Most people’s unintelligent behavior comes from a fear of being wrong and being called out for not knowing something.
Because of this irrational fear people will be stuck to their believes, even if they know that they are wrong. To prevent this kind of behavior you have to make the other person find your solution by them self.
This is the Socratic approach to the problem. You ask the other person questions which will lead them to find the same solution as you. With facts you can emphasize the points you want to make.
Now by actively doing this by yourself and trying to understand the points of your counterpart you’re already on the right track to being more open for other ideas and therefore more intelligent.
It is the mark of an educated mind to be able to entertain a thought without accepting it.
It’s also important to keep in mind that in arguments there are no winner and losers.
It’s not me against you, it’s you and me against the problem.
The goal of an argument is not to overpower the other person and leave them angry and frustrated but to try and understand their side of the problem and them to understand yours.
Recommended Book:
How to win Friends and Influence People