Through analyzing Christopher from Mark Haddon’s The Curious Incident of the Dog in the Nighttime and Lennie from John Steinbeck’s Of Mice and Men, it is understood that their mental disabilities lead them to social isolation. While Christopher is able to break out of his isolation through his development of becoming a round character, Lennie's immaturity hinders him.

Christopher and Lennie are characters whose dependency and immaturity shape their isolation. School is a place where one can interact with friends, but Christopher has no friends at school, and the closest he gets to any person is his teacher Siobhan. Initially, Christopher talks in a childish tone, demonstrated by his use of short and choppy sentences that make him sound immature: “The dog was dead. There was a garden fork sticking out the dog” (Haddon 1). Instead of phrasing it as “the dog was dead and it had a garden fork sticking out of it,” Haddon intentionally crafts Christopher in this way to make him seem younger. Although Lennie is older than Christopher and does not go to school, he needs someone to constantly guide him because of his mental disability that makes him act immature. Everyone on the ranch, including George, thinks that Lennie continuously causes trouble, but George is the only one who guides him and tries to get him out of it. Lennie is like a toddler who wants something really badly and continues on begging their parents; in Lennie’s case, his guardian is supposedly George. He “like[s] beans with ketchup” (Steinbeck 8), but regardless of the fact that George says that they do not have any, Lennie repeats “I like ‘em with ketchup” (Steinbeck 10) like children would when when they are not getting what they want.

Although this seclusion has an impact on how other characters view Christopher and Lennie, Christopher is able to become independent and solve a mystery, while Lennie remains dependent and continues to get in trouble, and thus is statically childish. Christopher is able to use his disability to his advantage; his mind is so complex that he is able to figure out puzzles in short amounts of time, leading him to break out of his isolation and change. Haddon uses several techniques to portray Christopher’s brain and thought process to the readers. He writes with prime numbers as chapter numbers to portray Christopher’s concrete and straightforward thought process. Since prime numbers are only divisible by themselves and one, they demonstrate clarity with a limited number of options rather than a vast spectrum of choices. In order to function and comprehend material and solve or even attempt problems, Christopher needs limited choices and decisive answers. Christopher spends many days trying find out who killed Wellington because he knows there is for sure on person in his neighborhood who did it. Throughout his journey, he matures mentally to the extent where he goes to London by himself. When he concludes that his father killed Wellington, and further deciphers the rest of the story, he finds out that his mother is alive and she has been sending him letters from London (Haddon 118). He is able to determine the whole story and figure out both sides to the problem. In Of Mice and Men, George has to repeatedly tell Lennie to stay quiet, and he has to have a backup plan because there is a high probability that Lennie will forget and mess something up. George has to repeatedly reinforce to Lennie that he has to remember whatever is told to him to make sure that there is no trouble. He asks,“What are you gonna say tomorrow when the boss asks you questions?” (Steinbeck 15). Lennie replies, “I...I ain’t gonna...say a word” (Steinbeck 15). George has a plan to hide if Lennie gets in trouble: “Lennie--if you jus’ happen to get in trouble like you always done before, I want you to come right here an’ hide in the brush...till I come for you. Can you remember that?” (Steinbeck 15). Steinbeck repeatedly foreshadows obvious incidents that will occur with Lennie to reveal how flat his character is. Readers uncover a pattern: when something with a soft texture appears in the story or when Lennie is asked to remember something, we know that Lennie is going to get in trouble. He acts like a child throughout the novel, from petting a smooth dress and scaring a girl to petting mice and ending up killing them. Because Lennie cannot remember anything told to him, he is never able to mature.

Christopher’s disability gives him the power to investigate problems and solve puzzles, whereas Lennie’s mental disability makes him cause trouble to remain immature due to his static character. Two individuals can start off at the same place, but the amount of effort put in by one person and relevant circumstances can alter the outcome. In this case, Christopher and Lennie began their journey in the same position, a boy and a man who were socially isolated, but Christopher had a goal of solving the mystery of his mother that was driving him to work hard, and because his disability had an advantageous aspect to it, he was able to achieve a lot more success than Lennie.