Sure, it's possible (even probable!) there are any number of things affecting IQ. I'm just pointing out that if you'd plotted raw IQ levels versus time, the gr

Sure, it's possible (even probable!) there are any number of things affecting IQ. I'm just pointing out that if you'd plotted raw IQ levels versus time, the graph would have the opposite sign from what you'd expect from Drum's lead hypothesis. There may be an explanation that makes it all fit together, but it somehow needs to be addressed, not just ignored or hand-waved away.