Early Signs of Autism in Toddlers (18–36 Months)

Noticing possible early signs of autism in toddlers can bring up a lot of questions, especially when your child is between 18 and 36 months and development seems to change quickly. Autism Spectrum Disorder can affect social communication, play, sensory processing, routines, and behavior, but every child’s profile is different.

What Milestones Matter Between 18 and 36 Months?

Developmental milestones are not a strict checklist. Children grow at different speeds. Still, they can help you notice when your child may need extra support. Early autism identification helps families notice early developmental patterns and seek guidance sooner. If you are trying to understand what you are seeing, this guide can help you sort through common signs, age-appropriate milestones, and next steps.

By 18 to 24 months, many toddlers are beginning to:

• Point to show interest, not just to request something.
• Use words, gestures, or sounds to communicate.
• Respond to their name most of the time.
• Bring objects to show a caregiver.
• Copy simple actions during play.

By 24 to 36 months, many toddlers are starting to:

• Use short phrases.
• Play simple pretend games.
• Notice other children.
• Follow simple directions.
• Share attention with an adult, such as looking back and forth between a toy and a parent.

One important skill is joint attention. This means your child shares focus with you, like pointing to a dog, looking at you, and then looking back at the dog. Challenges with joint attention can be one early clinical indicator of social communication differences.

For a broader overview of autism presentations, you may find this guide to different types of autism helpful.

Early Signs of Autism in Toddlers

Autism signs can look different from child to child. Some common signs between 18 and 36 months include:

• Limited pointing, waving, or showing objects.
• Not consistently responding to their name.
• Less interest in back-and-forth play.
• Repeating words, sounds, movements, or play routines.
• Strong distress when routines change.
• Intense interest in specific objects or parts of toys.
• Sensory sensitivities, such as covering ears, avoiding textures, or seeking spinning, jumping, or deep pressure.
• Limited pretend play.
• Difficulty using eye contact along with gestures and words.

The CDC lists social communication differences and restricted or repetitive behaviors among common autism signs. Eye contact alone is not enough to identify autism, because children communicate in many ways. It is more helpful to look at the whole pattern.

How Autism May Look Different in Girls

Many autism descriptions were built around patterns more often noticed in boys. Girls may show signs that are easier to miss.

For example, a toddler girl may copy other children’s play, use memorized social phrases, or stay close to peers without fully joining the interaction. She may have intense interests that seem typical on the surface, such as animals, dolls, or books, but the depth or repetition of the interest may stand out. Older labels like low-functioning autism are still searched often, but many families and professionals now prefer language that describes specific support needs.

A Neurodiversity-Affirming Way to Think About Signs

Autism is not a parenting failure, and it is not a child being “bad.” A neurodiversity-affirming view recognizes that autistic children may experience communication, sensory input, and routines differently.

The goal is not to make your child seem less like themselves. The goal is to understand what they need to feel safe, communicate, learn, and participate in family life.

Some families also hear support levels during diagnosis. These can be confusing, so guides on Level 1 autism and Level 2 autism may help explain the terms.

What Parents Can Do Next

If you have concerns, you do not need to figure everything out alone.

1. Write down what you notice. Include communication, play, sensory reactions, sleep, eating, and routines.
2. Talk with your pediatrician. Ask about standardized screening and whether a developmental referral is appropriate.
3. Contact early intervention. In many areas, children under 3 can be evaluated through early intervention programs without waiting for a full autism diagnosis.
4. Call your insurance plan. Ask what autism evaluations, speech therapy, occupational therapy, and behavioral services require for coverage.
5. Join waitlists early. Diagnostic waitlists can be long, so it can help to schedule now and cancel later if support is no longer needed.
6. Ask what you can start now. Parent coaching, speech support, occupational therapy, or autism therapy at home may help your child build skills during the waiting period.

Support You Can Use While Waiting

Small, steady supports can make daily life feel more predictable.

You may try:

• Using simple visual routines for meals, bedtime, or leaving the house.
• Offering choices with pictures, objects, or short words.
• Watching what your child is trying to communicate through behavior.
• Reducing sensory overload when possible.
• Practicing short, playful back-and-forth interactions.

If concerns continue, a professional evaluation can help clarify what your child needs. Early support does not label your child in a negative way. It gives your family more tools, more understanding, and a clearer path forward.

References

• National Library of Medicine: Incremental Utility of 24-Month Autism Spectrum Disorder Screening After Negative 18-Month Screening
• National Library of Medicine: Early and Repeated Screening Detects Autism Spectrum Disorder
• PubMed: Autism screening at 18 months of age
• PubMed: Description of Clinician-Diagnosed Regression at Time of Autism Spectrum Disorder Diagnosis in Toddlers

Sarah McConkie

Sarah McConkie is a Board Certified Behavior Analyst and Clinical Director at Aviation ABA with years of experience supporting children and families through individualized ABA therapy. She has worked across multiple clinical settings, conducting behavioral assessments, developing treatment plans, and supervising therapy teams to help children build important everyday skills. Sarah is passionate about creating supportive, relationship-focused care that helps children feel comfortable, confident, and successful in their daily lives.