Most of the world actually has legal marriage between first cousins. In many places it’s not even taboo. And on top of that, the chances of genetic issues with it are actually pretty small. It’s multiple generations of first cousins having kids where it becomes a problem.
Apparently this taboo got started as thing by the Catholic Church during the medieval ages as some kind of property inheritance thing. I can’t remember the details. I remember watching a whole video that argued this anti-cousin marriage thing is where the West got it hyper individualism from, compared to the rest of the world, but I can’t find it now.
Step son/daughter or sibling? Is that in the laws yet?
Why should it be illegal to have a relationship with someone you’re only related to by law? I mean yeah, naturally this will rarely ever happen and it’s kinda weird to think about, but something being weird is hardly a reason to ban it.
Why should it be illegal to have a relationship with someone you’re only related to by law?
Logically only the same reason you couldn’t have a relationship with first cousins. Inbreeding isn’t exactly a problem for first cousins, they’re genetically different enough for it to not have much of an affect until multiple generations of it (plus same-sex people, sterile people, people who just won’t have kids), so the only plausible argument for it is “marriages between family members are more likely to be from grooming/manipulation/abuse”. Which I don’t think is flawless reasoning to make it illegal, same thing could be said about many other perfectly legal types of relationships. But it is a reason.