What criteria would you use? I've met a lot of stupid people with education from well-regarded institutions and a lot of sharp people with no education past K-12, if that. Formal education seems like a poor measure.
See the problem was not about the age specifically but rather childish behavior. So by realizing that we targeted the most obvious one( being impatient) and had great results.
So yea, making something deliberately harder to use might be just enough.