The body language of autistics can be difficult for neurotypicals to understand. Facial expressions, movements, and gestures may be easily understood by some other autistics, but do not match those used by neurotypicals. Also, their tone of voice has a much more subtle inflection in reflecting their feelings, and the neurotypical auditory system often cannot sense the fluctuations. What seems to NTs like a high-pitched, sing-song, or flat, robot-like voice is common. Some children with relatively good language skills speak like little adults, rather than utilizing the immature "kid-speak" that is common in their neurotypical peers.
Since neurotypicals are often unfamiliar with the autistic body language, and since autistic natural language may not tend towards speech, autistic people often struggle to let others know what they need. As anybody might do in such a situation, they may scream in frustration or resort to grabbing what they want. While waiting for neurotypicals to learn to communicate with them, autistics do whatever they can to get through to them. Communication difficulties may contribute to autistic people becoming anxious or depressed.
Repetitive behaviors:
Although autistics usually appear physically normal and have good muscle
control, unusual repetitive motions, known as self-stimulation or "stimming,"
may set them apart. These behaviors might be extreme and highly apparent
or more subtle. Some children and older individuals spend a lot of time
repeatedly flapping their arms or wiggling their toes, others suddenly
freeze in position.
As children, they might spend hours lining up their cars and trains in a certain way, rather than using them for pretend play. If someone accidentally moves one of these toys, the child may be tremendously upset. Autistic children often need, and demand, absolute consistency in their environment. A slight change in any routine—in mealtimes, dressing, taking a bath, or going to school at a certain time and by the same route—can be extremely disturbing.
Repetitive behavior sometimes takes the form of a persistent, intense preoccupation. For example, the child might be obsessed with learning all about vacuum cleaners, train schedules, or lighthouses. Often they show great interest in numbers, symbols, or science topics.
