What makes this interesting is that most subjects have a variable threshold. A classic example is that stealing is wrong, but stealing to feed your starving family is acceptable.
I love to test the lines of people. I ask them if they would do a particular action (like picking a fight with a chimpanzee), then I ask them more questions until they change their answer. (Would you fight a chp for a million dollars? What about ten thousand? What if the chimp picks a fight with you?)
When you test a person's lines, you may discovers the angles through which you can manipulate them, and that can be critical to moving the plot along.