Recognizing Signs and Traits of Autism in Children

Traits of autism in children may include having speech differences, social communication difficulties, sensory sensitivities, behavioral differences, and more.

Autism can be reliably diagnosed by a specialist by age 2, but the average age of autism diagnosis in the U.S. is 5 years. However, more and more teens and adults are receiving diagnoses as the mainstream picture of autism shifts. A child who is accurately diagnosed as autistic won't lose that diagnosis as an adult—autistic children grow up to be autistic adults.

A child playing with a toy at the table

Agrobacter / istock 

This article discusses autistic traits and signs of autism in kids, the age at which these may be seen, and what to do if your child shows autistic traits.

What Does Autism in Children Look Like?

Autism is known as a “spectrum” disorder because no single trait is common to all and there is wide variation in the intensity of traits people experience.

Autism is a developmental disorder, which means that no single trait or behavior, on its own, is likely to suggest a child is autistic. These differences must be significant to qualify for a diagnosis. They must strongly impact the child's ability to do age-appropriate tasks, make friends, or succeed at school.

Speech Differences

Autistic children almost always have some kind of speech difference. For example, they may:

  • Only communicate non-verbally
  • Have speech delays
  • Speak with unusual prosody (the rhythm, stress, and intonation of speech), such as sounding flat or monotone
  • Memorize and repeat speeches from television or other people's conversations

They may also speak very quickly, say the same thing over and over again (echolalia), or use incorrect grammar when they should be old enough to speak correctly.

Social Communication Difficulties

Autistic children always have social communication difficulties, which can show up in many different ways:

  • They may not want to interact with anyone at all, preferring to spin, line up objects, continually flush the toilet, or read.
  • They may want to interact all the time and have a harder time picking up on boundary cues.
  • They may insist on getting their way and pursuing their own interests all the time.
  • They may be very passive.

Autistic children may take longer than their peers to learn to play with—rather than near—other children.

Sensory Sensitivity

Most autistic children have some kind of sensory sensitivity, such as:

  • Craving or avoiding loud noise, hugs, certain flavors, textures, or smells
  • Being ultra-sensitive to light
  • Being easily distracted by small sounds and movements

Some autistic children are very distressed by sensory input of all types that others may not even notice—like a scented deodorant, appliances humming, etc.

Unusual Movements

Autistic children often (though not always) move differently than other children. "Stims" (short for self-stimulation) are common and may look idiosyncratic to people unfamiliar with neurodiversity.

For example, while many children may suck their thumbs, bite their nails, or twirl their hair, autistic children may additionally be likely to flap their hands, run on their toes, or rock back and forth.

Autistic children are also more likely to walk stiffly with their hands held still at their sides or run with an awkward gait. They may be clumsy and have difficulty throwing, catching, writing, or drawing.

Behavior Differences

Autistic kids behave differently from their typical peers. While neurotypical (the usual way of processing information) children may tantrum to get their way (or because they are tired or hungry), autistic children are more likely to have meltdowns or tantrums because they are overwhelmed, frustrated, or unable to communicate their needs.

Other behavioral differences may include:

  • Having interests associated with people older or younger than them
  • "Perseverating," meaning they say or do the same things over and over in exactly the same way or get "stuck" on a thought, idea, interaction, or desire
  • Thriving on routines and getting very upset when normal routines are changed
  • Becoming emotional over small things and having a lower tolerance for stress

Even a teen or adult may suddenly burst out crying over a change in plans or a forgotten water bottle. In some cases, autistic children can be impulsive or self-harming or they may run away (called "eloping") for reasons that are unapparent to parents or peers.

Style of Play

Autistic children often play differently than their peers. They may:

  • Play all alone and find it difficult or even impossible to engage with other children
  • Play by organizing or lining up objects, stuffing them into containers, or wandering around the yard or playground tossing dirt into the air

They may find it difficult to follow the rules of sports like soccer or baseball.

You can't recognize an autistic child by their looks. Autistic children can be silent, chatty, incredibly intelligent, have intellectual disabilities, or very sociable.

Behaviors and mental processing of autistic children can range from quirky to very atypical. They may do well academically and/or have learning disabilities.

At What Age Do Kids Show Signs of Autism?

