the Mythconceptions/Mythbusters about whether all babies are born with blue eyes (and the discovery that over 60% are in fact not). The article wonders how this cultural myth began and still carries force when the evidence is so against it.
I find myself thinking: cats. Specifically, cute appealing cuddly kittens. I know from time spent on Facebook Reels (truly an entire warren of rabbit holes) which I'm never going to get back. There are a lot of people out there, including people I might think are otherwise rational, who simply cannot make a distinction between actual human babies, and pets. To people who think this way, kittens are "fur-babies", our "fur-children", I am their mummy, and other pets in the house, even those of other species, are their brothers and sisters.
Kittens tend to be born with startlingly blue eyes, which later on settle down as other colours.
So is it possible that the idea of human babies being born blue-eyed and this then settling down as grey or brown or whatever, is down to leakage from observation with cats, via people who think in terms of "fur babies"? People who observe cats with more attention, interest, and absorbed devotion than they might apply to mere human infants....