This is not true. My wife has taught in a Montessori classroom for over a decade, and the children who get the most out of it are the ones who would be labeled as "problematic" in other environments.
I went to a Montessori school in Sweden for 10years and while i never was a problem child. I have always had problems with learning things, taking long time and lack dicipline and organization. I never got the most from it, instead the school got the most of my will to do everything but learning school subjects.
I went to a montessori school for 10 years and i fail to see how a system where you except a "slow" child to want to learn subject that it find difficult and put in the time, dicipline and efforts into it. The method is all about children wanting to learn subjects that are difficult and challenging for them by them self with very little structure and minimal interferance.
Montessori originally designed her education for mentally disabled children[0]. One key aspect of her philosophy is to "let the child lead" and work with them at their own pace.
It is very much true, I am one of the children that got left behind in a montissori school. There where others like me at the school also but none as severe as me. It really only benefitted the ones who where smart from the beginning.
