When did marrying a cousin become socially unacceptable?

[LionBird]

I'm a big Agatha Christie fan and noticed there are quite a few references to cousins being in a relationship. I'm rereading Taken at the Flood currently, which is set in 1946, and the main character is engaged to her cousin and nobody seems to think it's strange! Obviously it was quite common in royal circles too in the 19th century but post-WW2 isn't that long ago so I'm not sure how and when it became unacceptable to have a relationship with a cousin - can anyone shed some light on this?

Agree. First cousin marriages have always been relatively uncommon but second/third/fourth much more common , particularly in small, rural communities where almost everyone is related . DH’s grandparents were second cousins.

Different types of risk though I would have thought?

• older mother /father means increased risk of age related risk associated with deterioration in quality of gametes (recessive gene doesn’t find a double here)

• cousin marriage - increased risk of recessive genes associated with specific disability /delay /medical condition finding their double and being expressed when likelihood is they wouldn’t have been had the partners not been related

disclaimer: not a scientist

The distinctive Habsburg jaw comes from centuries of intermarriage between uncles and nieces, cousins, and serious intermarriage between the family.

It was not a one off cousin marrying a cousin.

Back then social pools were smaller so it was acceptable to marry cousins, more out of lack of choice. Now women have life outside home a lot more than those times. Also, people married younger. So to some degree clock started ticking at very young age and it was not that easy to meet suitable men/ women.

Some are happy to take that risk

I didn't know the names of my great-grandparents before I was about 20. Except for John Thomas and his wife Esther. I didn't know the name of the one I actually met: so far as I was concerned she was called gran-gran. (And her first name is not the name she was known by.)

My brother was good friends (as in, one of a group of 5 all through school) with someone who we discovered when they were in their twenties was some sort of connection (can't remember what now) with John Thomas through his first wife.

Oh, Esther's parents were first cousins.

On the other side, my paternal grandfather's father was married to someone else - as far as we can make out they didn't have any children, but none of us would have known if they had, and I didn't know his name until I was in my thirties. Paternal grandfather's mother then married someone else, whose surname I was vaguely aware of but it was fairly common; to the extent that there was a child in my ballet class with that name, and it was only when I was in my 50s that I wondered whether there was a connection. (Answer: no, not that I can discover)

Meanwhile in H's family, his paternal grandfather's father was a complete mystery until about 2 years ago when Ancestry hints threw up a WW1 pension record with grandad's name dob and mother's name (surname ridiculously common, first and middle combination unmistakeable).

@Alondra

The distinctive Habsburg jaw comes from centuries of intermarriage between uncles and nieces, cousins, and serious intermarriage between the family.
It was not a one off cousin marrying a cousin.

Yes I know. That was my point. If you had good genetic material, and a one off cousin+ cousin maybe it would be a good thing and result in very very good genetic offspring.

Don’t be ridiculous.

It isn't illegal to marry a first cousin but not encouraged for various reasons, some health as consanguinity can result in hereditary/familial illnesses presenting in the couple's children. Not always of course but it does happen and the Pakistan/Bangladesh community are trying to stop that because they've had a few very sad cases.

The other thing is if cousins have grown up together and are close, they are very like siblings and there's something incestuous about that.

Most of the royals who historically married first cousins (Queen Victoria and her children are examples), did not know each other much or even at all until adulthood, they often lived in other countries. However since that time they have only married distant relatives which is far healthier all round.

Why marry a first cousin anyway, the pool is bigger than that surely.

This comes across as very patronising to people older than you! It was extremely well understood long before you were born that the chance of genetic disorders is far higher in families where the parents are close blood relations. People have been breeding animals for millennia, after all. What varies over time and between different religions, ethnicities and social groups is the social acceptability of taking that risk. There are other reasons why people might think it's a positive step, to do with keeping money, land and power in the family, for example.

Iceland, from the poster mentioning it, has a population of less than 400,000 people and was for centuries isolated. Their population has a very limited DNA diverse pool, the reason why first cousin marriages are not allowed.

