There is sketchy evidence of an earlier literary reference, but that seems to have been in error? That would make the entire reversed meaning a confabulation, with an attempt to push the etymology backwards from its origin in the Nineties. Wikipedia (of course) is all over the place, and (this source claims) is full of errors.
The discussion is interesting, but the tl;dr is that there's a long etymology of kin ties being referred to as 'blood,' while referring to your kin as 'water' smacks of 'found family' 90s bullshit and doesn't have a firm etymology.
Its worth noting that concepts like "blood brothers" have existed for centuries, and are common enough that boys still forge those types of ritual bonds on instinct.
So clearly the idea of it has always been somewhat around, even if not in a settled phrase.
I searched the phrase and found a discussion on the etymology which argues the origins of the phrase: https://english.stackexchange.com/questions/147902/original-meaning-of-blood-is-thicker-than-water-is-it-real.
There is sketchy evidence of an earlier literary reference, but that seems to have been in error? That would make the entire reversed meaning a confabulation, with an attempt to push the etymology backwards from its origin in the Nineties. Wikipedia (of course) is all over the place, and (this source claims) is full of errors.
The discussion is interesting, but the tl;dr is that there's a long etymology of kin ties being referred to as 'blood,' while referring to your kin as 'water' smacks of 'found family' 90s bullshit and doesn't have a firm etymology.
Its worth noting that concepts like "blood brothers" have existed for centuries, and are common enough that boys still forge those types of ritual bonds on instinct.
So clearly the idea of it has always been somewhat around, even if not in a settled phrase.