Marina Sarris

Date Published: December 12, 2024

A 9-month-old baby stared at a toy from the corner of his eyes, examining it from an odd angle. He was among 150 babies who took part in a research study looking for the earliest signs of autism.

The researchers found that babies who stared at objects in unusual ways, such as with repeated squinting, blinking, or looking sideways, were more likely to have autism than babies who did not.¹

As they become toddlers, children on the autism spectrum develop more obvious differences than an unusual way of looking at toys. They often begin flapping their hands, rocking, walking on their toes, banging their head, lining up toys in precise ways, or insisting that routines stay the same.

Psychologists call these repetitive and restricted behaviors, and they make up one of the two main traits of autism.

In recent years, researchers have examined these behaviors more closely. How do they affect people? Are they linked to more well-known features of autism, such as difficulties with communication and social skills?

“It is possible that an intense focus on objects early in life drives the development of social communication challenges,” says Meghan Miller, Ph.D., a UC Davis MIND Institute professor. Miller led the study of how infants look at toys and other objects.

Does Having Repetitive Behavior Mean a Child Has Autism?

Many toddlers have repetitive behaviors, including those who are developing typically. “There are these quirky behaviors that many little kids have that could be considered repetitive behaviors, so they’re certainly not exclusive to autism,” says clinical psychologist Cynthia E. Brown, Ph.D., assistant professor at Pacific University. Brown has researched repetitive behaviors in children and teenagers in the SPARK autism study.

But in autistic children, these behaviors are usually more common, severe, and lasting.^2,3

To receive an autism diagnosis, people must have social communication differences, plus at least two of the following behaviors:

• Repetitive movements or sounds, such as spinning in circles, flicking their fingers in front of their eyes, grunting, or saying a phrase over and over.
• Insisting that routines, meals, or objects be exactly the same every day. Any change, no matter how small, may cause so much distress the child has a meltdown, an episode of yelling, crying, throwing things, kicking, or hitting.
• A very intense, or special, interest. Children may be described as obsessed with videos, wheels, animals, music, trains, or science, for example. Almost all children have at least one intense interest, which develops around age 5, on average, according to a study of youth in SPARK.⁴
• Over- or under-responding to one’s senses. Autistic people may find everyday lights, sounds, smells, or clothing textures overwhelming and uncomfortable. Or they may have the opposite reaction — barely noticing when a fire alarm sounds or seeking out sensory experiences.

Do Repetitive Behaviors Cause Problems?

Although many doctors focus on an autistic person’s social communication problems, repetitive behaviors “often have the greatest impact on individual and family functioning over the lifespan,” according to Eric Hollander, M.D., and Casara J. Ferretti, Ph.D., of the Autism and Obsessive Compulsive Spectrum Program at Montefiore Medical Center.⁵

Some repetitive behaviors can interfere with learning or cause stress and injury.

At school, some children may become upset and unable to focus if there is a new activity, a different teacher, or a change in schedule. If they have sensory sensitivities, then classroom bells, lunchroom smells, fluorescent lights, or a crowded hallway could be unbearable.

Some families may go to “unusual lengths” to avoid changes in routine, or in the home, that might lead to a meltdown.⁶

Dinnertime can quickly unravel if the only foods the child will eat are not available. Some parents say that they avoid places and activities that overwhelm their children’s sensory sensitivities.

These measures may temporarily reduce children’s distress, according to some researchers, but they also may prevent children from learning to cope with stress.⁷

Parents and doctors worry most about repetitive behaviors that lead to injury, such as head-banging, slapping, or biting oneself. A study of 17,851 children and teens in the SPARK autism study found that girls are more likely than boys to have behaviors that cause self-injury.⁸

A different study found that 12 percent of independent autistic adults reported repetitive behaviors that may hurt, such as picking at skin, nail biting, and pulling out their own hair.⁹

What Can Reduce Behaviors That Cause Problems?

Interventions based on Applied Behavior Analysis, a form of behavior modification, may reduce behaviors that cause harm or prevent a child from learning.

For instance, a behavior therapist may remove a favorite toy when the child bites his hand. Or, the therapist may reinforce a positive behavior, such as paying attention, by offering the child a toy or activity he likes.

One way to help children who insist on sameness is to reward them for gradually tolerating more changes in their routine. Children who must put their toys in a certain order could be rewarded for tolerating a small change in the order, and then, gradually, for playing with a toy.¹⁰

Can Repetitive Behaviors Be Helpful?

Yes, according to some researchers and autistic adults.

