Mark Haddon's novel, The Curious Incident of the Dog in the Night-time, is a bildungsroman about a 15-year-old boy with Asperger's who prefers dogs to humans because "dogs are faithful and they do not tell lies". Animals are a motif that represents his fear and lack of connection to people. For Christopher, the truth is paramount in helping him understand the world and people around him. Through the author's portrayal of not only Christopher but also the characters, honesty is presented as vital in building trust in relationships and in understanding people's individuality. Nonetheless, the novel also delves into the complexity of telling the truth-sometimes, honesty is difficult to achieve and may even be necessary to help people cope with difficult issues. .
As the protagonist Christopher Boone demonstrates, honesty develops trust, which is fundamental for healthy relationships. Lies hurt relationships; this is most evident in Christopher and his father's relationship. Christopher has a strong need for order and predictability. This is why he detests metaphors and fiction novels because they "are lies about things which didn't happen" and make him "feel shaky and scared". He cannot trust anything or anyone that is built on a lie; this is why honesty is crucial in helping him accept other people. The narrator mentions that "loving someone istelling them the truth." He can only have a strong relationship with his father because "Father always tells [him] the truth, which means that he loves [Christopher]." This is why Christopher feels such a strong sense of betrayal and decides to run away when he discovers his father's lies about Mother's "death". In the denouement, the relationship between the protagonist and his father remains damaged by deceit. Inevitably, without truth, it is hard to maintain trust in relationships. .
Mark Haddon's novel also shows that telling the truth in a tactful manner is essential in helping people understand each other's differences.