No form of incest is any longer "actively encouraged" in most parts of TN
Well this wasn't the case up until recently. TN culture historically encouraged & romanticized first cousin marriage for a long time. Doesn't matter if people in cities stopped doing it now. Their parents, grandparents & great grandparents did it for so long that recessive genes got passed down through multiple generations & chance of expression of undesirable traits spiked in their civilization.
one of the more developed & literate (80+%) states of our country
Has nothing to do with the problem at hand. TN as a society remained uneducated on the topic of inbreeding & potential risks, for a long time.
So nothing extreme or irrational about first cousin marriage being a social taboo at all
Depends on what kind of society we're talking about. If it's a society that's uneducated on this particular topic & keeps romanticizing the idea of first cousin marriage, yeah then you got something to worry about. Bcoz there is a good chance that sequential inbreeding will occur throughout multiple generations, leading to spike in recessive gene expression rate in newborns. But if we're talking about a society that's educated on the topic & does not have a habit of inbreeding, then there's nothing wrong if two cousins happen to fall in love/date. Yet, American culture stigmatizes it to a level where a random first/second cousin couple can get shamed for it, it's just unnecessary. At that point they are just using phony science to justify their beliefs