“You can’t be serious!”
I’m pretty sure that this thought has crossed your mind more than once in meetings when someone you considered smart supported a (seemingly) nonsensical take.
Or when someone made an insane statement that seemed to contradict everything you consider common sense.
When this happens, instead of asking what’s wrong with them, I suggest to ask “What’s going on?”. For example, that person might
→ want to be seen by someone in the meeting.
→ want to belong to a certain (sub)group.
→ feel the need to negotiate their status with someone.
Things like that are sometimes not obvious if you’re deep down in the factual argument. But opening your eyes for it can help make sense of their take.
Once you see it, you’ll recognize that more rational arguments from your side won’t change their mind, if only because their take is not about logic at all (to be fair, it could be totally subconscious).
You’ll much rather need to find words that address the actual game they’re playing.
Which might mean asking more questions (as opposed to providing more facts). Or it might mean to ignore their take and turn your attention to the person that’s influencing the “irrational” take.
How do you handle seemingly irrational behavior in meetings?