Christopher’s defining characteristic is his inability to imagine the thoughts and feelings of other people. In other words, he cannot empathize. Because he cannot imagine what another person is thinking, he cannot tell when a person speaks sarcastically, or determine a person’s mood by his facial expression. This inability to empathize is one of the most prominent features of autism-related disorders, and this characteristic as well as a few others—Christopher’s difficulty understanding metaphors, his fixation on certain topics, and his computer-like ability with numbers—strongly suggest that Christopher has a mild form of autism. This condition has made him extraordinarily gifted in math and science but severely underequipped socially, leading Christopher to frequently misunderstand other people, especially his father. As a result, he greatly dislikes social interaction and avoids it when possible.
Although Christopher does not mention autism by name anywhere in the novel, we see that he recognizes the ways he differs from most people and feels keenly aware of these differences. He says, for instance, that although most people enjoy chatting, he hates it because he finds it pointless. He doesn’t see social interaction as an end in itself, thus talking to another person about an unimportant topic serves no purpose. He lives as an outsider as a result. He has very few friends and doesn’t trust other people. He feels content to read in his room by himself, and he even fantasizes about being the only person alive on the planet. Christopher also recognizes and takes pride in the strengths that result from his condition, such as his talent for math and his remarkably accurate memory. His memory allows him to recall an entire event in extraordinary detail, and he uses it to navigate social interactions by memorizing a chart of facial expressions and the emotions associated with them.
Christopher shows a growing desire for independence throughout the novel, and through much of the novel we watch as Christopher gains the confidence to assert himself. He shows his yearning for independence in a few ways, rebelling against his father by disobeying his orders, for instance, and fantasizing about doing whatever he likes and taking care of himself in his recurring dream of being one of the few people left on Earth. He also begins planning to go to college, and to live on his own there. As Christopher overcomes the various trials he faces, he gains confidence in his abilities and gradually becomes more self-sufficient. This process culminates in a difficult journey to London that Christopher undertakes by himself, a feat that represents a significant triumph for him since he has never traveled by himself. At the end of the novel, Christopher feels he has overcome his challenges, and he feels ready to be on his own.
Christopher’s father often goes to extremes when demonstrating his emotions, occasionally blowing up in anger, and he lacks the confidence to work through his problems verbally. When trying to explain himself he stutters and stops and often has trouble connecting sentences. Like Christopher, he has very few friends—Rhodri is the only one the novel mentions. He also feels emotionally devastated by the way his relationship with his wife (Christopher’s mother) ended two years earlier, and because he has no one to help him cope with his emotions, he bottles them up until he explodes in anger during stressful situations.
Christopher’s father lovingly and diligently cares for Christopher, yet he also struggles with the frustration he feels as a result of not always being able to understand Christopher’s behavior. He carefully prepares all of Christopher’s meals according to Christopher’s rigid list of likes and dislikes, but he also becomes angry with Christopher when Christopher misunderstands him. Notably, he is extremely protective of Christopher. This impulse to protect Christopher and his desire to punish Christopher’s mother for the way she left leads him to lie to Christopher about mother’s leaving. As Christopher discovers more and more of the truth about his mother, Christopher’s father can see his relationship with Christopher deteriorating. Christopher’s father must work to regain Christopher’s trust, and the novel’s final chapters focus on his efforts to reestablish a relationship with Christopher.
For the majority of the novel, our only view of Christopher’s mother comes through Christopher’s memories. He remembers her as loving but impatient, and prone to breakdowns in the face of his tantrums. She also comes across as a dreamer who is unable to cope with the harsh realities of Christopher’s condition. But she receives a momentary turn as the narrator—the only instance in the novel when see a first-person point of view other than Christopher’s—when Christopher includes in his book a series of her letters in full. In these letters, she exhibits the patience that she lacked in her face-to-face interactions with him, writing forty-three letters over the course of two years, despite getting no response. Although she tells Christopher in the letters that she left him and his father because she thought they would be happier without her, this explanation is clearly only part of her reasoning. We also see in the letters the intense frustration she felt with Christopher and her inability to deal with his behavior, as when Christopher threw a tantrum in a department store while he and his mother were Christmas shopping. She felt unable to cope with these fits of Christopher’s, possibly because of her depression, which Christopher mentions at one point in passing. When we finally meet her in person, however, Christopher’s mother turns out to be strong-willed and independent. Even so, she evidently still finds dealing with Christopher extremely difficult because of his rigid needs and sometimes inappropriate behavior. She clearly loves Christopher but also has doubts about her ability to take care of him.