Researchers have found that engaging in a child’s intense interest can improve learning and appropriate behavior when it is used as a reward for finishing schoolwork or included in a social activity. A child who is fascinated with trains is more likely to interact with other children when they are playing with Thomas the Tank Engine, for example.¹⁰

Parents also report that special interests are helpful when their children engage in those interests by creating or building things, or by learning about them, according to a study of SPARK parents by Brown’s research team.¹¹ For instance, say an autistic teen has a passion for music: “You hear parents talking about how this is a pathway to a job or that he’s going to study this in school,” Brown says. “But you typically don’t hear that when someone has an intense interest in toilet flushing.”

There is evidence that repetitive behaviors can help autistic people manage emotions and lower their heart rate, a sign of reduced anxiety, says Miller, of the UC Davis MIND Institute.

Some autistic adults say that their repetitive behaviors or “stims” — rocking, flapping, or using a fidget spinner, for instance — help them handle sensory sensitivities and express themselves, according to a study in the United Kingdom.⁹

Stims “seem to help my focus move away from the outside sensory issues and allow me to ‘centre’ myself and my brain,” a 45-year-old autistic person told researchers. A 19-year-old autistic woman said that she stimmed when she felt “overwhelmed or overly happy or excited.”⁹

Many people view stimming behaviors that do not involve harm or meltdowns differently than they might have viewed them years ago. “There was a time when, if you saw kids who were rocking or walking on their toes, someone might say, ‘They need to stop doing that because it might be seen as odd.’ Maybe we’re seeing less of that message now,” Brown says.

What Ties Together Different Repetitive Behaviors?

The types of repetitive behaviors, from flapping to collecting science facts, vary widely. What links them together? Several researchers point to an inflexible way of thinking.^12-14

Of course, inflexibility is not unique to people with autism, according to the article by Hollander and Ferretti. “Individuals with inflexible thinking often become stuck in ritualistic or repetitive patterns of behavior. They have a need for sameness and order, and tend to focus intensely on their own thoughts, beliefs, and behaviors, often to the exclusion of all others,” they say.⁵

Could repetitive behaviors be one way an autistic person manages a world that was not quite designed for them?

Brown has studied intense interests, which many autistic people view positively. “These interests are seen as sort of sacred spaces that provide some relief from being in a world that’s not consistent with how their brain takes in information, a world that can get very overwhelming at times, and where they feel misunderstood,” she says.

Autistic author Pete Wharmby explains what special interests mean for him in his book, “What I Want to Talk About: How Autistic Special Interests Shape a Life.” Special interests are “the things that keep me going in life; the things that focus my energy, that keep me afloat, that calm me in times of stress, that thrill me in times of peace; the things that grasp and hold my attention like a dangled length of string occupies a kitten….”¹⁵

Interested in joining SPARK? Here’s what you should know.

Photo credit: iStock

References

1. Miller M. et al. J. Abnorm. Psychol. 130, 665-675 (2021) PubMed
2. Kim S.H. and C. Lord Autism Res. 3, 162-173 (2010) PubMed
3. Lam K.S.L. et al. J. Child Psychol. Psychiatry 49, 1193-1200 (2008) PubMed
4. Nowell K.P. et al. J. Autism Dev. Disord. 51, 2711-2724 (2021) PubMed
5. Hollander E. and C.J. Ferretti Psychiatric News 58 (2023) Article
6. Bishop S.L. et al. Am. J. Ment. Retard.112, 450-461 (2007)PubMed
7. Koller J. et al. J. Autism Dev. Disord. 52, 2505-2511 (2022) PubMed
8. Uljarević M. et al. J. Am. Acad. Child Adolesc. Psychiatry 61, 446-457 (2022) PubMed
9. Charlton R.A. et al. Res. Autism Spectr. Disord. 89, 101864 (2021) Abstract
10. Boyd, B.A. et al. J. Autism Dev. Disord. 42, 1236-1248 (2012) PubMed
11. Brown C.E. et al. J. Autism Dev. Disord. Epub ahead of print (2024) PubMed
12. Condy E.E. et al. Biol. Psychol. 148, 107739 (2019) PubMed
13. Mostert-Kerckhoffs M.A.L. et al. J. Autism Dev. Disord. 45, 3148-3158 (2015) PubMed
14. D’Cruz A.M. et. al. Neuropsychology 27, 152-160 (2013) PubMed
15. Wharmby P. What I want to talk about: How autistic special interests shape a life. London: Jessica Kingsley Publishers (2022)