Curiosity is not a guarantee of intelligence, but a lack of curiosity is the opposite. Curiosity is far easier to probe in smalltalk and interviews without self awareness filters.
Ask questions. Either people will or won’t engage but if you have any credibility with them, they have a little bit of buy in to listen to your shit. Then you just might get them curious.
Just the other day I was walking through our local VA campus and I was curious about why every roof of the buildings built in the 1920s has a bunch of little house looking vent things on the top. I think I know the answer but I’m still curious about it.
Probably not a good example of something to spark curiosity with, but you never know what will.