I know this is probably a weird question, but I'm genuinely curious about it. To reword my question: How far down in the family tree would two sims have to be (blood related, but distant relatives) until they could pursue a relationship without mods? I'm thinking of checking this out for myself just to do it but I'm a little nervous about corruption; though the family tree is probably the one thing that might get corrupted, right?

Unlike other people who've asked similar questions I should stress that this would be with distant relatives, a few notches down the bloodline. Not siblings or first cousins.

First cousins are "related" by the game's standards, but second cousins (and any more distant relations) don't seem to be. Not sure if a first cousin once removed is considered a relative or not...

Likewise, a great-grandchild is not "related" to their great-grandparents (except in the family tree, obviously). On the whole, it looks like a three-generation gap is what it takes.

First cousins once removed don't count as relatives in the game, either.

The game can be kind of weird about this though. I have one sim whos grandmother had a few siblings that also had grandchildren. The girl's related to the older brother's grandson, but unrelated to the younger brother's grandson. (As in, the first one shows up as family on the relationship panel and she has flirt options with the second one). I've also seen situations where one sim considered another sim family (having family interactions enabled) and the other didn't.

As far as family ties and blood-relatives go, the game really only recongnizes parents/children, grandparents/grandchildren, aunts and uncles, nieces and nephews, siblings and first cousins. Everything that has not been mentioned here, the game would often probably not even recognize as family. Though Ovenhole is right, that some may!
The family tree that the game creates, is merely for *your* review, but the game never does anything important with it... So if you tie it up in a big knot, the worst that will happen, is that the game can not show you a correct picture of this family tree. Nothing else gets corrupted and nothing breaks.

So if the game allows you to do it, don't worry about consequences, because there are none!

The game is weird in handling the not so distant relationships, but thanks to that two branches of Penhalgan family have finally reunited!

For those who don't play Polgannon: Carrow Penhaligan wasn't on good terms with his father, Blaise (the one whose murder we had to solve!), so he moved out and started the household of his own, Penhaligan 2 as I put it. No one knew how the things would turn out in future.

After Carrow moved out, got married and had a son James, his father Blaise re-married and had another son, Oliver. Carrow's son James grew up and had a daughter Aswen. Little Oliver also grew up and had son Dewi. And these not so distant relatives, Dewi Penhaligan and Aswen Penhaligan, fell in love and now have two kids of their own. This is how it looks in their family tree:



If I'm not mistaken, Carrow and Oliver were half brothers, James and Dewi - first cousins, and Aswen is actually Dewi's niece or something? Didn't stop them from getting married.

@Amairani

Aswen is the daughter of Dewi's cousin James. So they would be first cousins once removed. And that's not recognized as related in the game, therefore they can marry. It's not recognized as "incest" in real life as well. My dad and my mom were also first cousins once removed and they could get married!
In other words, my (paternal) grandmother and my mother are actually (first) cousins.

This wikipedia article may help. https://en.wikipedia.org/wiki/Cousin

I find this chart on family relationships very useful. The 'self' is whichever sim (or person) you're trying to find the relations of:



But yes, as BO said: parents, siblings, nieces/nephews, aunts/uncles, and first cousins are the only ones the game recognises. You can get mods to increase this, but that's not the point of this post

If I recall it correctly I once had two teenage cousins going steady in the game

I have such an extreme aversion to incest in this game!

In my legacy, my founder had two kids and I've been playing these two familial strands for about 22 generations now. This means that the two sims I'm playing now (who are descents of the founder) could realistically get together and it really wouldn't be that strange considering there has been so much genetic mixing over the 22 generations that led to their existence....but I still can't let my legacy family crossbreed like that! It feels strange.

I know it silly. Especially when you consider that IRL people marry 3rd and 4th cousins without consequence. Like Eleanor Roosevelt and FDR were 5th cousins I believe. It's more common than you think - I believe it's mainly marrying 1st cousins and closer that problems tend to occur (which the game thankfully doesn't allow).

@iwillnotbreak: I agree, it *is* rather silly of you. But that is a big part of the fun of the game: you can be as silly as you want; as long as it makes you enjoy playing the game the way you do, nobody can stop you from being silly.

