Bruno is the son of a Nazi commandant in The Boy in the Striped Pajamas. He has a very regulated upbringing. He knows that certain things are "out of bounds at all times and no exceptions" which is the title of chapter 5, but that does not stop him (in chapter 5) from voicing his objections when he thinks that things have gone too far; the family is uprooted from its beloved home in Berlin and sent to a place that can only be described as "desolate" (chapter 2). Bruno bravely confronts his father which is something he would never have done in Berlin. Previously, and in Berlin, he had mainly been in his father's office when he had been naughty so this behavior reveals Bruno's changing nature. He even surprises himself when he bursts out "I don't want to accept it" when Father tells him that "Out-With" is Bruno's new home. The fact that Bruno leaves his father's office "unsatisfied" further indicates that he will no longer accept matters blindly.
In chapter 6, Bruno has a discussion with Maria, the maid. Ordinarily, it is not something he would need to do but his circumstances dictate it because there is no-one else his own age to talk to, except Gretel who is "a hopeless case." Bruno even shocks Maria when he says "Stupid Father." He is becoming more discerning of fairness, noting that the rules that apply to children "never seemed to apply to grown-ups." Bruno also changes in his view of his mother when she takes "credit for something she hadn't done" (ch 7) after Pavel tends to Bruno's injured knee.
After Bruno befriends Shmuel, he becomes more accepting of the situation. Meeting with Shmuel every afternoon begins to make up for having to live in "Out-With." However, after Lietenant Kotler abuses Pavel for dropping a bottle of wine (chapter 13), Bruno wonders why his father did not stop him. Bruno begins to understand that it may be safer to "cause no chaos at all." It is significant that the only thing he can remember about his "old life" and his friends is that one of his friends is a "ginger," a physical characteristic which would not been significant previously but which now seems to be the only relevant and noticeable thing. He is changing in his perceptions of what others consider important and categorizing people on the grounds of their appearance much like the Jews are categorized by the star on their clothing, reveals that he is being influenced by his surroundings.
Bruno is also becoming less self-absorbed. In chapter 14, when he is talking to Gretel about his "imaginary friend," he begins to realize how difficult it must be for Shmuel whose grandfather is missing. Although Bruno never fully understands the implications of life at "Out-With" he does change and develop due to his experiences. Ultimately, Bruno is a model friend to Shmuel as he supports him during their last moments.