Part of Ted's maturation in The London Eye Mystery rests in him being able to better understand human nature. Ted's condition enables him to see the world in a very literal manner. Loose interpretations of language such as idiomatic expressions ("raining cats and dogs") and flexibility with the truth are aspects of human interaction that Ted does not understand. Part of his growth and development as a character is learning that there are times in human interaction where half- lies must be told. They are not full acts of deception, but rather are ways of recognizing that which is important in the act of telling a lie.
One example is when Ted has to lie in talking about how his sister's hair looks. He realizes that Kat places much importance on her hair. In telling the truth, that she resembles "a sheepdog" that cannot bark, not much is gained. Ted comes to realize that the lie of saying that she "looks fine" goes far in helping another human being feel good about that which is important to them. The ability to assess importance and relevance is a significant reason why Ted lies. He understands that the only way to help generate clues and leads as to Salim's disappearance might have to be to lie. Faith's rule that the kids are forbidden to find out the truth by investigating leads is something that they cannot honor. Thus, Ted lies in order to act on something more important. In this case, the law denies justice, and Ted lies in accordance to this higher end. For example, when Kat has a lead to follow, she leaves and tells Ted to lie for her. He does and says that Kat is looking for his compass so that she can investigate the lead on Salim's disappearance. Another similar example is when Ted wishes to follow a lead and with Kat already gone, he lies in writing in a note that both of them are going swimming. These are lies, half- lies at that, that Ted weaves.
Ted's maturation is shown in telling these lies, or half- lies.. He understands what the truth is and recognizes where it is. His half- lies are ways in which his growth is shown. They also reflect Ted's understanding that while truth is important, in the desire to accomplish an end product that preserves one's responsibility maintaining the social order, a lie might have to be told. Ted does not enjoy having to do so. Yet, he recognizes his responsibility for doing so. In this lesson, Ted shows maturation and growth, elements that explain the significance behind his telling half- lies.