Back when I used to do pedigree analysis, the general rule of thumb was 1/10 chance that the father wasn't what was stated in the pedigree.
You would run the analysis and get absolute nonsense results, and then you'd swap a father for an uncle, or a mother for her daughter, and the alleles would all just suddenly line up.
We would never tell the families, and since the pedigrees were anonymized before being published there was no need to. Some secrets are just best kept buried.
What is nuts is that in some countries, its illegal for the father to unilaterally have a paternity test done. I know for France that if you have it done unilaterally and thus illegally you are still on the hook for child support until a legal test is done, which either the mother needs to agree to or needs to be agreed on by the court.
IMO a paternity test should just be mandated to be done immediately at birth (or earlier even?). It avoids the tinge of distrust of "oh wow, how could you even think that of me?!" from the mother, whilst giving certainty to the man.
In most countries, including France, you are on the hook for child support if you named yourself as a parent. In France you may contest it by applying to court during the first five years, after that only a prosecutor can take the steps to revoke that status. Between the unfairness of making an adult pay for a child who isn't theirs, and that of throwing an innocent child into financial distress, protecting the child takes priority everywhere I know of.
>Between the unfairness of making an adult pay for a child who isn't theirs, and that of throwing an innocent child into financial distress
As others have stated above, this isn't really about protecting "family harmony" / "saving the child", it’s about cost.
If paternity tests were easily accessible, many men would easily contest child support and if successful, they would opt out. The state benefits from keeping paternity disputes out of court because it ensures that private individuals, rather than government welfare programs, remain responsible for child support.
If too many men successfully challenged paternity, the state would be forced to provide financial aid for more children, increasing costs. Restricting paternity tests shifts the burden away from taxpayers and onto unwitting fathers, all while claiming it’s about social stability.
>Between the unfairness to make an adult pay for a child who isn't theirs and the unfairness to throw an innocent child into financial distress, protecting the child takes priority everywhere I know of.
I wonder how would you react if you received a notification that half your paycheck will be henceforth withheld to support some random kid.
this comparison is not entirely fair, because in this scenario, the kid's mother did not deliver a grievous, unforgivable insult to you - which is the case with those poor souls who got scammed into paying child support for some whore's bastard whelp.
the state doesn't give a flying fuck about the child's 'financial distress'. the state simply doesn't want to support it.
That's where French law actually makes sense: after 5 years, it's your kid, even if not biologically, not a random kid. I don't think I would be chuffed, but I understand it's not the kid's fault, too, and I'm not so narcissistic as to think that them having my genes is so important. My anger at the mother should not reflect on the kid.
This 'random kid' stuff is absurd. The child is five or older. For all these years you have been calling it 'my son' or 'my daughter', and it has been calling you 'papa' or 'dad'. You've changed its diapers, sang it to sleep, fed it, clothed it, played with it, taught it words, hugged it after a bad dream. You are its world.
If after all that time it turns out to be not genetically yours I'm sure that hurts. Probably hurts a lot, if it's a betrayal by your partner.
But to pretend that it is in any way the same thing as the government assigning you 'a completely random child' is an absurd hyperbole. Five+ years is a decently long time to be (or think to be) someones father, but for the child that is literally its whole life.
So tell me, if it turns out after 5 years your child isn't biologically yours, you would just abandon it? It's been a nice few years but now it's over, leave to buy cigaretes and never return? And you think remaining its father is the un-manly thing to do? That sounds completely insane to me.
>my brother in Christ, people abandon their biological children all the time without anyone clutching their pearls about it
I'm pretty sure a father abndoning a child like that is one of the most taboo social nonos a human can commit I'm almost any culture? Where I am from in rural america physical vigilante violence is reserved for such types. So yes very pearl clutching
I disagree here. Blood tests done at birth are done specifically for the benefit of the child (and with minimal risk to the child). A paternity test has no benefit for the child (it doesn't tell you who the father is, simply who the father isn't) and a ~1% risk of harm to the child.
The period immediately after birth is one of the most dangerous times for children, and we (should) specifically take action to protect them in a moment where they are at risk and have no agency. A paternity test would increase the risk of harm to the child (either through violence, deprivation, or neglect). We didn't even get to the subject of possible violence against the mother either, which is likely.
Wouldn't the marginal risk from the blood test be zero, since they do a little blood prick on their foot anyway?
Also, there's a second order effect you're ignoring: a mandated paternity test would change expectant mothers' behavior leading up to the birth. You wouldn't try to dupe someone if you knew you'd be found out. Or, if you weren't sure, you'd more likely be transparent.
I did some looking, and it's so rare that there aren't any go-to statistics to cite. There are some reports of men committing murder after a paternity test, but it's unclear to me how what you're saying is anything more the speculation.
