Identity serves as the most important factor that many literally live and die by in Among the Impostors. Nearly every major character in the book has at least two identities that often work against one another, highlighting the duplicity within the society. One identity is usually kept hidden, creating conflicts for the characters and with others, as they must be careful not to reveal their alternate identity to the wrong people. Luke Garner struggles to accept his new identity as Lee Grant because they are different people. Luke is an illegal third child who grew up modestly on a farm, while Lee was legal and grew up wealthy in the city. Luke feels that by pretending to be Lee, he is unable to be true to himself and internalizes society’s view of him as an impostor. Mr. Hendricks tells Luke that his “father—the father listed on your school records—is a very important man,” meaning Lee Grant’s father. In maintaining his own identity, Luke forcefully responds that he’s not his father, “And I’m not Lee Grant” (166). Luke also discovers that the notes in his files as Lee Grant have all been faked, revealing another level of deception. Luke’s difficult and gradual acceptance of both identities is indicated through his desire to ultimately have the other boys call him “L” (172).

Several other characters must contend with their identities. Many of the boys at the school are third children and, like Luke, are living by another name. A few of them reveal their real names, but others, like Trey and Luke, refuse. Some “go by three or four different names” and others “just [go] by initials” (110). When some of the boys give a new set of fake names to the Population Police, and they’re confirmed by. Mr. Dirk, Luke remembers that no identity can be fully trusted.

Some of the characters with multiple identities use multiple identities to further their own agendas. Mr. Talbot works for the Population Police, but he also tries to save third children. Although he is working to enforce the Population Law, he is “double-crossing his own employer” (6). He uses his position of authority to influence certain situations, including Luke’s enrollment and Jason’s arrest. However, his deception is designed to help people, in direct contrast to the duplicity shown by Jason. Jason’s multiple identities are used for malicious intent. He assumes the identity of Scott Renault, as well as a third child whose name is Jason. In one of the book’s major twists, he is revealed to be a member of the Population Police. Mr. Hendricks informs Luke that Jason and Nina “had never been hidden children. They were just plants. Impostors” (167). Luke once considered himself an impostor, but the term ends up being associated with Jason, reinforcing the rampant duplicity throughout the novel.

Among the Impostors constantly conveys the struggle between liberation and oppression. The conflict is best represented through the contrast between the maze-like, windowless school and the nearby woods. Inside the school, the boys are disciplined and forced to follow a strict routine. They are not allowed outside and many of them seem fearful and distraught, including Luke in his first weeks. They are served inedible food and treated like cattle, herded from class to class under the watchful eyes of hall monitors. The repressive environment of the school reflects the oppression many of the boys feel, whether because they are third children or because of other issues. Luke spends his time in the school longing for a world where he doesn’t have to pretend to be someone else.

By contrast, the woods provide open space and fresh air. They provide a new world of opportunity and possibility for Luke. In the woods, Luke finds his voice, his courage, and the road to a life that at least has some possibility for change. Through his experiences in the woods, Luke comes closer to achieving personal liberation. He is still trapped in a society that hunts and kills third children, but he takes ownership of his garden and is proud of his achievements.