> I'm not sure why
Taboo because we discovered heredity. Legal because this isn’t prevalent enough to merit national attention.
Taboo because we discovered heredity. Legal because this isn’t prevalent enough to merit national attention.
The real reason we stopped marrying cousins is:
1. We started to live in large cities instead of on farms and ranches. (https://www.census.gov/population/censusdata/table-4.pdf)
2. We could reasonably travel more than 10 miles from home in a day.
In other words, we used to marry cousins because it was too difficult to find better prospects.
Perhaps in the majority groups in the West. Certain communities in the UK still widely practice cousin marriage and suffer hugely in genetic abnormalities. They are not constrained by transport, it is a cultural thing that has not yet been updated.
Why that's true: The reason inbreeding is bad is that the child is at risk of inheriting two copies of a nasty recessive mutation, in a region of their genome where both versions came from the same recent ancestor. However, if the child goes on to successfully reproduce, it's more likely that they had zero copies than two--and in that case the grandchildren have zero copies, which is good for them.
http://www.dailymail.co.uk/news/article-1392217/Muslim-outra...
It's noteworthy that it's simultaneously socially unacceptable to criticize Pakistanis for their preference for first cousin marriages, despite the undeniable harm caused by it, and yet it's also socially unacceptable for whites to have the much less incestuous preference for just marrying other whites, despite the absence of harm:
http://www.slate.com/articles/news_and_politics/politics/201...
> Baroness Flather said because of 'inbreeding', members of the ethnic group are 13 TIMES more likely than the rest of the UK population to have disabled children.
> The Pakistan-born peer has called on the Government to take steps against the issue of unions between close relatives in Muslim communities, which she called an "outdated, un-British custom".
...
> She also accused Britain of a "cowardly reluctance to tackle damaging social practices within certain ethnic minorities".
> In what has been described as a brave attempt to break a taboo she said there was a fear of "accusations of racial prejudice" which has made the issue "unsayable".
> She added: "That is certainly what happened over the disgraceful sex-grooming scandal in Rotherham, in which the civic authorities, including the police and social services, tried to cover up the systematic abuse of more than 1,400 vulnerable girls by predatory gangs of Pakistani heritage men."
http://www.bbc.co.uk/bbcthree/article/6af25e7b-0545-42ba-a6f...
http://www.bbc.com/news/uk-england-leeds-23183102
http://www.independent.co.uk/life-style/health-and-families/...
http://blogs.jpmsonline.com/2015/12/07/cousin-marriages-a-pu...
https://www.ua-magazine.com/first-cousin-marriage-doubles-ri...
Humans unfortunately tend to accumulate negative mutations more easily. Though the upside of lack of predation etc is not something I would want to pass up personally.
No, this is not the reason. Plenty of societies had very strong norms against cousin marriage centuries ago -- from memory below 1 percent in colonial new england?
Others did not. Sometimes because they were just far from the enforcers of such norms. But often for deliberate reasons of keeping family and property together. Saddam Hussein wasn't short of private jets, but was very concerned about losing power, and blood relatives are more reliable. And about 50 percent of his countrymen feel the same way.
Interesting factoid: Freud was married to his first cousin.
It's partly because of misunderstood heredity dangers, but mostly because of increased social pools. (Cousins used to be very socialized with each other, but strangers of opposite sex had minimal opportunities for meaningful interactions.)