I think it comes down to how much you trust yourself; not the other person. I know this sounds a bit strange, but think about it. Most people judge others based on their own feelings. This includes personal standards and weaknesses. That is, if I know that I'd cheat at cards, by extension I know there are definately other people who would to. The same thing applies in reverse. For example, if I know I can endure 8 hours of work a day, other people should be able to do it, too. Of course, should isn't would. Heh.

Maybe my cheese slid off my cracker.