For many parents, it begins with a familiar worry: "Something feels a little different, but I can't tell if it's a phase, a personality thing, or something I should look into."

That uncertainty is common. It is also why clinicians look for patterns across everyday skills, not one isolated milestone.

Instead of asking only "Are they meeting milestones," a more useful question is: How does my child use skills in real life?

• Do they communicate just to label, or to connect?
• Do they share attention with you, or stay in their own bubble?
• Do they play with you, or mostly beside you?
• Do routines work only when everything stays the same?

You may hear professionals talk about "adaptive skills," which are the practical skills that help a child function day to day. Tools like the Vineland Adaptive Behavior Scales are designed to measure adaptive behavior across domains like communication, daily living, and socialization. (You can see a publisher overview in the Vineland-3 brochure from Pearson.)

A quick reassurance: Seeing a few signs does not mean your child is autistic. Many toddlers show one or two items on a checklist during stressful seasons, sleep changes, language bursts, or big transitions. What matters most is the overall pattern, and whether it persists across time and settings.

Quick milestone red flags (6 to 24 months)

Many families search "early signs of autism" because they want a fast reality check by age. This is not a diagnosis list. It is a set of common patterns worth discussing if they are persistent.

By around 6 months

• Few warm, joyful expressions (smiles, laughter) directed at other people
• Limited back-and-forth facial expressions during play

By around 9 months

• Limited sharing of sounds, smiles, or other back-and-forth expressions
• Rarely "checks in" with you during play (little social referencing)

By around 12 months

• Limited babbling meant for social connection
• Few gestures like showing, pointing, waving, or reaching to be picked up
• Limited response to name most of the time

By around 16 months

• Few or no spoken words used meaningfully

By around 24 months

• Few or no meaningful two-word phrases (not just repeating)
• Limited pretend play, limited sharing, or minimal interest in people during play
• Words that appear but are not used to connect or share (more labeling than social use)

If a couple items fit, it can still be within typical development. If several fit, or the pattern is growing clearer over time, it is reasonable to ask for screening and a developmental evaluation pathway.

A note about girls: Autism can look different in girls, and some children may use "camouflaging" or masking behaviors, such as copying peers, staying very quiet, or working hard to blend in. If your gut says something is off, it is still worth discussing with your pediatrician, even if your child seems "fine" in public settings.

The patterns that tend to matter most

If you read only one section, please make it this one. Across ages 12 months to 4 years, clinicians often watch closely for:

1) Joint attention

Joint attention is the "shared spotlight" skill, two people intentionally focusing on the same thing for social connection. A clear definition and examples are available in UNC's ASAP resource on what joint attention is and why it matters.

In plain language, joint attention looks like:

• You point to a plane, your child looks at the plane, then looks back at you.
• Your child brings you a toy, not for help, but to share "Look!"

2) Gestures paired with eye contact

Pointing, showing, waving, reaching to be picked up, and nodding are early communication tools. The CDC's overview of signs and symptoms of autism includes several gesture and social-sharing markers parents commonly notice first.

3) Functional communication (not just word count)

A child can have words and still struggle to use communication socially. If that describes your situation, AIA's article on why a child can talk but still struggle socially is a strong next read.

4) Social reciprocity

Back-and-forth interaction, imitation, responding to name, and taking turns in simple routines.

5) Repetitive behaviors and intense rigidity

Repetitive movements, narrow interests, or big distress with small changes that interfere with daily life.

6) Regression

Loss of words, gestures, eye contact, play skills, or social interest is always worth discussing promptly with your pediatrician.

A helpful note about screening (18 and 24 months)

In the U.S., the American Academy of Pediatrics recommends autism-specific screening at 18 and 24 months, along with ongoing developmental surveillance. You can read that recommendation on the AAP's patient-facing page about autism screening recommendations at 18 and 24 months.

The CDC also summarizes that guidance for clinicians in its page on clinical screening for autism at 18 and 24 months.

