I don’t believe this for a second.
This flies directly in the face of the Dunning-Kruger effect, which suggests that the surer you are, the less you know.
Now, I agree that it’s a problem when smart becomes a synonym for knowledgeable.
Anyone can spout facts, and everyone can spout horse hockey that sounds like facts.
But neither is a measure of candlepower or processing speed.
In 45-plus years of thinking about this, my take is that really bright people ask questions all the time. They only use big words when there’s no smaller word available, or when they’re nervous and fumbling. (And likely to find ‘onerous’ when they should be saying ‘pain in the ass’ …)
And I like to think really bright people are compulsive learners, because I’m a compulsive learner, and I hope that means I’m really bright and not just some old fat broad with another weird addiction. 😜