Within 12 hours I had two parents email me their "experiments". Here is how things went for one of those moms:
So tonight I made fish with broccoli and brussels sprouts...not a child's favorite food, for sure! My daughter instantly started complaining about the brussels sprouts and I responded with "I know." She continued on about how much she hates them & I just repeated "I know." After about 3 "I know's" she stopped and we talked about something else. She never ate her brussel sprouts, but she did stop complaining.
What a huge success! Make the effort to TRY the "I KNOW" and see how you can tune down the whining and complaining in your life by going brain dead!