I could demand a DNA test, if I valued being right about my not having been adopted over not annoying my parents/insinuating that they are liars, or over not spending money on the test. I don’t have that value ordering, so I just trust them when they tell me so (and consider my other evidence adequate support, although as I mentioned, I wouldn’t say I need it.)
If that is your point, then I don’t see what work the adoption analogy is doing.
I could demand a DNA test, if I valued being right about my not having been adopted over not annoying my parents/insinuating that they are liars, or over not spending money on the test. I don’t have that value ordering, so I just trust them when they tell me so (and consider my other evidence adequate support, although as I mentioned, I wouldn’t say I need it.)