TIL people with allergies are narcissists. Checks out.
Ok, more serious response now:
I think how a person treats cats/pets can be an indication of how they treat others. Similar to watching how a date treats people working in restaurant and hospitality industries.
Even if a person dislikes cats, I expect them to not be assholes about it. Don't pick on the cat. Don't monologue on how awful they are. Realize their world doesn't revolve around you and be ok with that.