I believe in evolution but the problem with this Indigo Child thing is that evolution is
adaptive; it helps the species survive by allowing the species to fit better in its changing environment. Traits that make people want to jump up and down on you aren't likely to make you more fit to survive.
I first heard about Indigo children many years ago on a thread on the Indigo Girls (the rock group) message board once. I couldn't believe that there were people who bought into this nonsense. I'm usually pretty open minded but I have to agree with the posters who say that this is nothing more than parents looking for excuses for children who act like brats.