I'm not sure if this is the message you intended, but it's worth noting that having a high IQ doesn't necessarily prevent someone from being an idiot.

Historically the word "idiot" was used particularly with those with very low IQ scores but now is a pejorative term.

Within the context, we’re talking about someone who can be trusted to be mature with a firearm. That’s more true for an average Air Force servicemember than the average American. I’d reflect OP’e scepticism if we were talking about the average Army, Marine or Navy servicemember, in large part because young men are stupid and the folks in those services skew younger than the Air Force.