What are some examples in which readers see the negative changes in Charlie Gordon as the story of Flowers for Algernon continues?
In this fascinating novel it is shown that Charlie's meteoric rise in intelligence is not accompanied necessarily by the maturity, wisdom and understanding that we would associate with such a ferocious intelligence. One important pivotal moment is when Charlie goes to Chicago and realises that the doctors that were responsible for his experiment, and which he looked up to as if they were almost god-like figures, are actually less intelligent than him. He can't comprehend that figures that had such power and authority over him before are actually more limited than he is intellectually, and as a result, he judges them incredibly harshly:
I couldn't stay at the party. I slipped away to walk and think this out. Frauds--both of them. They had pretended to be geniuses. But they were just ordinary men working blindly, pretending to be able to bring light into the darkness. Why is it that everyone lies? No one I know is what he appears to be.
Charlie is thus shown to be actually very limited, in spite of his massively high IQ, because of his lack of understanding of himself and others. It is this event of course that leads to his escape with Algernon.