Dr. Cook's Bitless Bridle

I've found the best information about bitless bridles on Dr. Cook's website. His is the only resource that has serious research behind his claims - everyone else seems to base their claims on opinion only.

http://www.bitlessbridle.com/cat/FAQ.html

In some ways you are right, but horses don't read. They know what they like and don't like. Loads of horses go brilliantly in Dr Cooks and loads don't, so I hear. Certainly I believe bits affect a horses facial nerves and breathing.
Also what about things like bosals that have been in use for hundreds of years? Who will pay for scientific research into them when, hey, they work anyway?
In the end, it's the monkey on the other end of the reins that causes ANY problems with bridles - after all, if it was left to the horse he wouldn't be wearing one at all.