" The orbitofrontal cortex is the reward center of the brain. Those who exhibit reward-seeking behavior have a large orbitofrontal cortex,” someone says. “That means that Ms. Prior engages in very little reward-seeking behavior.” “Not just that.” Jeanine smiles a little. Blue light from the screens makes her cheekbones and forehead brighter but casts shadows in her eye sockets. “It does not merely indicate something about her behavior, but about her desires. She is not reward motivated. Yet she is extremely good at directing her thoughts and actions toward her goals. This explains both her tendency toward harmful-but-selfless behavior and, perhaps, her ability to wriggle out of simulations "

― Veronica Roth , The Divergent Library: Divergent; Insurgent; Allegiant; Four: The Transfer, The Initiate, The Son, and The Traitor