It might actually be that mandatory paternity tests reduces the background rate of familicide. All of the reports that I could find were only after the father had invested considerable time into raising the child as their own. The stakes of the deception are much higher. But if they know the day the baby is born (or earlier), then it's much easier to walk away. It also makes it pointless for the deception to happen in the first place.
The internet is truly a wild place. You can say something like "We shouldn't do mandatory paternity tests at birth because they bring no benefit to the child" and someone responds with "So you're saying we shouldn't stop wife beaters?"
No bitch, that's a whole different sentence. What the fuck are you talking about.
The essence of your comment is that paternity testing should be avoided because there is no benefit to children and there is potential harm to women. Your focus was not on the mandatory nature of any such testing.
And I believe you understand my analogy in spite of your faux confusion and outrage.
That’s not even my argument though? I was very clear that specifically immediately post birth is a high risk time and that mandatory paternity tests at birth increase those risks with little to no benefit to anyone. I did not say anything about forcing a man to raise a child. You’re deliberately misreading my point to argue against a straw man.
Are you gaslighting? Your comment is just above, you can reread it as many times as I have trying to extract any other argument with as little success.
The benefit is to the "father", obviously, in confirming paternity or alerting him of infidelity and fraud. It's either peace of mind or potentially life-changing. The benefit is incalculable.
Your only arguments for why immediately post-birth is a poor time are that it would be convenient for everyone else (including the perpetrator of the fraud) if the victim was unaware and continued to be exploited for some time (how long? when would be a convenient time for the reveal?). That is outrageous.
A stronger argument in line with the "benefit of the child" thinking would be that slight domestic violence should no longer be grounds for divorce since divorce rarely benefits the child.
Which is obviously a crazy line of thinking, but so is "let's force a man to (financially) raise a child that isn't his".
That’s not even my argument though? I was very clear that specifically immediately post birth is a high risk time and that mandatory paternity tests at birth increase those risks with little to no benefit to anyone. I did not say anything about forcing a man to raise a child.
.. you do realize a paternity test can happen with just a cotton swab? And aside from that, they already get a heel prick / blood spot test to check for a bunch of things. Drawing a tiny bit of extra blood from that in no way presents any extra danger to the baby.
Thanks, that answers my questions about how pedigrees were preprocessed for a study like this:
1. Isn’t there a very high chance any particular male’s result is true for both father and uncle?
2. For young teen mothers, sometimes a family of older mother and two assumed siblings is really grandmother, mother, child. Paternity and slightly maternity are secretly, generationally obscured. So two assumed female siblings might share less than half-sibling measures of autosomal DNA.
It's been a while and I was always a bit shaky on the actual genetics, so hopefully an actual expert can weigh in here, but as far as I remember -
For 1 it depends on the penetrance model (a score on whether all individuals with the disease allele(s) express the disease phenotype: 1=all, 0.5=some, etc.) along with whether the allele's mode of inheritance is recessive/dominant, X-linked or not, and how consanguineous/inbred the pedigree is.
If I remember it right, if a father/son combo always express the disease allele, then the pedigree is x-linked recessive. If you see an uncle/son combo, and test for it, and the linkage score for the region of interest (the likelihood that the disease travels with the ROI computed over all individuals) goes up, then it's pretty suspect.
For 2, you could see the distribution of alleles without much computation. Siblings are expected to share X%, relatives Y%, unrelated Z%. By fitting to these bands, you could already see if the distribution of alleles was suspect. We never tested for mtDNA though, I don't think there were many chipsets for it back then.
Awesome, I appreciate that. Ok so my question for the researcher would be:
1. Circumstances where both mtDNA and Y chromosome are shared between biological father and pedigreed father. I think the Biblical term is Levirate marriage.
2. Circumstances without Y where maternity is secretly disputable and paternity uncontentious. I think the researcher called this secret adoption.
At distances longer than several generations, is there noise in the measure of autosomal matches such that you cannot detect these?
I'd argue that after 5 generations your descendants only have (0.5^5) no more than 3% of your genetic material, and if there's some ambiguity to one of your founders (say who has a 50% similarity to the one stated in the pedigree) then that drops to 1% (rounding down).
1% of the human genome (3billion bp) is still 30M bases, which could easily contain 1 or 2 genes which you may have genotyped, depending on the resolution of your genotyping chip (usually 10M markers spread out over the entire genome, and usually clustered around variants/genes of interest).
So yeah, even 5 generations down these differences could be detected at the variant level. Even at 10, you could still _theoretically_ find differences.
I stress theoretically, because the chance of you having all the individuals from a pedigree genotyped at the same time using the same tech (and thus the same subset of common genotypes to compare) is slim to none.
I'd say 5 generations is a rough rule of thumb where the signal is not that much higher than the noise.
You would run the analysis and get absolute nonsense results, and then you'd swap a father for an uncle, or a mother for her daughter, and the alleles would all just suddenly line up.
We would never tell the families, and since the pedigrees were anonymized before being published there was no need to. Some secrets are just best kept buried.