Early Signs of Autism in Babies and Toddlers
The short answer
Autism spectrum disorder (ASD) can sometimes be identified as early as 12-18 months, though most children are not diagnosed until age 2-3. Early signs include limited eye contact, not responding to their name, lack of pointing or showing, limited social smiling, and absence of pretend play. Having one or two of these signs does not mean your child has autism - many typically developing children share individual traits. However, a pattern of multiple social communication differences warrants evaluation. Early intervention, regardless of eventual diagnosis, consistently leads to the best outcomes.
By Age
What to expect by age
At this age, autism is very difficult to identify because social development is still emerging. What to watch for is the development of social engagement: your baby should be making eye contact, smiling socially (not just reflex smiling), and showing interest in faces by 2-3 months. A baby who rarely looks at faces, does not smile back when you smile at them, or seems indifferent to social interaction may benefit from monitoring. However, many babies who are later diagnosed with autism appear typically developing in these early months.
Between 6 and 12 months, social communication skills develop rapidly. Key milestones to watch include responding to their name (consistently by 9-10 months), babbling with consonant sounds, sharing enjoyment by smiling and looking at you, and showing interest in social games like peek-a-boo. Differences that may emerge include not looking when you point at something, limited babbling, reduced interest in interactive games, and not using gestures like reaching to be picked up.
This is when some early signs become more apparent. The AAP recommends formal autism screening with the M-CHAT at 18 months and again at 24 months. Signs to discuss with your pediatrician include: not pointing to show you things (not just to request), no words by 16 months, limited pretend play, not following your pointing gesture, loss of any previously acquired skills (regression), and limited back-and-forth social games. Remember that late talking alone, without other social differences, is more commonly a language delay than autism.
By 18-24 months, the signs that may suggest autism become more distinct from typical variation. Children with ASD may not combine words by 24 months, may have difficulty with back-and-forth conversation-like babbling, may line up toys rather than play with them imaginatively, may be very focused on parts of objects (spinning wheels rather than driving the car), and may have strong reactions to sensory input (covering ears, avoiding textures). If the M-CHAT or your own observations raise concerns, request an evaluation.
Many children receive their autism diagnosis during this period. By age 2-3, social differences become clearer: limited interest in peers, difficulty with back-and-forth play, echolalia (repeating phrases without communicative intent), restricted interests, and rigid insistence on routines. An evaluation by a developmental pediatrician, child psychologist, or multidisciplinary team can provide a formal diagnosis and connect you with early intervention services. Research consistently shows that earlier intervention leads to better long-term outcomes.
What Should You Do?
When to take action
- Your baby is shy or slow to warm up in new situations but engages well with familiar people at home
- Your baby is a late talker but points, gestures, makes eye contact, and shows things to you
- Your toddler has one or two quirky behaviors (like lining up cars sometimes) but is otherwise socially engaged
- Your bilingual child has fewer words in each language but a combined vocabulary that is on track
- Your child flaps their hands briefly when excited but is otherwise socially connected and communicative
- Your baby is not consistently responding to their name by 12 months
- Your baby is not pointing to share interest (not just to request) by 14 months
- Your child has no words by 16 months or no two-word phrases by 24 months
- Your child has limited pretend play, does not imitate actions, or seems to prefer objects over people
- Your child has lost words, babbling, or social skills they previously had - any regression in development warrants urgent evaluation
- Your child has no babbling, no gestures, no eye contact, and no social engagement by 12 months - request a comprehensive developmental evaluation
Sources
Related Resources
Related Behavior Concerns
Not Making Eye Contact
Eye contact develops gradually over the first few months of life, and newborns can only focus on objects about 8-12 inches away. Most babies are making consistent eye contact and tracking faces by 2-3 months, so very young babies who seem to look past you are usually developing normally.
My Baby Isn't Responding to Their Name
Babies typically begin responding to their name consistently between 9 and 12 months. Before that, responses can be hit-or-miss, especially when your baby is focused on something interesting. The first step is always to check hearing, because hearing issues are common, treatable, and can look a lot like other concerns.
My Baby Isn't Pointing
Pointing typically develops between 12 and 14 months and is considered one of the most important social communication milestones. It shows your baby wants to share their world with you. If your baby isn't pointing by 18 months, a developmental evaluation is recommended - but there are lots of other ways babies start communicating that are worth noticing too.
Baby Hand Flapping - Normal or Concern?
Hand and arm flapping when excited, happy, or frustrated is extremely common in babies and toddlers and is usually a normal way of expressing big emotions before they have the words to do so. Most babies flap their arms at some point, typically between 6-24 months. Hand flapping becomes a concern only when it is very frequent, occurs outside the context of emotions, is accompanied by other developmental differences (limited eye contact, no pointing, no social engagement), or persists as the primary way of expressing emotion well past age 2.
Baby Not Sharing Attention (No Joint Attention)
Joint attention - the ability to share focus on something with another person - is one of the most important social-communication skills that develops between 9 and 14 months. It includes following someone's point or gaze, pointing to show you something interesting, and looking back and forth between you and an object. This skill is the foundation for language learning and social development.
My Toddler Is Aggressive Toward Pets
Toddlers being rough with pets is extremely common and almost never reflects true aggression or cruelty. Young children lack the motor control to be consistently gentle and do not yet understand that animals feel pain the way they do. With patient, consistent teaching about gentle touch and close supervision, most toddlers learn to interact safely with pets by age 3-4.