Interesting question ...
I served in two congregations in the 20ish years I was an elder. In both I was the only one that had more than a high school education (I have a B.A. in Education which I attained ironically enough during the last few years I was an elder. The critical thinking skills I learned while getting a degree were part of what led me to leave). But this thread's question wasn't about education per se, it was about intelligence.
I believe many of the men I served with were intelligent, some highly so, but none were educated. They swallowed down the WT's party line hook-line-and-sinker and were company men all the way. So was I for most of my tenure.
Nevertheless there were two men I served with that had not even graduated high school. I often wondered if their limited intellectual ability was a result of their lack of education or if they couldn't finish high school because they just weren't smart enough. I could never really figure it out as it was a real chicken-or-the-egg sort of conundrum.
Nevertheless, they were two of the most genuinely kind, loving men I've ever known. They were also two of the most indoctrinated. Their limited education combined with their limited native intelligence often allowed them to arrive at quite ridiculous conclusions on matters. As a result, they too were company men through and through.
Even those with the most intellectual potential will never achieve all that they could as long as they remain faithful to the dictates of the WT "theology" and its associated rules, regulations, policies and practices. They are all designed to inhibit independent thought and creativity.
It is what it is and they have made it so.
00DAD