Really during your life you haven’t encountered much net evidence towards either direction shifting your probability assignment away from the base rate, e.g. how much you look like your parents, whether you share some uncommon medical condition with either of them, blood type, etc.?
I have very little expertise in quantifying the effect of that evidence, and in the aggregate it doesn’t seem strong enough to make the probability negligible or large.
The strategic concerns here are also amusing to ponder. (There’s several reasons that 23andMe shows you 2nd and higher cousins with no prompting, but wants your approval before they show you first cousins.) The more one suspects being swapped at birth, the more important it is to find one’s birth family for health prediction. But, I’ve had my SNPs read, which I imagine screens off much of the benefit of knowing family history for medical conditions. It’s also less damaging to the existing family structure: most people who learn they were swapped at birth maintain their relationship with the parents that raised them, and also gain some sort of relationship with their genetic parents.
If you suspect infidelity, though, then the picture is very different. Again, learning your birth father tells you something about health, and may be a valuable social relationship (for one, they may not have any other children; in the swap case, there’s someone else in the mirror of your situation); it’s probably tremendously destructive to your current family arrangement, though.
Really during your life you haven’t encountered much net evidence towards either direction shifting your probability assignment away from the base rate, e.g. how much you look like your parents, whether you share some uncommon medical condition with either of them, blood type, etc.?
I have very little expertise in quantifying the effect of that evidence, and in the aggregate it doesn’t seem strong enough to make the probability negligible or large.
The strategic concerns here are also amusing to ponder. (There’s several reasons that 23andMe shows you 2nd and higher cousins with no prompting, but wants your approval before they show you first cousins.) The more one suspects being swapped at birth, the more important it is to find one’s birth family for health prediction. But, I’ve had my SNPs read, which I imagine screens off much of the benefit of knowing family history for medical conditions. It’s also less damaging to the existing family structure: most people who learn they were swapped at birth maintain their relationship with the parents that raised them, and also gain some sort of relationship with their genetic parents.
If you suspect infidelity, though, then the picture is very different. Again, learning your birth father tells you something about health, and may be a valuable social relationship (for one, they may not have any other children; in the swap case, there’s someone else in the mirror of your situation); it’s probably tremendously destructive to your current family arrangement, though.