The short answer
Early signs of autism often appear well before a child's second birthday, and some can show up by 9 to 12 months. The most common early signs involve how a child connects with others: limited eye contact, not responding to their name, few gestures like pointing or waving, and delays in babbling or speech. No single sign means a child is autistic — but a pattern of them is a reason to talk with your pediatrician. Autism is now identified in about 1 in 31 children in the United States, according to the CDC, and the earlier a child gets support, the more it helps.
Below are the signs most worth knowing by age. Think of this as a guide for what to watch for and when to ask — not a checklist for diagnosing your child at home.
By 6 to 12 months
In the first year, the signs are subtle and social. You might notice limited eye contact, little or no smiling back when you smile, not turning toward your voice or responding to their name by 9 to 12 months, and few back-and-forth sounds or facial expressions. Reduced gestures — not reaching to be picked up, not waving — can also be early indicators.
By 12 to 18 months
This is often when patterns become clearer. Watch for no pointing to show you things ("look at that!"), not following your point or gaze, few or no words by 16 months, loss of words or skills a child previously had, and limited pretend play. Many children with autism are deeply focused on objects or parts of objects, line things up, or react strongly to changes in routine.
You do not need to be certain. If something feels off, that is reason enough to ask.
By 2 to 3 years and beyond
As children grow, signs may include limited interest in other children, difficulty with back-and-forth conversation, repetitive movements such as hand-flapping, rocking, or spinning, intense specific interests, strong reactions to sounds, textures, or lights, and a strong need for sameness. Some children develop typically and then plateau or lose skills — any loss of skills is worth discussing promptly.
What to do next
If you recognize a pattern here, the single most important step is to talk with your child's pediatrician and ask specifically about a developmental screening — you can request one, and you do not have to wait for the doctor to bring it up. You can also contact your state's early-intervention program directly, which can evaluate young children at no cost to families.
You do not need a diagnosis, and you do not need to be certain, to start asking questions. Early support changes outcomes, and the months spent waiting are months a young brain is most ready to learn. Trust your instincts: if something feels off, that is reason enough to ask.
How House of Hearts can help
House of Hearts ABA provides in-home and in-school ABA therapy for children ages one through eighteen, with no waitlist and most major insurance accepted. If you have a diagnosis and are exploring ABA, or you simply have questions about what you are seeing, we are glad to talk it through and point you in the right direction — even if that direction is a referral somewhere else first.
ABA is one of the most well-researched approaches for helping children build communication, social, and daily-living skills, and the earlier it begins, the more a child can gain. Reach out whenever you are ready.