Just say, "Thank you for sharing that with me" and leave the room!

You are both old enough that neither of you will have your mind changed by the other's arguments.

Remember, when you point a finger, there are 3 more pointing back at you. Dontsay that! But maybe find something more neutral you can argue about? Religion? Politics? Pronouns? Which way to roll the toilet paper? You both seem to like psychology - maybe share articles that are more informative but less pointed.