Leviathan.Angelskiss said:
I have to disagree with the use of food as a punishment or reward, it has the potential to create very unhealthy eating patterns through out life.
You can rule out every form of punishment using that arguement. Everything has the potential to harm a child later in life.
Food is too high on the "hierarchy of needs" not to use it to your advantage. Here's an example I have given before of a Ninja mind control statement usefull when training children.
A family friend complained that he can't get his kids to clean up their rooms. They go up there but then they get distracted and start playing and never get the cleaning done. "Watch this" I tell him then peek my head in their room and shout.
"Hurry kids!!! We can't go get ice cream until after you finished cleaning your room!!!" <insert sounds of kids breaking their necks getting their room cleaned here> and if they start slowing down a simple "ice cream!" will get them to pick up the pace.
So what this statement does it implants a desire for a reward (they didn't know they wanted), a sense of urgency (that doesn't really exist), and a clear, simple goal for them to obtain the reward.
If you had instead just said something like "Hey, If you kids clean your room some time today maybe I will take you out for some ice cream later" they have time while they are cleaning to weigh the reward against the effort they are putting in and decide it's not worth it and then just quit working or worse, start negotiating...
And if you are some kind of ice cream hating nazi like angelskiss you can replace ice cream with "go to the park/lake/beach/video game or toy store etc." I guess... Do they still have putt-putt golf courses anymore?
Anyway, the important part is the element of suprise.