Compare the way that Ender treats Bean to the way that Graff treats Ender. What does this say about the role of leadership or authority?

Ender treats Bean the exact same way in which Graff treats him. He singles Bean out because of his obvious capabilities and causes the others to resent him. In fact, we hear Ender's thoughts, which confirm this very concept, "Why am I doing this... Just because they did it to me, why am I doing it to him?"

None-the-less, there are also differences. Ender and Bean soon forge a relationship based on trust. Ender confides in bean because its necessary. Graff is never that straight forward with Ender...... ever. Ender also utilizes Bean's strengths; he puts Bean in charge of a special unit, he understands that Bean is just as smart as he is, and through Bean, Ender is able to gain a more extensive perspective.

As an authority figure, Ender is empathetic (we know Graff is not).