What is Ben's attitude towards The Wave in chapters 10-12?

In Chapters 10-12, Ben Ross seems to be almost as swept away by the experiment as his students. In Chapter 10, Principal Owens warns him that things might get carried away, something Ben's wife already addressed in a previous chapter. Ross, however, sees himself as completely in control of the experiment and believes that the leader of The Wave, he can end the experiment as quickly as he started it.

It is also in this section that the students begin to act of their own.... mysterious notes appear, pamphlets and posters the Wave Rally are everywhere, and Robert approaches Ben, offering his services as Mr. Ross' bodyguard. At this point, Ross feels a bit of apprehension..... even fear, as he comes to see that he's actually lost control of the experiment.