I've never really found a viable definition of marriage outside religious or traditional context that doesn't have some arbitrary cutoffs, I guess the parallel legally would be exclusive contracts, X agrees to buy or lease or whatever solely to/from Y, problem being, that works fine for why you can't commit bigamy without everyone involved being okay with it, it doesn't really explain why Uncle Sam has a seat at the table. Bob Johnson might agree to exclusively license his new patent to Boeing, but the government doesn't really have any business telling him he has to enter an exclusive contract with somebody. Regardless I just don't think marriage works well in a modern legal context, I've never seen a definition beyond utter libertarianism that did seem to discriminate against someone.



Well, grooming to, though it's tricky to make the case that girls who are raised to think polygamy is okay because their parents are are actually being brainwashed. Still, I can't think of any culture it is or has been common in that didn't have abuses, though other circumstances were factors too.



Yes, it's that genetic damage thing. Ignoring that sterility is an option, according to the Journal of Genetic Counseling, first cousins are only 2% more likely to have gene defects then normal, alternatively, a woman at 35 is something like twenty times, or 2000%, more likely to give birth to a Down's Baby then a 21 year old, and it's even higher beyond 35. While in the past they didn't know what the hell genes were, just had vague notions incest caused problems, we now know a lot more. If we can ban first cousins from marrying because they might have children, and ban it without an exemption for sterility, can't we ban 35 year old woman from marrying by that same logic? It's an abhorrent concept, but I can't think of a good reason beyond genetic defects and there are ways to reasonably prevent that from happening. The bans don't say "No incest marriages unless you've had a vasectomy" they say "No period", and that makes me feel we sort use genetic defects as an escape route to avoid a nasty train of thought, not because of its actual scientific and logical soundness.