How we cite our quotes:
Ender leaned his head against the wall of the corridor and cried until the bus came. I am just like Peter. Take my monitor away, and I am just like Peter. (1.82)
This is one of our first impressions of Ender. He's just been fretting about how Peter will react to the removal of Ender’s monitor, and now he’s worrying that he might turn out to be just like Peter. From the very first chapter, we see that Ender is almost as scared of turning into Peter as he is about being killed by Peter.
He toyed with the idea of trying to be like the other boys. (4.17)
Most of Ender’s identity problems come from his worry that he’s a bully and a killer, like Peter. But here, Ender wonders for a moment about what it would be like to be “like the other boys.” (We guess he means to wonder what it would be like to be just a regular boy – though we should keep in mind that these “other boys” are also Battle School super-geniuses. Not exactly regular guys.) The fact that Ender only thinks about this here – this one time – shows how Ender is really much more worried about whether he’s going to turn out like Peter.
I’m a murderer even when I play. (6.120)
All of Ender’s other games are war games, so of course he’s “killing” when he plays those game. When he plays the mind game, though, he tries not to be a killer. Whoops. When he kills the giant in the mind game, this shows to him (and some of the administrators) that he’s like Peter. (Or at least like Ender’s idea of Peter.)