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?

It is legal to marry a cousin and I think it always has been. Maybe you know people who think it’s wrong- who are they?

I’m not sure about socially unacceptable, but it can cause heart issues in offspring

Maybe as time has gone on and our knowledge and science has improved, as a society we understand it is perhaps the more wiser choice health-wise to avoid marrying or having a relationship with a cousin. I know a couple who are cousins and two of their three children died due to genetic issues.

It isn't so much as unacceptable as too risky.
Consanguinuity of kin can cause genetic defects
Plus, you only are marrying into the same family - how boring. You MN posts re the MiL will in effect, be about your aunt!

I think people have realised it’s not the best idea due to the risk of birth defects caused by not diversifying the gene pool enough

My former in-laws were cousins, married in the 1950s. They adopted two DC rather than having their own.

I don't think it means first cousins.

(Maybe it does, I'm just guessing. But I think the medical issues from close genetics were well known by then)

I met someone who was married to her first cousin. It was both of their second marriages and they didn't have children together but I thought it was icky. They only had 3 sets of grandparents between them not envy

My great grandparents were first cousin's (married in 1920s). My Granny said it wasn't something you did by the 1950s (first cousin frowned upon, second cousin considered acceptable). According to my Granny her parents had a very happy marriage.

I have Indian heritage and recently discovered it’s super predominant and popular in the southern parts to marry first cousins and uncles! They have this weird concept of cross-cousins where the children of opposite gender siblings can marry each other. And uncle-niece weddings were so acceptable and encouraged (less common nowadays only due to widening age gaps) that the local term for FIL and MIL is uncle/aunt (many Indian languages have specific terms for mum’s brother etc)!

Yes- the term cousin was often more loosely applied- could be a second cousin or cousin once removed. I met my second cousin at Uni- had never met him before. If I hadn’t known I wouldn’t have known IYSWIM. Wasn’t getting “kinship” vibes.

Like many others, I think it was when we really understood the risks.
Also remember cousin has historically used for many distant relatives not just first and second cousins.

Perhaps choices were limited back in the day? Few people travelled or knew anyone outside their community so options for pairing up narrowed.

Although even in the 21st century in some communities cousin marriage is still common and health issues sadly widespread.

Yep I think it is more that lots of people had more cousins 100 years ago - bigger families, and people moved about less so cousins (including second cousins, second cousins once removed, etc) could make up a fairly large part of your social circle.

DM went to school with several first cousins and met her second cousins regularly. I see my first cousins maybe once a year, and have no idea who my second cousins might be (in fact I could be married to a second cousin now and I wouldn’t know).

I should add thatI heard about this in the most tragic way - counselling some friends who’d gone through severe sexual abuse at the hands of their cousins and uncles since they were considered sexual property anyway and could be married off to these ghouls if they complained.

It's still acceptable in some ethnic communities including my own and that's why they have higher rates of genetic diseases.

Charles Darwin married his cousin and then regretted it after his work on genetics. I think from then onwards it was viewed as risky.

There are (first) cousins who married in my family, wedding would have been in the 1940s so similar time to your book. I don't know how people felt, always felt too rude to ask that generation and they are long dead now.

Yes I think it is quite socially ...eyebrow raising now, in my circles at least.

When we realised how much of a bad idea it was genetically.

It could be worse...

http://news.bbc.co.uk/1/hi/wales/8382869.stm

"But as the roots of his family tree are probed further, the secret about his maternal great, great grandmother, Athaliah Parrish, is revealed.

Ms Smith tells him: "From what I've been told, the daughters took over the roles of the mother when they died, and they took over all the roles of the mother. It was quite common as well."

The genes of cousins are still pretty close, so can cause health conditions, which might be why its starting to get questioned from a social perspective as awareness of these risks are increasing due to social media. But it's not breaking the law to marry a cousin.

First cousins share 12.5% of their DNA. That's really high and can lead to genetic issues in any children.

I came to say that too.

It wasn’t uncommon until it was realised that your children could be born with genetic disorders.

Also, as previously said, cousin used to be a very loose term. I read an account of an event from the mid 1800s. Two women met and got to talking. They realised they were from the same town in Ireland. From then on they referred to each other as cousin. They had no blood relation. It’s not unlike how now many people use Aunty as an honorific.

Why don't you think it means first cousins? It's legal in the UK to marry your first cousin.
However it has been proven that there is much more likelihood of genetic problems caused by that, so medically inadvisable.
I heard an interesting programme about this on the radio, cousin marriage is still very common in certain Asian communities in the UK and studies have shown that the incidence of medical problems caused by generations of this is significantly higher than other communities, yet there has been a reluctance to tackle this because of worries about negative approaches to cultural behaviour. But now those communities are being advised against cousin marriage due to the health risks for their children.
I'm 60 and remember about 40 years ago a local farmer's daughter married her cousin, it caused a bit of a stir and was generally thought of as very strange and having an almost incestuous undertone. Never known of any other cousin marriage.

Whether we were related was the very first question the pediatrician we were asked when DD1 was developmentally delayed.