Many children show symptoms of autism by 12 to 18 months of age or earlier. Autism can be reliably diagnosed by a specialist by age 2, but the average age of autism diagnosis in the U.S. is 5 years.

It's important to get a diagnosis as early as possible because research shows that early detection and intervention greatly improve outcomes.

Some early traits of autism include:

  • Problems with eye contact
  • No response to their name
  • Problems following another person's gaze or pointed finger at an object
  • Poor skills in pretend play and imitation
  • Problems with nonverbal communication

Sometimes autism traits become apparent in school-age children. Later traits of autism may include:

  • Difficulty taking turns in conversations
  • Difficulty following instructions with more than one or two steps
  • Speaking differences, such as talking too loudly or monotone
  • Avoiding eye contact
  • Having few facial expressions or gestures
  • Difficulty reading non-verbal cues
  • Difficulty making friends and having few or no friends

Why It Is Important to Recognize Autism in Children

There are several reasons why it's important to recognize, diagnose, and support autistic children. Here are just a few:

  • Understanding the reasons behind your child's behaviors and challenges can help you better understand what your child needs to thrive. 
  • Schools and health insurance companies provide a wide range of free services to autistic children which would not be available to a child labeled as having "delays."
  • Social Security and other agencies may be able to help you meet your child's particular needs.
  • Autism is now so widely known that many non-profits and corporations specifically cater to the needs of families with autistic children. Once you understand your child's diagnosis, you will quickly discover autism-friendly programs ranging from sports teams to movie nights to special days at the zoo.
  • When you know your child's diagnosis, you can find support programs and groups run by autistic adults and meet neurotypical and autistic parents with similar experiences. Not only will you discover resources you never knew about, but you may also find new friends—both for yourself and your child.

Is Autism Different in Boys and Girls?

The diagnostic criteria for autism don't outwardly discriminate based on gender. However, research suggests that autism may look quite different in girls, making it difficult to diagnose using existing criteria. This is because participants were boys in most early studies of autistic children.

If You Think Your Child May Be Autistic

Based on the description above, you may feel that your child should be evaluated for autism. If that's the case:

  • Read about the traits, not "symptoms," of autism to be sure that you're accurately understanding how autism differs from other developmental disorders.
  • Talk with your pediatrician to find out whether they agree with your assessment—and ask for recommendations for practitioners or clinics that can conduct an evaluation. If your pediatrician disagrees with you, understand why and be sure you agree. If you don't agree, move on to the next step.
  • Talk with your school district to determine whether they have facilities to evaluate your child free of charge. If not, they may be able to recommend a clinic or practitioner that they work with.

Don't be shy about asking for an evaluation if your child is autistic. If your child is otherwise neurodivergent, you can get them the support they need. If your child is simply developing differently, you continue to pay attention to their needs and behaviors.

In short, an evaluation can only help. And, since it's usually possible to have your child evaluated for free, there's nothing to lose.

Summary

Traits of autism in children may include delayed or not reaching developmental milestones, speech differences, social communication difficulties, sensory sensitivities, and behavioral differences.

Early diagnosis is key to early intervention which greatly improves outcomes. If your child shows traits of autism, talk with your child's pediatrician and/or school district administration about getting an assessment if warranted, referrals, and available resources.

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Autism Speaks. Autism statistics and facts.

  2. Centers for Disease Control and Prevention. Signs and symptoms of autism spectrum disorders.

  3. National Institute of Mental Health. Autism spectrum disorder.

  4. Autism Speaks. Sensory issues.

  5. National Institutes of Health. When do children usually show symptoms of autism?

  6. Australian Parenting Website. Autism: signs in older children and teenagers.

  7. Social Security Administration. Apply for disability benefits - child (under age 18).

  8. Werling DM, Geschwind DH. Sex differences in autism spectrum disordersCurrent Opinion in Neurology. 2013 Apr;26(2):146. doi:10.1097%2FWCO.0b013e32835ee548

  9. Centers for Disease Control and Prevention. Screening and diagnosis of autism spectrum disorder.

Additional Reading

By Lisa Jo Rudy
Lisa Jo Rudy, MDiv, is a writer, advocate, author, and consultant specializing in the field of autism.