> The carrying out of a paternity test outside the legal framework carries penalties ranging from one year's imprisonment to €15,000 fine.
Official source: https://www.service-public.fr/particuliers/vosdroits/F14042?...
But in practice, I expect a paternity test to come in an otherwise troubled relationship, so I don't know how often it happens that both parents would seek to get one.
What’s the gene pool loss if the kid actually isn’t his? Seems to me that that his dating pool will then expand from zero to many. A rational male may think that offering more than 18 years of his life is more significant than not offending someone once.
It's like drawing conclusions about human society based on just watching prison inmates interact.