Yes! The only new "convert" in my congregation has clear mental deficiencies. A very kind woman, but I don't have to be a MD to know that she has some definite imbalances going on.
even this weekend I was helping my parents (who have resumed their relationship with me despite being DFd - yay!) clean out and we came across some old WT books. I tried planting a seed by saying "we can throw these away because the doctrine has changed so much. These probably aren't even what we believe any more." My mom ignores that comment but did say "those books were deep. It's all pretty frilly now. I think it's too appeal to everyone coming into the organization and I don't think everyone coming in can handle critical thinking topics." Even the people still "in" know that the society has to appeal to a populous with lower intellect!