College at the age of 12 I can see. Suddenly they're put in an environment where everyone is substantially older and more mature, and with nobody their own age around. That's a huge leap.

But taking a test? That's not even remotely similar. In that case, the damage comes not from a strange environment or lack of peers, but simply from a conformist attitude that comes from people saying this stuff shouldn't be done. It's self-fulfilling.

Taking that kind of test is far worse imho. (Been there, done that...) It gives the parent a warm fuzzy "our kid is a genius" feeling as they encourage their child to do so, and the feeling oozes back onto the kid as an "I am a genius" anti-social attitude. Peer rejection won't be far behind, and there's absolutely no way anyone can argue this is good for the child with a straight face.

That attitude doesn't require the test, nor does the test require the attitude.

The real problem is that "I am a genius" is seen as being automatically anti-social. "Smarter" is seen as "better" and that separates them. Ultimately it comes back to the conformist attitude I'm arguing against. That is the problem. Get rid of that, make it acceptable to be different, and passing a test won't matter.

A test makes that attitude materially more likely.

Encouraging kids to be smart and do smart things? Go for it.

Labeling them as smart? Sure, as long as you don't forget to teach them a healthy dose of humility.

Constantly labeling them as smarter? Uh oh... did I mention humility yet?

Making them pass tests to validate that they're smart? Kids don't need or want that; the parents do. It's a recipe to set their kid's life ablaze until young adulthood -- or later.

You're still assuming that "smarter" means "better" and that "better" means "separate".

What if we held the attitude that "smarter" was just another aspect of the genetic lottery, like your height or the color of your skin? What if we taught our children that it doesn't matter what you are, it matters what you do?

Why should telling a child that they're "smart" be any worse than telling them that they're "tall"?

The problem isn't labeling them as smart, the problem is the pervasive attitude that smart can be a substitute for other things like hard work or kindness, and the attitude that a child who's too smart is somehow no longer compatible with his peers.

Why shouldn't a child genius both pursue extreme mental enrichment and participate in life as a peer with other children of his own age? There's nothing that inherently separates prodigies from their peers. We make it happen.