David Ginsburg's blog. We sometimes hear from parents who think we should "push" their kids. Or who wonder why we don't give grades. Or who believe that Montessori education is against competition and that competition is a good thing: it is the way the world works. All of these are forms of manipulation--and can work in the short run with certain children--but only until the reward is withdrawn.
And by the way, Montessori children are competitive. We just don't using grading, class ranking and rewards as a means to "motivate" (ie, manipulate) them. We don't have to. They are already motivated. Self-motivated.
Or as one of our 8th grade students said several years ago, "We motivate each other to be self-motivated."