Early signs of autism by age at a glance

12–24 months: early toddler years

This stage is often where families notice differences in how skills are used.

Communication signs (12–24 months)

Parents may notice:

• Limited eye contact during feeding or play
• Avoiding eye contact or rarely looking up to share a moment
• Fewer social smiles or facial expressions directed toward others
• Not smiling back when you smile or try to engage
• Rarely responding to their name consistently
• Limited babbling meant to connect (not just exploring sounds)
• Few or no words by 16–18 months, or words that are not used for connection
• Limited use of gestures (pointing, showing, waving)
• Difficulty communicating to request, protest, or share interest
• Less imitation of words or actions
• Inconsistent understanding of simple directions

Here is the nuance many families miss at first: communication is not just speech. A toddler can have words and still struggle with the social side of communication.

A helpful home example: Put a favorite snack in a clear container. Wait without rescuing right away.

• Do they look at you for help?
• Do they hand you the container?
• Do they point, gesture, vocalize, or try to pull your hand?

That "help-seeking" moment can tell you a lot about functional communication.

If transitions are a major trigger in your home, AIA's guide to First/Then cards for autistic children and smoother transitions can be an easy, practical tool to start with.

Social engagement and play (12–24 months)

You might see:

• Limited joint attention (not looking where you point, not showing items)
• Preference for playing alone most of the time (even with a caregiver nearby)
• Reduced interest in social games like peek-a-boo or pat-a-cake
• Difficulty copying simple play actions (rolling a car, feeding a doll)
• More observing than engaging

Joint attention is one of the earliest social building blocks. The CDC includes social-sharing examples like not showing you objects they like and not engaging in interactive games in its list of common autism signs parents may notice.

Sensory and big reactions (12–24 months)

Some early signs show up less in milestones and more in daily life.

You may notice:

• Getting very upset by everyday sounds, smells, tastes, textures, or bright lights
• Strong distress with everyday sounds (vacuum, blender, hand dryer)
• Intense reactions to textures (clothes tags, certain foods, grass, sand)
• Big upset with grooming routines (hair washing, nail trimming, tooth brushing)
• Avoiding or seeking certain sensations in a way that disrupts routines (covering ears, crashing, spinning)
• Seeming "fine" one moment, then melting down quickly in bright, busy places

Sensory differences alone do not equal autism. What matters is whether they cluster with social communication differences and repetitive or rigid patterns.

Object play and attachment patterns (12–24 months)

Toddlers love repetition, but some patterns stand out when they are intense, persistent, and hard to interrupt.

You might see:

• Lining up objects repeatedly (cars, blocks, cups) and becoming very upset if moved
• Focusing on parts of toys (spinning wheels, opening and closing doors) more than using the toy in pretend play
• Carrying an unusual object everywhere (a specific lid, string, spoon) and melting down if it is taken away
• An unusual attachment to objects that is hard to interrupt or replace
• Watching the same short movement over and over (spinning, dropping, rolling) rather than exploring varied play

If you are seeing a mix of play differences, sensory distress, and rigidity, it can help to track examples for your next pediatric visit.

Daily routines and flexibility (12–24 months)

You may notice:

• Difficulty transitioning between activities
• Strong reactions to small changes in routine
• Heavy reliance on adults for tasks peers are beginning to attempt

If routines feel fragile, it can help to build predictable structure while teaching flexible coping. For an ABA-informed approach, AIA's article on proactive and reactive ABA strategies for behavior support offers a parent-friendly framework.

2–4 years: preschool years

In preschool, the spotlight shifts to how skills come together: language + play + flexibility + early independence.

Communication signs (2–4 years)

Parents may notice:

• Delayed expressive language or unusual speech patterns
• Difficulty answering simple questions (especially "what happened?")
• Challenges with conversational turn-taking
• Repeating the same phrases or lines from shows (echolalia or scripting), sometimes without clear purpose
• Talking "at" people more than with them (lots of language, little back-and-forth)

At this age, the most useful question is often: Is my child using language to connect and share ideas, or mainly to label, request, or repeat?

