I think that someone becoming a JW or remaining a JW has less to do with their intelligence and more to do with their suceptability to mind control. The longer I am away, the more I am amazed at the level of mind control used in the WT organization.
People who are well educated generally have a more secure job situation than those who aren't. Again, generally speaking.... They have likely picked a career that they enjoy, instead of being stuck in a dead end job simply to pay the bills. They feel better about themselves and their ability to make decisions for themselves. They aren't as vulnerable to the WT conversion techniques.
I know some extremely intelligent JWs, and have also wondered how on earth they can continue in this religion... There is no way they can't see the inconsistencies.... But again, I think it comes down to their inability to break free of the WT mind control techniques. Very sad.
GGG