This is a theory that I have come to doubt. I think a double is likely, but not a twin. I did want to address something that was said earlier in this post. It is not against the JW religion to give up your child, if it is for the good of the child. Usually, the children will be fostered or adopted by other JWs. However, Katherine Jackson does not strike me as the kind of woman who would give up her child. She had several and kept all the others (and don't forget, she had experienced the death of a child before Mmichael came along) , so I think if Michael had a twin, it would be public knowledge and he would have be raised by Joe and Katherine.