By Jeanine Weichelt, M.Ed., BCBA, Chief Clinical Officer, Helping Hands Family
The sooner you recognize the early signs of autism in toddlers, the sooner you can help your child develop their communication, social, and everyday skills. Services like early intervention and ABA therapy can play an important role during the toddler years, when children are especially receptive to learning.
This article covers what autism symptoms look like by category, how they tend to show up at 12, 18, and 24 months, and the steps you can take if you have questions about your child’s development.
Autism Symptoms in Toddlers by Category: Social, Behavioral, and Sensory
Autism Spectrum Disorder (ASD) affects how a child communicates, plays, moves, and responds to the world. Because it is a spectrum, symptoms look different from one child to the next.
Social and Communication Signs
These signs relate to how a child connects, shares attention, and communicates with the people around them.
- Does not respond to their name by 12 months
- Makes little or no eye contact during play or feeding
- Rarely points, waves, or reaches to share interest in something
- Shows limited back-and-forth play like peek-a-boo or rolling a ball
- Has delayed speech, or loses words they previously used
- Prefers to play alone and shows little interest in other children
- Has trouble understanding others’ feelings or expressing their own
Behavioral Signs
Autistic symptoms often show up in how a child moves, plays, and handles change. Common behavioral signs include:
- Repetitive movements such as hand-flapping, rocking, or spinning
- Lining up toys or objects rather than playing with them in varied ways
- Intense focus on one object, topic, or part of a toy, like a spinning wheel
- Strong distress when a routine changes, even slightly
- Repeating words or phrases heard elsewhere, known as echolalia
- Difficulty moving from one activity to the next
Sensory Signs
Many children with autism experience the world’s sensory input more or less intensely than others. Sensory-related autism spectrum symptoms include:
- Covering ears or becoming upset at everyday sounds
- Avoiding certain textures in clothing or food
- Seeking out deep pressure, spinning, or other strong sensory input
- Reacting strongly to bright or flashing lights
- Seeming not to notice pain, heat, or cold the way peers do
- Becoming overwhelmed in busy, crowded, or loud spaces
Early Signs of Autism in Toddlers by Age
The toddler years, especially between 12 and 24 months, are often when differences become easy to spot. Below is what parents commonly notice at each stage, alongside what is typical for that age.
Age | What you may notice | What is typical at this age |
12 months | No babbling or pointing; does not respond to name | Babbles, points at objects, turns to their name |
12 months | Little interest in peek-a-boo or simple social games | Enjoys back-and-forth games with caregivers |
15 months | No single words; limited gestures like waving | Uses a few words; waves, claps, and points |
18 months | Does not point to show you something interesting | Points to share interest, not just to request |
18 months | Little pretend play, such as feeding a doll | Begins simple pretend play |
24 months | No two-word phrases; loss of earlier words or skills | Combines two words like “more juice” |
24 months | Prefers to play alone, avoids other toddlers | Shows interest in playing near or with peers |
24 months | Repeats phrases rather than answering questions | Answers simple questions, follows two-step directions |
What to Do If You See These Signs
- Write down what you’re seeing, and when. Note specific behaviors and how often they happen. A short list of concrete examples is far more useful to a doctor than a general worry.
- Bring it up at your child’s next pediatric visit. Share your notes and ask for a developmental screening. You can request a validated tool, such as the M-CHAT, by name. A screening is quick and simply helps the pediatrician decide whether to refer your child to a specialist.
- Ask for a full diagnostic evaluation if the screening points that way. A developmental pediatrician, child psychologist, or pediatric neurologist can give you a diagnosis and talk you through the next steps.
- Start building skills in the meantime. You can begin supporting your child’s development at home or through your state’s available services right away. Once a diagnosis and referral are in place, getting started with ABA builds on that foundation.
Trust what you see day to day. You know your child better than anyone, and acting on your instinct to help your child is always the right call.
How Early Can a Child Begin ABA Therapy?
Helping Hands Family supports children who are 18 months and older. This early support is important because that’s when a toddler’s brain is at its most receptive, so skills like communication, imitation, and social connection develop more readily.
Your child will be treated by one of our Registered Behavior Technicians (RBTs) under the supervision of a Board Certified Behavior Analyst (BCBA), who designs and oversees the treatment plan. Sessions are play-based and built around your child’s interests, so ABA therapy feels natural and comfortable.
Frequently Asked Questions
When does autism appear?
Autism symptoms can appear as early as 6 to 12 months and are usually clear by 18 to 24 months. Some children show signs in infancy, such as limited eye contact or not responding to their name, while others develop typically and then plateau or lose skills, most often between 15 and 24 months.
What are the top three signs of autism?
The three signs most associated with autism are social communication differences, such as limited eye contact and delayed speech; restricted or repetitive behaviors, like hand-flapping or lining up toys; and sensory differences, meaning over- or under-reacting to sounds, textures, or lights. None of these signs confirms autism on its own. When you see a consistent pattern of these traits, though, talk to your child’s pediatrician.
Are there signs of autism at 18 months?
Often, yes. Signs of autism in an 18-month-old include not pointing to share interest, few or no words, limited pretend play, and repeating sounds instead of communicating. A screening tool like the M-CHAT is designed for this age. No single sign is conclusive, so a full evaluation is the way to be sure.
What are the early signs of autism in toddlers that parents miss most often?
The most commonly missed signs are subtle social ones: a toddler who does not point to share interest, does not respond to their name, or plays quietly alone without seeking connection. Because these children are often calm and undemanding, their differences can be mistaken for an easygoing temperament rather than a reason to look closer.
Do all autistic toddlers have speech delays?
No. Speech delay is common but not universal. Some autistic toddlers speak on time or early, yet still struggle with the social side of language, such as holding a back-and-forth conversation, reading facial expressions, or using words to connect rather than only to request. The absence of a speech delay does not rule out autism.
What is the difference between a speech delay and autism?
A speech delay affects how a child produces or understands language, but their social connection and play develop typically. Autism affects communication more broadly, including gestures, eye contact, shared attention, and social interest, alongside repetitive behaviors or sensory differences. A child with only a speech delay usually still points, shares, and seeks connection.
Should I wait for a diagnosis before starting therapy?
You don’t have to wait to take action. While ABA therapy itself requires a formal autism diagnosis and a doctor’s referral to begin, you can start the evaluation process, ask about screening, and build early skills through services like early intervention in the meantime.
Take the Next Step
If you’re seeing these signs in your child, you don’t need every answer before you reach out. We’re here to answer your questions and show you what starting with Helping Hands Family looks like.