How do you measure that? IQ test scores? Degree level? Number of Degrees? Profession? Conversational skills?
You’ll find people who behave “un-intelligently” and at the same belong to high-paying professions and are highly educated.
I think he should be intelligent enough to use his knoweldge/education/experience in a constructive and ethical manner. He should be intelligent enough to consider views from various angles before reaching a decision…not base a decision solely on a “cultural” or “everybody else does it” or “that’s just how it is” view.
And not only limit his intelligence to conversation…but to put it into action. For example, having the maturity to listen to multiple views, weighing the consequences, etc.
Intelligence is as intelligence does.