Indeed - many cultures across the world use cousin marriage routinely - it's America that's unusual in this regard.

If you aren't scared or concerned about the physical and mental problems that inbreeding causes...
But this is IN game, and we all know there is no such thing as physical and mental problems for sims. ahah!

Meh, I've got a procreative marriage between half-siblings in my ancestry, just three generations away from me. (Don't worry, they did not know they were half-siblings until later, after they'd had their 7 kids....none of whom were "monsters," BTW. ) Miscarriage is a little more common than normal in the affected branch of the family tree, and we tend to have rare blood and tissue types, but that's about it. "Inbred monsters" only happen if the inbreeding is done consistently and repeatedly within the same family line. That's how much of the aristocracy of Europe ended up with hemophilia, for instance, since those dynasties were/are all interconnected due to politically-motivated marriages and inbreeding over hundreds of years. Not to mention ancient Egypt, where procreation between siblings and between parents and their own children was normal in the royal dynasties. It's also why "purebred" animals tend to have fertility issues, shorter lives, less resistance to disease, as well as an increased chance of physical deformities like cleft palates and hip dysplasia. But again, that's a result of institutionalized inbreeding that's done repeatedly so that the parents share the majority of their genes, not because just one person might happen to have a kid with their first cousin here and there. (Or, unknowingly, with their half-sibling, as my great-grandparents on my father's side were.)

Not that I'm advocating going out and having babies with your first cousin or anything, but in reality, aside from social taboos, it wouldn't be a problem unless you both happen to have genes that, if combined, might result in non-viable offspring and, thus, miscarriage and/or children born with deformities and/or a low life expectancy due to genetic conditions. (Which can, incidentally, also happen when the parents aren't closely related if they also happen to have non-advantageous recessive genes in common. See genetic conditions that are, for instance, more prevalent within a specific ethnicity or culture, like the prevalence of Tay-Sachs disease amongst Ashkenazi Jews who might not be closely related.) Without such non-advantageous genes in both parents, there wouldn't be a problem. Aside from social taboos, as I said.

From a legal perspective...I did a little bit of research about this because I run a neighborhood where all of the playables can trace their lineage back to one Sim, namely Benjamin Long. I have reached the point where inbreeding is allowed by the game, so I was curious about the real-world legalities surrounding inbreeding and such. I found, much to my surprise, that first cousin marriage is legal in the majority of the world as well as in the majority of US states. Second-cousin (and on) marriage is illegal nowhere. So, the game is actually more conservative about this issue than the real world is, since it will not allow romantic interaction between first cousins.

Wow. That sounds like a strange situation. Though I suppose after 7 healthy kids, there's little more one could do other than get a little skeezed out at first, shrug, and move forward. What's done is done.

Yeah, not much you can do when the milk is already spilled, as they say. According to my grandmother -- who was their last-born -- they did have two miscarried children, one rather late in term, plus there was one daughter, their second child, who died at age three. (I didn't count her as one of the seven ) But, especially at the time (this was in the 1890s into the 1910s, and all, in a rather isolated town in Wales, where my father's family is from), miscarriage wasn't all that uncommon, anyway, and infant/child mortality was high regardless, so it didn't raise any alarms or anything. Plus, it's unknown whether something like that would have happened regardless, given that they were having lots of pregnancies pretty close together, which obviously causes strain on the woman's body.

So, even though my great-grandparents on that side had the same father, apparently there was enough genetic difference and no one was carrying any terrible recessive genes (since there was no other inbreeding) so that there were no catastrophic issues involved with the birth of my paternal grandmother and her siblings. To be honest, there's more concern about inbreeding on my mother's side, since she IS European aristocracy (albeit a branch that emigrated to America in Victorian times), and...Honestly, I don't even even want to know.

In any case, all of this is why I kind of laugh when people freak out over cousins having babies and saying things like, "OMG, their children will be monsters!!" They really won't. Not unless such inbreeding has been going on for a long time in both their family lines, anyway...and perhaps not even then. So...Yeah. I certainly have no trouble with my Sims inbreeding as much as the game allows, since the concept in general isn't something I squick out over much, anyway, AND there are no genetic consequences for them. So, if one of my Sims gets the hots for their second cousin and wants to marry and make babies with them....so be it.

