There is no such thing as a "conclusive" study. Not to mention the fact that he used a compilation of various other studies, at least some of which are probably biased. As much as I hate to think about experimenting on children, the only way to settle this debate would be to conduct an experiment with different treatments and control groups. Since that will probably never happen, these studies really don't do anything but make everyone throw some mud and feel angry. Also, where is any of his data? What was his methodology? Did he use a 2 proportion Z-test? If so, what was his alpha level, his null and alternative hypotheses? This is really just irresponsible statistics that seems to be aimed at getting attention rather than actually providing useful data.