As others have said, it is not illegal for first cousins to marry in the UK. However, it is not a good idea have children if you are as closely related as this because hereditary diseases become more and more pronounced and problematic if inter-marriage continues over several generations. Various royal families illustrate this very well. The Hapsburgs of modern day Austria and Hungary had a deformity of the jaw, which became so bad that it was known as the Hapsburg jaw. The European royal families of the eighteenth to the early twentieth century were all related to each other and there were unusual diseases that proliferated. Porphyria and haemophilia are the most well-known. Finally, cousins marriage is still very common in Pakistani families. In towns like Bradford it is causing huge problems, because the children are being born with and more profound serious learning disabilitie.

I’m an aristocrat.

My grandparents were cousins, although they barely knew each other as children.

My father was encouraged to “marry out” and gave the same advice to me and to my siblings. One of my siblings married a second cousin they met at uni. Their children are fine, but we were all a little worried.

I’d say when we understood genetics properly and realised that marrying someone to whom your are related increases the risk.

*Disabilities.

My great grandma married her cousin but that was in order to escape a war because he lived in another country

I got chatting to a woman at a playgroup who married her cousin. Her child had global delay and other issues. When I had my babies the hospital asked if I was related to baby's dad as this is a common issue.

Some years ago there was DNA testing of the 9000 year old Cheddar Gorge Man People in the area were asked to come forward for possible matching - IF their grandparents had also lived in the area, because before that, people had generally stayed put, even over many centuries.

They did actually find a match - a local teacher who said, ‘My wife always did say I was a bit of a cave man!’ 😂

My mothers brother married their cousin (their fathers were brothers) and their only child had serious health issues. We are talking about the1920s, when it was a known fact that marriages of that kind could produce progeny with health issues. Their only child was blind in one eye and was unable to have children of her own. Very sad .

One of my Indian colleagues (living in India) would often refer to his "sisters", but i knew he only had a brother, so I asked him about it and he said that he would refer to his first cousins as sisters and brothers so in his family for certain (Hindu), a cousin would be a wider family member.

Choices were certainly limited in certain areas but this resulted in a lot more second cousin and other extended family marriages rather than a lot of first cousin marriages (at least in most cases).

I've traced my family tree back to the early 1600s and in all that time I've only come across one first cousin marriage. Although there have been a number of second cousin marriages and also the same families intermarrying over several generations meaning that there are quite a few more distant, but still related, marriages.

There is a term for this, it is called "endogamy" where the same group of families intermarry over generations. This means that the same DNA is kept within the family for a longer period of time than you would expect normally.

For example, my mum had a couple of distant relations that went over to America in the 1600s. To be frank, there were a lot of families intermarrying each other back then (the population in Maryland and Virginia was very small) and you can still see the results of that in the DNA today.

Many Americans who trace their ancestry from early US colonial families have found this when getting their DNA results. I remember somebody saying that they had colonial ancestry from Maryland and Virginia through both parents. While the parents weren't related to each other in any way over the last two hundred years, they had dozens of DNA matches who were related to them through both parents, and quite a few more who had a DNA match to one parent and a paper trail that connects them to the other.

It is not uncommon for colonial Americans, Ashkenazi Jews, French Canadians and US Cajuns to still show the results of this endogamy from centuries earlier. The same thing applies to certain communities from South Asia as well.

I knew of two sisters who married two brothers and the male / female offspring were in a relationship for a while when they were both early 20s.

They shared the same grandparents on both sides. The relationship fizzled out and are both now married to other, non related, people.
It was definitely weird, and incestuous.

I worked with a woman who had married her (first) cousin. They had several children, and all of them were very unique looking (I'm avoiding using terminology that is potentially not en vogue to describe their appearance). Massive heads/tiny ears, very long limbs.
Her husband was considerably older than her, and apparently when she was a young teen he'd taken her aside and told her they were going to get married one day; she told this tale as if it were terribly romantic 😬

Why marry a first cousin anyway, the pool is bigger than that surely.

I think sometimes it was done to keep the money within the family. Maybe still is in some communities.

I don't agree with you. DNA should come from a diverse pool of parents - there is serious research why interracial marriage is so important in the gene pool.

I've just tried to bring some reason to the discussion and why as a one off, first cousins marrying each other have similar outcomes with their children as if they were not related.