The voices (one of them evidently Graff) decide that Ender needs a very special sort of social balance: "With Ender, we have to strike a delicate balance. Isolate him enough that he remains creative - otherwise he'll adopt the systems here and we'll lose him. At the same time, we need to make sure he keeps a strong ability to lead." Chapter 4, pg 27 The isolation as a leader will happen, Graff says, before the ship reaches the school, so Ender will have no chance to become complacent.
On the spacecraft, we learn that Graff runs the Battle School, and he quickly lectures the launch group of twenty boys that Ender is the only one in the group with a mind worth training at school, because Ender has a mind that excels. As soon as Graff returns to his cabin, boys start picking on Ender because of Graff's work. The child behind Ender pokes him in the head repeatedly. Patiently, Ender times when the next blow would arrive, and breaks the assailant's arm. At that point, Graff returns, and reiterates his previous comments. After arrival, Graff and Ender talk, and Graff explains that Ender is not going to have any friends in the adults, just teachers. Afterwards, Graff and Major Anderson discuss Ender. " 'Anderson, think what we're going to do to him.' ... 'We're going to make him the best military commander in history.' 'And then put the fate of the world on his shoulders.'" Chapter 4, pg 36
