Sorry folk I lived in France too long.
They start at 3, the tiniest smidge of wine in a glass or cut with water, a slow increase over time, the education of what wine is all about over time.......and they don't have the problems the UK has. No forcing - my eldest loves her wine and is pretty knowledgeable, the younger one has no interest what so ever.
And before anybody jumps down my throat, how many have you have had babies with colic.....and what did you give them - many of you going for gripe water....well that's a smidge of ethanol - and then the old teething trick of a touch of Scotch or Drambuie.......tut, you hypocrites.
In summary, treat and educate with respect and you don't end up with the vodka-fuelled idiots we see down here on the streets of Newquay falling off cliffs or murdering each other, never mind the street cleaning that is needed each summer morning to wash the stinking cube bits away.