The Illusion of Choice and a "Helpful" Lesson on Parenting
If you are trying to convince your children to go to bed, do not simply say, "Go to bed," nor ask, "Would you please go to bed now?" In your child's mind, this statement can be met with one of two chioces - to obey or to disobey. If instead you ask, "Would you like to go to bed at 8 or at 9?" you have limited the scope of choices down to two, while still making it appear as if you are now allowing more choices.
While this may seem so simplistic that only children could be thus duped, there are many other examples in adult life - Coke or Pepsi? Democrat or Republican? Communist or capitalist? Monetarism or Keynesianism? War or Peace?
There are many more choices outside of going to sleep at 8 or 9, but your kids don't have to know that ;-)