Yeah but that is something that seems exaggerated at times. Breeding with close-ish family members does increase problems but not as much as some people seem to think. You do notice it in large populations, of course. However, I remember reading a comment from a poster - here I think - that seemed to assume that breeding with any one closer than 5th cousin or something means that any child would automatically have some form of problem - nope. Not how it works. The fact is, even amongst first cousins, the large majority of children are just fine. If it wasn't you'd really notice it in places like India.

Incest refers to parents/children, siblings and grandchildren - anybody else is fair game.

If the game allows it I go for it if needed or wanted by my Sims.

A little late, but thank you all for the replies. I've wondered about this for a while, and I think I'll give it a go to mix things up, considering there won't be any terrible consequences---as said by BO.

Just to chime in on the "real world consequences" thing... Third cousins (with no history of inbreeding in the family) have the same chance of genetic problems as a random couple who aren't related. First cousins having kids only increase the chances of genetic issues by the same amount as having children at 40 rather than 25 - and no society tries to stop 40-year-olds having babies! Multiple close relative marriages in a family is the risky part, but even that is only a risk - one part of my family tree has about 5 first cousin marriages over 150 years or so, but we've all turned out normal (or at least, fairly normal )



Mostly, this is correct, but haemophilia isn't a good example since haemophilia in men is just caused by a single gene. It showed up in multiple royal families throughout Europe purely because Queen Victoria's descendants ended up there, not because they married their cousins. If the last Tsarina of Russia had married someone not related to her, her sons would still have the same chance of having haemophilia.

It's certainly true that a lot of the infant mortality and miscarriages suffered by European royalty were caused (or at least affected) by inbreeding, which is why various kings' bastard children were so often healthier than their legitimate children

@KittyCarey

You're right, the hemophilia probably wasn't the best example. It's merely a sex-linked trait, not something caused by inbreeding...although the fact that it was so widely prevalent across Europe -- and all traceable back to Victoria and her daughters -- does show how "linked" the royal dynasties of pretty much every European country is and has been for hundreds of years. But, to be more accurate, we could talk about the Habsburgs. But then we'd be venturing wildly off-topic, even though it IS a topic that's interesting to me.

But yeah, while repeated institutionalized inbreeding is bad in the sense that you reduce genetic diversity (which is also the reason that eugenics is also a Very Bad Plan, even without the discrimination and occasional bouts of genocide that such thinking incites) which can cause fertility issues and an oddly-high rate of genetic conditions and physical deformities and intellectual deficits and decreased resistance to disease and on and on, people do freak out about it far too much. I mean, I understand the social taboos and all but, in the grand scheme of things, those taboos are very new and only exist within certain cultures. Really, if procreating with your first cousin was such a terrible, awful thing, then many countries/cultures -- like India, as maxon pointed out -- would be in serious trouble and, in fact, I'd say that it would be unlikely that Homo sapiens would still exist, as I'm sure LOTS of inbreeding happened when humans existed as small, isolated-from-each-other nomadic tribes.

You all 'bout this again? That's like a curse or obsession... *Apage!*

We're obsessed? This is the first time I've ever gotten into a discussion about this topic and, really, the first discussion I've seen on the subject. But then it's not like I get around in the community very much.

In any case, we were discussing strictly the possible real-world genetic/biological consequences of inbreeding and how those are usually greatly exaggerated in most people's minds, since it was brought up in the course of a discussion about to what degree the game will see two Sims as related. No one was talking about the ethics and/or legality of such situations in the real world, aside from me saying that in the majority of the world first-cousin marriage (and, it's assumed, procreation) is legal. Laws regarding incest between people more closely related than first cousins exist because, in modern societies, a sexual relationship between, for instance, a parent and their own offspring is seen as an abuse of power, even if the offspring in question is at or above the age of consent. Such laws really don't "care" about the biological consequences involved at all. So yes, two completely different things but, to date, we'd only been discussing the biology involved, not the laws/ethics.

Ouh, yes, "We" (like the Borg) "are", and the resistance is futile (and who never made something weird in his/hers game then will 1st use the stone)