Will bribing children permanently harm them?

Personally, I believe bribing should only be done once in a while. If you do it often, your children might get the idea that, "Oh, if I go to bed, I'll get a prize! But I don't feel like having a prize right now, so I won't go to bed!" I work in a learning center and a strategy that I've used on the children (and it works most of the time) is to ask them questions like, "Do you like getting in trouble? No. Do you like making me upset? No. You know what you can do to stay out of trouble and make me happy?" It really makes them think about their actions. Children, whether it seems like it or not, love to please adults. If you let them know (actually telling them) that what they are doing makes you upset or sad, they might reconsider what they are doing and decide they will do something that makes you happy, which, in your case, would be going to bed.