I've seen quite a bit, including Pastors and those who are selected to lead a group, fellowship, Bible Study, when they lead, they lead with a hidden attitude of "Leaders are better, therefore I must be humble".
This kind of error in logic is the beginning of virtually untraceable problems to come.
Instead, if become leader, one must first know himself already if he's really called for this post by the Lord and not by people around him in the first place. So that he is sure of what gifts God requires of him.
As for humility, that is the ever learning process for everyone, in every area. There is no causality between these two.