Groups that isolate themselves from the broader culture even though they live in its milieu also have higher intermarriage. The Amish in the US have become notorious for having much higher instances of genetic disorders than the broader German-American community. The Amish receive very few converts and almost all of them are descendants of German, Dutch, and Swiss refugees who arrived in North America hundreds of years ago and have spent the past 300 years boinking their second cousins <3. Your typical German-American circa 1850 might have married a new immigrant from Germany, a French-Canadian, Irish-American, or really any random white person and nobody would really care. The Amish did care and discouraged their followers from doing so.
Good point. I think the origin of the term “cretin” came out of the same thought that leads people today to say things like “The disabled are people too!” Nowadays we prefer to speak of people or humans rather than assuming everyone is Christian, but the idea is the same - that we (the “normals”) are the same fundamentally as the disabled.
Here’s a summary of the prevalence of consanguineous marriages for various countries:
The Westermarck effect is accepted generally as being one of the things that effectuates this.
My only female first cousin is far younger than me and I must admit to being thoroughly disgusted by the idea of her in bed. Her in my lap is another story, but she’s now too big for that. One bonus of this is that I can help her get dressed for formal, fancy events because I can have my hands all over her without shaking or feeling horny.
I don’t think it is fair to call it a southern thing because some of the finest people I know have come from the south. But there does seem to be a sub culture that exists in the south of uneducated poor whites where incest is pretty common. I know of one case where a man had children by his daughters and then his grandchildren who were also his daughters and then his great grandchildren wo were also his daughters. The girls just stayed at home forever and the boys seemed to leave at about 16.
…or zombies.
The further you go back, the more likely you are to find a link. I’m a descendant of a Mayflower passenger, an early polygamous LDS (Mormon) bishop, and two of the founding families of a medium size US Midwestern town a few hours from Chicago. I’m probably related to dozens of people on this site.
Because prejudice against poor Southern whites is “okay”.
Hey coz … so what are you doing Saturday evening? 
Descended from Mayflower on my Dad’s side[so is mrAru, we figure we are cousins back in about 1820 the most recently] and I have tons of relatives that way, just way back. Mom was Amish, with their own version of inbreeding issues. At least with those two 2 family histories they married pretty nonconsanguinly.
Actually, for about 8 years we had a friend who was also stationed on mrAru’s shore duty and one of his subs who was from Tennessee who really had the hots for one of his cousins and he had originally met her at a family reunion :smack:
A really awful incest case was just recently discovered in Australia.
Well maybe, but this would seem to depend a lot on how you’re counting. 7 of the 11 states which were in the confederacy allow 1st cousin marriage. 13 of the remaining 39 states allow it. So that’s more but a much smaller percentage.
Was this man’s name, Craster?
My goodness!
I have heard tales of first cousins marrying in my family a couple of generations ago, but my paternal great-grandfather stopped the practice and his word was law in those days.
I think that joking about incestual relationships is probably a worldwide phenomenon.
I live in a fairly rural English county. Locally we make jokes about a small town, just over the border in the next county.
“At most weddings there, everyone sits on the same side of the church.”
“A virgin is a girl who can run faster than her uncle.”
From a Swedish point of view, no we don’t. Norway, on the other hand … 
I’m going to suggest isolation as the cause.
While initially, the obvious isolated areas were deep Appalachian valleys, over the centuries the south until recently stagnated while the north expanded with industrialization. Factories sprang up all over the north, new immigrants flooded in continuously, and there was population turnover. While the north was continuously attracting new people, the south was one of the places these people were from, leaving behind smaller groups who had to choose spouses from smaller pools of eligible. I suppose to some extent the same might apply to more remote northern villages, or villages that were created wholesale by one group during the immigration rush. But generally, I suspect the interbreeding meme applies to backwaters where not a lot of people come or go; or with large families, all most people do is go, so the pool gets progressively smaller.
IIRC the degree of common genetics for first cousins is about 3%; hardly much risk of creating doubled-up bad genes. However, mix and match the same pool for centuries, so everyone is a cousin 10 ways through multiple unions, and you will find that you are creating a much higher risk of genetic problems.
The Arabs do tend to marry cousins and second cousins, but really what you have are a number of “tribes” or clans - everyone in a tribe is related, going back generations, several ways; and tend to not cross-marry to other tribes, although it happens. This creates strong support bonds, in a place where the only people you can count on to defend you and your family (or support them in time of need) are your tribe. One article I read, for example, suggested that a lot of what we see in the Gaza as political beliefs and sectarian violence is actually tribe vs. tribe power struggles.
The pharaohs of Egypt may have practiced incestuous marriages - the practical side of this, like the European model, was it kept the divine blood more closely limited, reduced the number of additional claimants to the throne, reduced the redistribution of the family wealth, etc. The pharaohs were not dummies though - they also had concubines or extra “wives”, and as often as not, the designated heir was from a secondary “wife”. The relatives simply could not claim to be relatives of the official “Queen” and thus their claims in any civil strife were more limited.
Why white trash? Well, until the civil war, most slaves probably could not give a coherent and properly recognized family tree; they were also mixed and matched from far and wide without regard to niceties like introductions or matrimony - so when you’re starting with a blank slate in 1865, by 1950 odds are there’s not a lot of family overlap yet. Also, white society generally probably did not socialize enough to hear (or care about) any stories of who was married to their cousin.
As for incest as in father-daughter or brother-sister; this is (from the news) a fairly common problem, especially when the regular social norms have broken down. This typically happens in the dregs, or in very isolated areas, outcast families, etc. where the rest of society does not visit or interact enough to see what’s going on and put a stop to it. But generally, it is always taboo.
–unless the jokes involve sheep.
Why do Scotsmen wear kilts?
Sheep can hear a zipper at a hundred yards…
Country bumpkins of whatever type have been the butt of jokes for centuries or millenia.
The more identifiable (ethnic, accent, backwardness, dress funny, whatever) the more distinct and hence the more ridiculed for some trait or other.
Because it was first associated with the highly isolated people in the Appalachians and Ozarks. Isolation can breed (no pun intended) some too-close family relationships, inadvertent or not. It’s simply hard to find a mate that’s not related to you when you live in a small town deep in the mountains miles from the next one - sometimes you don’t even realize someone is your second cousin or whatever. It’s like the old famers who are so lonely and desperate that they screw their sheep myth.
From there, it became associated with poor “white trash” in general.
I have some family from W. Va. myself. I was looking at a family tree an aunt of mine made. I was amused to find her father’s side’s rather unique name a few generations back on her mother’s side too. Her response: “Well, this is West Va. after all.”
P.S. Now I see someone else has given a similar answer already on this same thread. See what I mean? It’s hard to avoid incestuous relationships. 
I hear a lot of incest occurs in isolated rural communities here in Trinidad, and it isn’t associated with poverty per se. I mean there are poor urban communities piled into apartment buildings subsidized by the government, but there is no talk about incest there. At the end of the day it is the isolation and lack of law enforcement that allows this abuse to thrive.
Basically in isolated rural areas and farming communities there is very little law enforcement, it is a paradise for sexually abusive parents. Also the isolation keeps talk from spreading, in a more active area people would start talking about the weirdo who is too touchy with his teenage daughters. Or his daughters would go to the police, or someone else would call the police. But out in the country there are few cops, and what few are there are likely to be complicit in covering this crap up.
I just don’t think it is poverty, it is the isolation.
Totally off the top of my head I think it was to do with allowing step relatives to marry.