In Divergent, nearly everyone is born into a family that belongs to one of five factions. At sixteen, each individual formally declares an allegiance to a faction. Those who live apart from the factions are known as the factionless. Individuals can be declared factionless for a number of reasons. The most common is when a novice fails to complete initiation into his or her faction of choice. This can happen at any stage of initiation. In the novel, Molly and Drew become factionless when they fail to rank in the top ten after Stage Three of the initiation process. In Chapter 6, a Dauntless candidate falls to her death as she tries to jump from the train to the roof of Dauntless headquarters. Later in the story, Edward and Myra leave Dauntless after Edward is stabbed in the eye by Peter and Drew. Being factionless means that one must live on the outskirts of society and depend on factions like Abnegation for sustenance and shelter. The factionless also perform the dirtiest jobs in the city. Many are garbage collectors, janitors, and construction workers, while others operate the trains and buses.

Roth describes a few landmarks that those familiar with present-day Chicago may recognize. In the novel, Tris enjoys zip-lining down 100 stories from the top of the Hancock Building. The present-day Hancock Building also has 100 floors and boasts a new 360 Chicago Observation Deck. Another familiar Chicago landmark in the novel is the Hub. Initiates and their families attend the Choosing Ceremony there. The novel states that the Hub was once called the Sears Tower. In present-day Chicago, the Sears Tower is known as the Willis Tower, a building with 108 floors. Yet another Chicago landmark is the Millennium: this is the park where Tris and Caleb meet during Tris's brief visit to Erudite. In the novel, the park boasts two distinctive structures: one of an abstract mammoth and another of a giant lima bean. In present-day Chicago, the lima bean structure is called the Cloud Gate (nicknamed “the Bean”); it is a stainless-steel sculpture by Anish Kapoor, a British-Indian artist.

The Abnegation faction believes that selflessness dispels conflict, envy, and vice. In Abnegation, members live a life of service to promote societal harmony. As an outward sign of their humility, they live and dress simply in gray, nondescript clothing. Many Abnegation members engage in charity work to benefit the factionless. For example, Natalie Prior (Tris's mother) sometimes delivers homemade baked goods to the factionless sector. In her spare time, she also organizes groups of workers to help the factionless with their food, shelter, and employment needs. It is important to note that Abnegation families are a diverse group: while some families are religious, others do not profess devotion to any religion.

The Erudite faction believes that true wisdom promotes understanding and peace. Intellectual aptitude is so prized that members are required to wear at least one article of blue clothing every day; the faction believes that blue releases calming chemicals that aid mental acuity. Members study subjects such as sociology, psychology, mathematics, science, communications, and history to better comprehend and interpret the world they live in. For example, psychology is an important subject because it fosters an understanding of human behavior, while communications is prized because it facilitates the perfecting of human discourse. The faction so treasures intelligence that it removes mentally deficient members from its community. Erudite claims that it does this for practical purposes and that those who cannot engage in intellectual work must find their life's purpose in menial work. The antagonist, Jeanine Matthews, belongs to the Erudite faction.