Repetitive, purposeless behaviors are almost always a symptom of autism. In fact, many parents worry about autism when they see their child repetitively lining up toys, spinning objects, or opening and closing drawers or doors. Repetitive behaviors can also involve saying, thinking about, or asking about the same thing over and over again. In rare cases, repetitive behaviors can actually be dangerous; more often, though, they are a tool for self-calming. They can become a problem, though, when they get in the way of ordinary activities or make it tough to get through school or work.

Practitioners and researchers call repetitive, apparently purposeless behavior "stereotypy" or "perseveration," and such behaviors are actually described as symptoms of autism in the DSM-5 (the official diagnostic manual). As is clear from the wording of the diagnostic criteria, being a "creature of habit" (preferring to follow a set schedule or eat certain foods, for example) is not enough to suggest autism; rather, the behaviors must be "abnormal in intensity or focus," and changes to those behaviors must cause "extreme distress." Here is the description from the DSM:

Restricted, repetitive patterns of behavior, interests, or activities, as manifested by at least two of the following, currently or by history (examples are illustrative, not exhaustive; see text):

Stereotyped or repetitive motor movements, use of objects, or speech (e.g., simple motor stereotypes, lining up toys or flipping objects, echolalia, idiosyncratic phrases).

Insistence on sameness, inflexible adherence to routines, or ritualized patterns of verbal or nonverbal behavior (e.g., extreme distress at small changes, difficulties with transitions, rigid thinking patterns, greeting rituals, need to take the same route or eat the same food every day).

Highly restricted, fixated interests that are abnormal in intensity or focus (e.g., strong attachment to or preoccupation with unusual objects, excessively circumscribed or perseverative interests).

Repetitive behaviors in autism can vary radically from person to person. For some people, it involves saying or talking about the same things over and over again (for example, listing all of Marvel's Avengers and their powers, reciting scripts from TV, or asking the same question many times in a row). For others, it involves physical actions such as repetitive rocking, flicking, or pacing. In more severe autism, stereotyped behaviors can be violent; head-banging, for example, is a stereotyped behavior. Some people on the autism spectrum engage in repetitive behaviors constantly, while others only occasionally perseverate (get stuck in a behavioral routine) when they're stressed, anxious or upset.

Many people with autism feel very anxious when asked to change their routine or schedule. While changes can be annoying to someone who is not autistic, autistic reactions to change can be extreme. When a person with autism is asked to change a routine, for example, the response can be overwhelming anxiety or anger, even if the person is very high functioning.

Sometimes perseverative or stereotyped behaviors are obvious because they are so marked or unusual. Rocking back and forth for long periods, opening and closing doors repetitively, or reciting the same lines over and over are clearly unusual behaviors.

Often, however, autistic perseveration may not be obvious to the casual observer. A person with autism may, for example, ask "Do you like Marvel movies?" Upon hearing that the answer is "yes," the autistic person may then run through the same speech about Iron Man that he has run through ten times before, in exactly the same words, with exactly the same tone and gestures. As a parent or close friend you might know the speech backward and forward, but as a new friend, you might not even notice the repetition.

Of course, perseverative behaviors are not unique to people with autism. Most people engage in some such behaviors. Nail biting, pacing, pencil or toe tapping, compulsive cleaning, or even a "need" to watch the same TV shows or sporting events without fail are all forms of perseveration.

For some people with autism, the problem of perseveration is really no problem at all, since it only arises at the same times as it would for other people (usually under stress) and the behaviors are fairly unobtrusive. Perseveration can even be a plus for people with autism, since it may relate to a passionate interest that can lead to friendships or even careers. An individual who is perseverative in his interest in computer games, for example, can join gaming clubs where she'll find others with a similar passion.

For many people with autism, though, perseveration or repetitive behavior is not only disturbing to others but it's also a major roadblock to communication and engagement in the world. A person who compulsively flicks his hands to the exclusion of anything else is clearly unable to attend to the world around him or take part in real-world activities. And while there is nothing intrinsically wrong with talking about the same subject in the same way over and over again, such behavior can cause a variety of social and practical problems.

No one really knows what causes perseveration in people with autism, though there are a variety of theories. Depending on the theory you espouse, you are likely to select a particular treatment (or no treatment at all). Of course, if a behavior is dangerous or risky it must be changed. Some treatments have been more fully researched than others, but all have had some success with some individuals and less success with others. For example:

• If you believe perseveration is a behavioral issue, you are likely to use behavioral techniques (rewards and, in some cases, consequences) to "extinguish" the behavior.
• If you believe repetitive behaviors are a self-calming technique used to block out too much sensory input, you are likely to use sensory integration techniques to help the individual self-calm and regain a sense of control.
• If you believe perseveration is a manifestation of real interests on the part of the person with autism, you are likely to use therapeutic techniques such as Floortime or SonRise to connect with the autistic individual and help him turn perseverative actions into meaningful activities. For example, a person who lines up toy engines can often turn his repetitive actions into symbolic play, and can even build on his perseverative interest to develop social skills.
• If you believe the perseverative behavior is caused by anxiety or a chemical or neurological issue, you are likely to attempt to control the behaviors through the use of pharmacotherapy.

As a parent, you may be embarrassed or put off by your child's repetitive behaviors. Before taking action to "extinguish" them, however, it's important to understand the purpose they serve. If they are really helping your child to stay calm, manage sensory challenges, or otherwise handle the demands of daily living, you'll need to support your child as he or she modifies or expands upon his routines. That may mean finding a therapist to work with your child, or modifying your child's environment to make it less challenging.

Credit link:  https://www.verywellhealth.com/repetitive-behaviors-in-autism-260582