David is introduced to the reader as a young boy. The narrative quickly moves him into early teenage years. He is the son of a very powerful man in the Waknuk society, so David is immediately respected a bit more than other teenagers. David is portrayed as trustworthy throughout the story. The best early example of this is the fact that he kept Sophie's secret of having six toes. According to Waknuk rules, David should have reported that genetic variation, and Sophie should have been banished, killed, or sterilized.
The fact that he kept the secret shows an early change in David's overall character. He shifts from being a boy that adheres to the rules with basically no questions asked, to being a rebel leader of sorts for the Deviant telepaths. A reason for his transformation is tied to a key character trait of his. David is a protective person. He protects his friends. He protects Sophie, and he frequently must protect his younger sister, Petra.
The next day I tried to send thought-shapes to Petra. It seemed to me important for her to know as soon as possible that she must not give herself away. I tried hard, but I could make no contact with her.