Can we go back to the assumption that kids think rationally? What kind of asinine assumption is that? Anyone who has taken a basic psychology class will know that this is categorically untrue. Children build the ability to think over many years in multiple stages during different age ranges. Children under 6 definitely aren't able to think about abstract consequences of their actions, that's why you give them a clear and direct consequence for doing something, ie. a slap, time out, etc.