Their conversation often consists of lengthy discussions on favourite subjects. Sometimes a word or phrase is repeated over and over again in a stereotyped fashion. The child or adult may invent some words. Non-verbal aspects of communication are also affected. There may be little facial expression except with strong emotion such as anger or misery.
Gestures are limited, or else large and clumsy and inappropriate for the accompanying speech.
Comprehension of other people's expressions and gestures is poor and the person with Asperger's Syndrome may misinterpret or ignore such non-verbal signs. At times, he may earnestly gaze into another person's face searching for the meaning that eludes him. For example, children with Asperger's Syndrome develop an extreme interest in subjects such as astronomy, royalty, subways, bus timetables, or certain addresses. Some obsessions can even shade into the preoccupations and hobbies of normal children such as horror movies, wrestling, or rock videos. The difference is that this is the only activity the child participates in.