I'm just recalling. I've lived in a number of Central American countries. They would have two ballot boxes with the same ballots but different coloured paper for under 18 and over 18. Families would go and vote, and from whatever age you could hold a pencil you would vote in the youth election, with the same candidates, the same parties. On election night they would release the results first of what young people in the country had said, and it had an incredible predictability rate for the next election. They didn't vote the same as their parents, but they predicted the next election.
There's some insinuation that it would just be one more vote for that family, for the parents. I've turned my mind very much to this. Rather than being influenced, I think those young people would be influential. If they're in class, and as part of their class they are studying the parties, meeting the candidates, going through the platforms, they're bringing that home and perhaps challenging the voting patterns of their parents or guardians when they say what they learned today about party X's policy on the environment, which they care about, or rights on such-and-such.