Do gravitational fields produce their own gravity?
Yes. A gravitational field contains energy just like electromagnetic fields do. This energy also produces its own gravity, and this means that unlike all other fields, gravity can interact with itself and is not ‘neutral’. The energy locked up in the gravitational field of the earth is about equal to the mass of Mount Everest, so that for most applications, you do not have to worry about this ‘self-interaction’ of gravity when you calculate how other bodies move in the earth’s gravitational field.