I don't think it works that way.
I wouldn't use the word smart to describe the people (that I know) that fall for scams/conspiracy theories.
Now, you could say that they incorrectly think they're to smart, but then that means how smart you consider yourself isn't relevant, i.e. a not-smart person and a smart person both consider themselves smart.
Scams rely on two things:
1. Over-confidence. The often (but not always) target the elderly because the elderly have pride that comes with long living. When you think you've seen it all, you think you know it all.
2. Emotional irrationality. The scammer is expert at quickly putting a person in an emotionally agitated state, negating good rational thinking. This is easier to do when pride creates a blind spot to catch someone off guard.
People fall for scams not because they are stupid, but because they are humans which tend to be easy to manipulate by playing our cognitive biased and emotions against us. Scamming is both an art and an industry as a result.
Assurance makes you a sucker.