be about 25% fat, and a typical child with obesity may be 40% fat, leptin-deficient children are up to 60% fat. Farooqi explains that the primary reason letpin-deficient children develop obesity is that they have “an incredible drive to eat”…leptin-deficient children are nearly always hungry, and they almost always want to eat, even shortly after meals. Their appetite is so exaggerated that it’s almost impossible to put them on a diet: if their food is restricted, they find some way to eat, including retrieving stale morsels from the trash can and gnawing on fish sticks directly from the freezer. This is the desperation of starvation […]
Unlike normal teenagers, those with leptin deficiency don’t have much interest in films, dating, or other teenage pursuits. They want to talk about food, about recipes. “Everything they do, think about, talk about, has to do with food” says Farooqi. This shows that the [leptin system] does much more than simply regulate appetite - it’s so deeply rooted in the brain that it has the ability to hijack a broad swath of brain functions, including emotions and cognition.
Marrying your cousin is like winning access to a whole new, much more interesting tier of genetic diseases.
Cousin marriage, according to wikipedia, has about the same risk of congenital disability as giving birth to a child over age 40. If lots of people marry their cousins, the risk gets worse.
I suspect that even if cousin marriage is legalized and destigmatized most people in the US aren’t going to want to do it, because family really isn’t that important in our culture. So banning cousin marriage implies that one should also ban giving birth over the age of 40. While that might be intractable, banning assistive reproductive technology to mothers over forty (or even forbidding it to be covered by insurance) would be more doable.
So, that things about older age being a risk - is it due to changes in uterus or genetic composition of eggs? Because if the latter, then insurance should just cover egg preservation starting right from puberty, and IVF afterwards. Not only would that solve the dilemma of “have children early due to health reasons” vs “have children late for social and personal reasons”, but it would also make voluntary sterilization to avoid unwanted pregnancy a much easier and common choice, since it wouldn’t actually be preventing people form having biologically related children later (and will hopefully put all this “but what if you marry, etc.” gatekeeping to the rest for good).
Technically, banning cousin marriage on those grounds implies that you should ban marriage to people over 40, as well as marriage to people with a high likelihood of passing on a serious genetic disorder (even if they’ve been medically sterilized, presumably).
This is the issue with arguments against incest on the basis of genetic problems: they’re arguments against having children being used to discourage people from having relationships, which doesn’t really make sense unless you’re also against non-procreative marriages generally or birth control/abortions. Unless you’re willing to say “incest between consenting adults is totally fine so long as they don’t have children with one another,” and unless you’re willing to treat anything with a comparable risk of serious birth defects the way you treat kissing cousins, it’s not really a viable line of argumentation.
It seems pretty obvious that the tendency to view incest between consenting adults as icky is an evolutionary heuristic designed to prevent genetic problems, but evolutionary heuristics are blunt instruments so we probably shouldn’t try too hard to extrapolate moral principles from them.
I want you to think about the political realities here for a moment.
Banning cousin marriage is relatively politically safe, and has been done in multiple countries without creaking up into extra categories, precisely because it is seen as ‘icky’.
Banning having children over 40 or for people with significant risk of passing on severe genetic disorders is almost politically impossible and will draw substantial criticism from disability rights advocates, feminists, and entire already-existing political structures. Previous states that have attempted this level of interference have typically been highly authoritarian and have terrible reputations.
Seeing as eugenics is now forever associated with the Nazis, even though of course having children with good genes and not condemning someone to die before the age of 40 of some genetically-passed-on heart disease would otherwise be a smart move, this matter cannot be approached directly.
In fact, even a policy of just paying people with high genetic risks not to have children based on the estimated costs to society would probably fail spectacularly on the political stage and get one labeled an Evil Nazi, regardless of one’s opinions on racial matters.
In light of this, the ban on cousin marriage should stay until the early Transhuman era. So about another 30 years.
