How does David change from the beginning of the novel to the end?

David believes that The Wave will help the football team cooperate with each other instead of only trying to advance themselves in the school's athletic hierarchy. He grows angry with Laurie because she disagrees with the way he embraces the movement, as well as the way he refuses to consider her feelings. In the end, David comes to see the negative aspects of the experiment, as well as the positive, and he joins Laurie in her attempts to end the project before it goes any further.