Early Signs of Autism in Babies, Toddlers, and Young Children: A Parent’s Guide
Written by Behavior Frontiers as Part of Their Bright Futures Series
Understanding how your child is developing is one of the most important parts of parenting. While every child grows at their own pace, some early differences in communication, behavior, and social interaction may suggest signs of autism spectrum disorder (ASD).* Recognizing these signs early can help families connect with helpful resources and support earlier in their child’s developmental course.
In this guide, we’ll walk through typical developmental milestones and possible early signs of autism in infants, 1-year-olds, and toddlers aged 2 and beyond — along with tips for when to reach out for extra support.
What Is Autism?
Autism spectrum disorder (ASD) is a neurodevelopmental difference that shapes how a person communicates, interacts socially, and experiences the world around them. It exists on a spectrum, meaning characteristics can vary widely from child to child. Some children may show early signs in infancy, while others may display them later in toddlerhood or go undetected.
Why Early Detection Matters
Recognizing signs of autism early on can open the door to meaningful support. During the first years of life, the brain is especially flexible and ready to learn—making it an ideal time to strengthen communication, social, and learning skills through personalized care. Early identification can help you create a clear, confident path to support your child’s development and independence.
However, it’s important to know that growth is always possible. Children, teens, and adults with autism continue to learn, connect, and thrive at every stage. Whether you're just noticing signs in your toddler, seeing new behaviors in your 6-year-old, or have had questions for a while, the best time to take the next step is now. What matters most is moving forward—toward a future where your child feels understood, supported, and empowered.
Signs of Autism in Babies (0–12 Months)
Some early signs of autism may be noticeable as early as 6 months. While every child is different, a few developmental differences to be mindful of include:
By 6 Months:
Limited or no eye contact
Few big smiles or joyful expressions
Less engagement or response to caregiver’s voice or face
By 9 Months:
Minimal back-and-forth sounds or smiles
Limited use of facial expressions
By 12 Months:
Little or no babbling
Not responding to name
Not pointing, waving, or reaching to show interest
Not responding to sounds in their environment
Early Signs of Autism in 1-Year-Olds
Some children may show signs around their first birthday, such as:
Fewer spoken words or gestures
Less engagement with others during play
Not seeking comfort or connection when upset
Less interest in typical back-and-forth games (e.g., peekaboo)
If your child isn’t pointing to show interest or using gestures by 12 months, it may be helpful to bring it up with your pediatrician for guidance.
Signs of Autism in Toddlers (Ages 2–3)
As children grow, some early autism signs may become more noticeable. These may include:
Communication & Language:
Very few or no words by 16–24 months
Repeating words or phrases without clear meaning (echolalia)
Difficulty following simple directions
Social Interaction:
Limited interest in peers or group play
Preferring to play alone
Challenges sharing enjoyment or interests
Behavior & Repetition:
Repetitive movements like rocking, spinning, or flapping
Intense focus on certain objects or routines
Finding it hard to adjust to changes in routine
Sensory Responses:
Strong reactions to certain sounds, textures, or lights
Avoiding specific foods or types of clothing
Differences in how they respond to pain or temperature
Signs of Autism in Children Aged 4 and Up
As children grow older and face more complex social situations, some signs of autism may become easier to notice. Talking with your pediatrician can help you better understand your child’s unique development and explore any next steps, if needed.
Signs to look for may include:
Difficulty making friends or joining in play
Avoiding eye contact or missing social cues
Repeating phrases or behaviors frequently
Strong interest in specific topics or routines
Heightened sensitivity to sounds, textures, or changes
Finding back-and-forth conversations or understanding emotions challenging
Every child is unique. Having one or two traits doesn’t automatically mean a child is autistic—but sharing your observations with your pediatrician or a developmental specialist can offer valuable insight and support if needed.
Developmental Milestones Overview
What If My Child Misses a Milestone?
Children grow and develop in their own unique ways. Missing a milestone doesn't automatically signal a developmental concern. However, if you notice patterns or differences in areas like talking, playing, or social interaction, it’s a good idea to check in with your pediatrician.
The American Academy of Pediatrics recommends developmental screenings for autism during regular check-ups at 18 and 24 months. These screenings are quick, gentle tools that can help provide clarity and connect families with helpful resources.
Sometimes children appear to meet milestones and later show changes in skills around 18–24 months, like using fewer words or making less eye contact. Regular check-ins help make sure your child has the support they need to keep growing and thriving.
When Can Autism Be Diagnosed?
Autism can often be diagnosed reliably by age 2 by an experienced professional. However, early signs can sometimes be observed even earlier. If you have any concerns about your child’s development, reaching out to your pediatrician is a great first step. Early support can create even more opportunities for growth.
What To Do If You Notice Signs of Autism
If you notice early signs in your baby, toddler, or young child:
Talk to your pediatrician – Share what you’ve observed and ask about screening tools.
Track milestones – Use a tracker app or checklist from trusted sources like the CDC.
Consider an evaluation – A diagnostic specialist can offer clarity and help guide next steps.
Explore support services – Early intervention programs, including ABA therapy, can help children strengthen communication, social, and daily living skills.
Support for Every Stage
At Behavior Frontiers, we provide personalized autism services designed to help children build meaningful skills and confidence. Our caring clinical team is here to support your family through every step of your journey—from first questions to continued progress.
With full-day, center-based programs in a preschool-like setting for children up to age 6 and home-based services tailored to individual needs for children of all ages, we’re ready to help your child grow in ways that feel right for your family.
Think your child might benefit from personalized ABA services?
Schedule a free consultation today by calling 888-922-2843 or filling out the form below.
*Only a licensed specialist can provide an official diagnosis. If you have questions about your child’s development, we encourage you to speak with your pediatrician or a qualified diagnostician.