Is ageism harmful to Wikipedia?
Once in a while, I come right out and admit, at RFA, that I generally disapprove of non-adults being admins. Back when we had a list of RFA criteria, mine mentioned this as well. Of course, there is no one particular age at which everyone magically gets that "adult brain". And, of course, we all know people who continue to have poor judgement even after being an adult for 20 years. Being an adult is no assurance of maturity and good judgement, and being a juvenile is no assurance of lack of good judgement.
Then wouldn't it be better to focus on maturity and never mention age at all? Perhaps it would be. Maturity is what's most directly important- age just gives us a handy way of guessing how mature someone might be. However there's such bizarrely strong opposition to the idea that age should have anything to do with it, that I feel it's better to come right out and say it: kids are less responsible than adults, on average. Kids have poorer judgement than adults, on average. I don't believe there's really any reasonable way to dispute this, yet people sometimes do.
Do some people object to this because that think that having good intentions is all that matters? Probably. But I'd submit that these people just haven't been around long enough to see the kind of damage that can be done by someone with good intentions. Good intentions aren't enough- we need competence as well.
Exceptional kids do exist! Just look at so-and-so! Yes, exceptional kids do exist. So do two-headed goats and seven-foot-tall basketball players. This does not mean a reasonable person assumes that all kids are exceptional. Extraordinary claims require extraordinary evidence.
But it's terrible to judge people based on age! I think that the bottom line is, I'm unlikely to change my mind on this issue, and so are other people. In evaluating RFA candidates, getting the right answer is what we're after. So, we should use all available information to help inform our choices. If we somehow know that an editor is a young kid, this is relevant information. I think it's entirely reasonable to assume that kids will tend to act like kids, and I can't fathom how such an assumption could be remotely controversial. I suspect most of the objections come from editors who themselves are not yet adults. Does this tell us anything? I suspect a great many adults find it not at all surprising or offensive that someone would expect adulthood from people seeking a position of responsibility. I further suspect that a good deal of them keep their opinions on this matter fairly quiet, knowing it's an unpopular sentiment here.