I decided to do a search of the Watchtower Library CD on the phrase 'independent thinking'. Only three times is it ever spoken of as being a good thing. And those three instances are quite telling about the insidiousness of all of the other times that JW publications consider independent thinking to be such a bad thing.
*** w57 8/1 p. 469 par. 7 Will You Get to Live on Earth Forever? ***
Independent thinking is difficult, unpopular and even suspect. Thought conformity is the order of our day. To seek solitude for meditation is frowned upon as antisocial and neurotic.
*** w58 8/1 p. 460 Dawns a New Era for the Irish ***
To ask a sound religious question is a demonstration of lack of faith in God and the church, according to the clergy. As a result, the Irish people do very little independent thinking. They are victims of the clergy and fear.
*** w72 3/15 p. 170 The Delight of Jehovah Will Succeed ***
Man possesses a mind and a heart, not controlled automatically by instinct, but capable of independent thinking and reasoning, making plans and decisions, exercising a free will, building up strong desires and motivation. That is why you are capable of exercising the fine qualities of love and loyalty, of devotion and integrity.
All of the other times it is mentioned, it is claimed that independent thiniking is "dangerous", and even "demonic" and "Satanic". Sounds a bit like control to me. And I think the writer of the 1958 Watchtower quoted above would have to agree.