You noticed something. Maybe your child does not turn when you call their name, or does not point at the dog in the park, or seems to play beside other children rather than with them. You are scanning this on your phone, probably late, wondering whether you are overreacting. You are not. This page is the list clinicians use, by age, in plain language.
What clinicians actually look for
Most early signs of autism come down to a handful of skills that show up in the second year of life. They are about connection, not intelligence.
- Joint attention. Looking where you look, following your point, and pointing to show you something (not just to get it).
- Response to name. Turning when you say their name, most of the time, without a touch or a toy to help.
- Gaze. Looking at your face during play, checking back with you when something surprising happens.
- Play. Copying you, playing peek-a-boo, pretending (feeding a doll, "driving" a block).
- Language. Babbling, then gestures, then words, and using them to communicate with you rather than only to repeat.
The Public Health Agency of Canada lists the same core areas: little babbling, little eye contact, more interest in objects than people, appearing not to hear when spoken to, limited interest in other children, and repeating words without seeming to understand them. official
Signs by age
Every child develops at their own pace, and a single missed item is not a diagnosis. Look for patterns, and for skills that are absent most of the time rather than skipped once.
| Age | What most children do | What to watch for |
|---|---|---|
| 12 months | Babble with back-and-forth sounds, turn to their name, look at your face, wave or reach | Little or no babbling, no response to name, little eye contact, more interest in objects than in people |
| 18 months | Point to show you things, follow your point, use some words, copy simple actions | No pointing to share, not following your point, no words, not copying, not responding to name |
| 24 months | Combine two words, pretend play, show interest in other children, share enjoyment with a look | No two-word phrases, no pretend play, limited interest in other children, unusual repeating of words or phrases |
| 36 months | Short conversations, play with peers, flexible routines, ask questions | Speech that is mostly repeated from TV or others, needing things exactly the same way, strong reactions to small changes, lining up or spinning objects for long periods |
Two things at any age deserve their own line: losing words or skills the child used to have, and strong reactions to sounds, textures or light. Canada's official signs list includes both. Loss of skills is covered on its own page: Lost words and skills. official
Why 18 to 24 months matters so much
Here is the fact that changes what a worried parent should do. The signs above are visible and reliable earlier than most people think, and the diagnosis usually comes much later.
- In a large study that screened every toddler at a network of pediatric clinics, an autism identification made at 14 months or later held up in most children when they were re-assessed up to age 3. strong
- The standard screening questionnaire, the M-CHAT-R/F, was validated at the 18 and 24 month well-child visits. strong
- In Canada, the median age of an autism diagnosis is 3.7 years, and only just over half of diagnosed children were diagnosed before age five. official
That distance between "signs visible at 18 months" and "diagnosis at nearly 4" is the parent's window. Nobody else is watching your child every day. The window is not a countdown, and it is not a deadline you can miss. It is simply the period when what you notice matters most, because you are the one noticing.
Permission to act before you are sure
You do not need to be certain, and you do not need to have ruled out everything else. The referral system is built for uncertainty. A referral is a request for someone qualified to take a closer look, nothing more.
Consider what each path costs:
- You ask for a referral and it turns out to be a language delay or nothing at all. You lost an afternoon and gained a professional's reassurance.
- You wait a year to be sure. You spend that year worried anyway, and the assessment queue in Quebec starts a year later.
The same study that found a diagnosis becomes stable by 14 months also found that roughly one child in four who was later identified as autistic had not been flagged at their first visit. Early screening catches a lot, and it misses some. A parent who keeps watching, and keeps asking, closes that gap. strong
What this does not tell you
- It does not tell you your child is autistic. These are signs that justify an assessment, not a verdict.
- It does not tell you what your child's future looks like. Early language is not destiny; trajectories change through childhood, and many family-history infants develop typically. moderate
- It does not replace hearing and vision checks. A child who does not respond to their name needs their hearing tested, too. Ask for both.
If your child is a girl, or quiet and compliant, the signs can be softer and easier to miss. See Girls, quiet kids and masking. If your child also seems very active or has a language delay, the labels overlap a lot at this age and that is fine: Autism, ADHD and language delay at age 2.
Where to start in Quebec
The public route starts at your CLSC (call your local one, or 811 to be directed) or with your family doctor or pediatrician. The Agir tôt program takes children under 7 without a diagnosis, on a voluntary basis and free of charge. official For the script to use at the appointment, and what to bring, read What to say to your doctor. The journey hub for this moment is I'm worried.
This week
- Write down, with dates, the three things you noticed most. Two lines each. Bring the note to any appointment.
- If your child is 16 months or older, fill in the M-CHAT-R/F (free, in French-Canadian and English). See M-CHAT-R/F explained.
- Call your CLSC or family doctor and ask for a developmental referral and a hearing test. Use the exact sentence "I'd like a referral documented today."
Sources
- Autism: Signs and characteristics — Public Health Agency of Canada, accessed 2026
- Autism spectrum disorder: Highlights from the 2019 Canadian Health Survey on Children and Youth — Public Health Agency of Canada, 2022
- Evaluation of the diagnostic stability of the early autism spectrum disorder phenotype in the general population starting at 12 months — Pierce et al., JAMA Pediatrics, 2019
- Validation of the Modified Checklist for Autism in Toddlers, Revised with Follow-up (M-CHAT-R/F) — Robins et al., Pediatrics, 2014
- Mid-childhood developmental and behavioural outcomes in infants with a family history of autism and/or ADHD — Charman et al., Journal of Child Psychology and Psychiatry, 2026
- Agir tôt program — Gouvernement du Québec, accessed 2026