If you want to delve deeper into the social side of language, AIA's article on pragmatic language differences in autism helps explain why "talking" and "social communication" are not always the same thing.

Socialization and play signs (2–4 years)

Common concerns include:

• Limited pretend or imaginative play
• Playing near peers more than with peers
• Rarely initiating interaction or sharing interests
• Difficulty understanding social cues or emotions

If play skills are a big question for your family, AIA's guide to play and leisure skills for children with autism offers concrete ways to build shared play step by step.

Sensory, coping, and regulation signs (2–4 years)

You might see:

• Getting very upset by everyday sounds, smells, tastes, textures, or bright lights, especially in busy environments
• Strong resistance to changes or transitions, especially after a sensory-heavy day
• Overwhelm in busy environments (birthday parties, loud stores, crowded playgrounds)
• Big emotional reactions to "small" changes, and difficulty calming once upset
• Extreme pickiness or distress around food textures, smells, or mixed foods
• Sensory seeking that becomes unsafe or disruptive (constant crashing, chewing non-food items)

Two AIA resources that pair well here:

• Why emotional regulation should be the heart of every ABA program
• Understanding sensory processing in the context of ABA therapy

Arizona aside: In Phoenix-area summers, outdoor time can shrink fast. On indoor days, you can gently practice flexibility with "tiny changes" (a different cup color, switching the order of two activities) and reinforce calm recovery. AIA's ABA summer routine tips for parents has season-specific ideas that fit Arizona families.

Object play, interests, and rigidity (2–4 years)

Interests can be a strength. The question is whether they become so narrow or rigid that they limit learning, play, or family routines.

You may notice:

• A very strong preference for one type of play (only letters, only numbers, only trains)
• Upset when play does not go "the right way" (scripts must be followed exactly)
• Repetitive play themes that do not expand (same scene, same order, same lines)
• Distress when a preferred object is not available, even when alternatives are offered
• Continued focus on parts of toys rather than flexible pretend play
• An unusual attachment to objects that drives routines or causes major distress when interrupted

What to track before you call your pediatrician

When you feel concerned, it helps to show patterns rather than general worry. For one week, jot down:

• What happened right before the behavior (noise, transition, demand, hunger, change)
• What your child did (gesture, words, crying, leaving, repeating)
• How long it lasted
• What helped (deep pressure, snack, break, First/Then, quiet space)
• Where it happens (home, store, daycare)

This kind of tracking lines up nicely with ABA thinking. If you want the parent-friendly version of "why behaviors happen," AIA's post on understanding behavior functions and behavior management is a useful companion.

Screening tools parents often hear about (and a key caution)

Many pediatric practices use the M-CHAT-R/F, a parent-report screening tool for toddlers. If you want the most accurate information straight from the source, use the official M-CHAT screening website and its page on how M-CHAT-R/F scoring works.

Important caution: The M-CHAT is copyrighted, and many copies floating around the internet are reposted improperly. The official site lists permissions and restrictions in its M-CHAT-R/F guidelines.

When an evaluation is the right next step

There is no blood test for autism. A comprehensive evaluation typically includes developmental history plus structured observation.

At AIA, you can learn about evaluation options on the page for autism evaluations in Arizona, including how the ADOS may be used as a structured observation tool.

If you want an outside clinical overview of ADOS-2 in plain language, Mass General's Lurie Center provides a helpful explanation of the ADOS-2 standardized assessment.

If your next question is "How do we even start," AIA's step-by-step page on the ABA therapy intake process and scheduling an assessment can make the logistics feel more manageable.

A final reassuring note for families

Noticing patterns does not mean something is "wrong." It means your child might benefit from support that fits how they learn, communicate, and cope with the world.

Early understanding helps families:

• build on strengths,
• support areas of need,
• feel informed rather than stuck in worry.

If you would like to talk through your observations with a local team, you can start with AIA's free client consultation form or explore more parent-friendly resources in the AIA Library.