Figle, it's on the FB app, and I think we've been in 4 games together total, in two we've worked together, the other there wasn't any real contact.
I don't auto ally, nor do I auto oppose, but if all other factors are equal, I'd rather ally with a good player if I'm given a choice. But I'll also stab happily if necessary. In one of the games we're currently allied, that alliance happened as my former ally stabbed me, the plan had been to take him out, instead we worked together.
Frequently, regardless of intentions, the actions of other players force an alliance regardless, it happens.