I can try and explain it. The definition is not going to rely on any kind of hard values or studies, because it is a soft cultural term used for name calling.

I can try and explain it. The definition is not going to rely on any kind of hard values or studies, because it is a soft cultural term used for name calling. Passions that are seen as childish usually tend to lack any sort of practical utility. Action figures and games are ultimately just timewasters. Kids learning to build stuff with woodworking tools would seem less childish because that is a useful skill compared to building things out of legos. Often, a skill that would otherwise be practical becomes childish when it is simplified to be impractical, and thus, easier for kids to learn. Even in the world of fiction and literature, which can easily be argued to be a timewaster regardless of quality, the stuff that is childish is also generally seen as overly simplified. Explicitly this is done by ratings boards that don't let certain content be present in kid's movies and books. Implicitly, writers and directors can and do simplify and dumb down their work when creating something made for children. It is possible for someone making a work for children not to rely so much on simplification, but the reality is that this happens far less often then proponents of the "Young Adult" genre would suggest. Just go look at the shit you find in a bookstore if you think I'm wrong. I wouldn't call being anti-intellectual childish by this definition, though, because there is a practical value in realizing that intellectuals can say incorrect things at any time.