James Richardson observed that if the new religious movements had access to powerful brainwashing techniques, one would expect that they would have high growth rates, yet in fact most have not had notable success in recruiting or retaining members For this and other reasons, sociologists of religion including David Bromley and Anson Shupe consider the idea that "cults" are brainwashing American youth to be "implausible." Thomas Robbins, Massimo Introvigne, Lorne Dawson, Gordon Melton, Marc Galanter, and Saul Levine, amongst other scholars researching NRMs, have argued and established to the satisfaction of courts, relevant professional associations and scientific communities that there exists no generally accepted scientific theory, based upon methodologically sound research, that supports the concept of brainwashing.