Yes this is true, but each one of us thinks differently and it's our differences that stand in the way. If we listen closely to those who actually do not think, they bring a value to us as humans.
Donkey's have never been thought to be intelligent, only I believe because we addressed them as Jack Ass, and kept thinking they were stupid because of the way they acted. Today they are intelligent and loyal pets.
As far as changing people's thinking. When the groups dissipate from bringing them to one belief will each person realize their are better options.