Individuals with ASD are often seen to engage in repetitive stereotyped activities. These activities may be simple or complex. Children of higher levels of ability usually show more complex routines.

Simple stereotyped activities

Examples include: flicking fingers, objects, pieces of string, etc; spinning objects or staring at objects that spin; tapping and scratching on surfaces; inspecting, walking along and tracing lines and angles; feeling special textures, cloths, etc; rocking, especially standing up and jumping from back foot to front foot; tapping, scratching or manipulating other parts of the body; repetitive head banging or self-injury; teeth grinding; repetitive grunting, screaming or making of other noises.

Complex stereotyped activities involving objects

Examples include: intense attachment to particular objects for no apparent reason; a fascination with regular repeated patterns of objects, sounds, etc.; repetitively arranging objects in lines or patterns; the collection of large numbers of particular objects, such as plastic bottles, pebbles, or the tops of Smarties tubes, for no apparent purpose.

Complex stereotyped activities involving routines

Examples include: insistence on following the identical route to certain places; insistence on carrying out a lengthy bedtime ritual; repetition of a sequence of odd body movements.

Complex verbal or abstract repetitive activities

Examples include: fascination with certain topics, eg. astronomy, birds, train time-tables, even specific persons; asking the same series of questions and demanding standard answers.

The above are just some examples of stereotyped activities. There are numerous other variations of the behaviours, which fall under the above categories.