31 Signs of Autism in Babies: What to Look for & When to Ask a Dr.

With the increased prevalence of Autism, many parents are keener on monitoring their child’s behavior and developmental milestones from infancy. It can be overwhelming or confusing for parents when their babies miss important milestones, or they begin to notice peculiarities in their behavior.

If you type in “signs of Autism” in your search engine, there is a lot of clinical jargon and some negative conclusions about what might happen next. Contrary to what you might read from disconnected experts, those diagnosed with Autism have the potential to learn and grow.

This article aims to help parents understand the early signs of Autism in babies. What is the difference between typical development and atypical development? What are the early signs of Autism? What should parents do when they begin to notice irregularities in their baby’s development?

Early Developmental Milestones

Developmental milestones are behaviors and physical skills seen in babies and children as they grow. For example, rolling over, crawling, or talking are considered developmental milestones. Below you will find typical milestones for babies, the importance of tracking these milestones, and what can be considered normal variability in milestone achievement.

Typical developmental milestones for babies

How your baby plays, speaks, learns, acts, and moves offers important clues about his or her development.

By 2-months your baby should:

  • Calm down when spoken to or picked up.
  • Look at your face.
  • Be happy to see you.
  • Smile when you talk to her or smile at them.
  • Watch you as you move.
  • Look at a toy for several seconds.
  • Make sounds other than crying.
  • React to loud noises.
  • Hold her head up while on her tummy.
  • Move both arms and both legs.
  • Briefly open her hands.

By 4-months your baby should:

  • Smile on her own to get your attention.
  • Chuckle (not yet a full laugh) when you try to make her laugh.
  • Look at you, move, or make sounds to get your attention.
  • If hungry, open her mouth when she sees the breast or bottle.
  • Make cooing sounds such as “ahh” or “ooo”.
  • Make sounds back when you talk to her.
  • Turn her head to the sound of your voice.
  • Hold head steady without support.
  • Hold a toy when you put it in her hand.
  • Use her arm to swing at toys.
  • Bring her hand to her mouth.
  • Push up onto elbows or forearms when on her tummy.

By 6-months your baby should:

  • Know familiar people.
  • Like to look at herself in a mirror.
  • Laugh.
  • Put things in her mouth to explore them.
  • Reach to grab a toy.
  • Close lips to signal she does not want more food.
  • Take turns making sounds with you.
  • Sticks tongue out and blows bubbles.
  • Make squealing noises.
  • Roll from tummy to back.
  • Push up with straight arms when on her tummy.
  • Lean on hands to support herself when sitting.

By 9-months your baby should:

  • Be shy, clingy, or fearful around strangers.
  • Show several facial expressions, for example, happy, sad, or angry.
  • Look when you call her name.
  • React when you leave by crying or reaching for you.
  • Smile or laugh when you play peek-a-boo.
  • Look for objects when dropped out of sight.
  • Bang two items together.
  • Get to a sitting position unassisted.
  • Sit without support.
  • Move items from one hand to the other.
  • Use fingers to scrape food toward herself.

By 12 months your baby should:

  • Play games with you like pat-a-cake.
  • Put something in a container like a block in a cup.
  • Look for things he sees you hide.
  • Wave “bye-bye”.
  • Calls a parent “mama” or “dada” or another special name.
  • Understands “no” by pausing briefly when it is said.
  • Pull up to stand.
  • Walk by holding onto furniture.
  • Drink from a cup without a lid while you hold it.
  • Pick things up with a thumb and index finger, such as small pieces of food.

By 15 months your baby should:

  • Copy other children while playing.
  • Show you an object she likes.
  • Clap when excited.
  • Hug a doll or stuffed toy.
  • Show you affection by hugging or kissing you.
  • Try to use things the right way, such as a phone, cup, or book.
  • Stacks at least 2 small objects, such as blocks.
  • Tries to say one or two words other than “mama” or “dada”.
  • Look at a familiar object when it is named.
  • Follow directions when given with both a gesture and words, such as giving you an item.
  • Point to ask for something or to get help.
  • Take a few steps on her own.
  • Use fingers to feed herself.

By 18 months your baby should:

  • Move away from you but look to make sure you are close by.
  • Point to show you something of interest.
  • Put hands out for you to wash them.
  • Look at a few pages in a book with you.
  • Help you to dress her by putting an arm through a sleeve or lifting a leg.
  • Copy you doing chores.
  • Play with toys in a simple way, such as pushing a car.
  • Try to say three or more words besides “mama” and “dada”.
  • Follows one-step directions without any gestures.
  • Walk without holding on to anyone or anything.
  • Scribble.
  • Drink from a cup without a lid but may spill sometimes.
  • Feed herself with her fingers.
  • Try to use a spoon.
  • Climb on and off a couch without assistance.

By 2 years your baby should:

  • Notice when others are hurt or upset.
  • Look at your face to see how to react in a new situation.
  • Hold something in one hand while using the other hand.
  • Try to use switches, knobs, or button toys.
  • Play with more than one toy at the same time, like putting food on a plate.
  • Point to things in a book when asked.
  • Say at least two words together.
  • Point to at least two body parts when you ask her to.
  • Use more gestures than waving and pointing.
  • Kick a ball.
  • Run.
  • Walk up a few steps unassisted.
  • Eat with a spoon.

Importance of tracking developmental progress

Signs of autism in babies

When a child achieves developmental milestones within the expected age range, it signals typical progress in their development. If a child achieves milestones ahead of schedule, it can indicate advanced development compared to their peers.

Monitoring a child’s developmental milestones provides a comprehensive understanding of their progress and a solid foundation for assessing whether any concerns are justified. For example, changes in development may occur during significant life events, such as the addition of a sibling.

The most important reason to track a child’s development is to determine if they are developing as expected. Failure to reach milestones, or significant delays in reaching milestones can serve as the initial indicator of potential developmental delays in a child. Early identification of delays in development is crucial because early intervention can significantly improve a child’s skills, abilities, and overall prognosis.

Variability in developmental timelines

Developmental progress is not always steady so milestone monitoring should not be used in isolation. Babies and children develop along individual trajectories.  The milestone ages are based on the average age of when children learn a new skill. For example, for every child that walks “early”, another child will take their first steps “late”. In addition, milestones do not consider biological and environmental factors such as parenting style, culture, genetics, and social environment.

A study by Charles Super in 1976 found that babies in Kenya achieved motor milestones significantly earlier than those in America. The difference was attributed to the fact that babies are explicitly taught how to sit up and walk on their own much earlier. Conversely, Super (1976) also noted that babies in Africa acquire language at a later age than American babies, presumably because they are spoken to and encouraged to communicate less often than those in America. This study shows that the achievement of milestones can be affected by a child’s experience and environment.

Other sources of variability include differences in a child’s personality or temperament. For example, a child who has a quiet disposition may possess the necessary receptive language skills but will use expressive language minimally. A risk-averse child may take longer to achieve the milestone of walking when compared to an active child who seeks enjoyment from moving from place to place.

These variables that can affect a child’s development should be taken into consideration by interpreting milestone ages as a range of potential ages rather than a specific age. For example, a child can walk anywhere between 8 months and 18 months, but the average child takes their first steps at 12 months. The large age range is due to the need to master a series of prerequisite skills before walking can occur. These can include pulling up to a standing position, cruising, and balancing on two feet.

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Signs of Autism in Babies by Age

The following is a list of signs that your child is at risk for developing Autism Spectrum Disorder. However, it is important to note that sometimes neurotypical children may display some of these signs. One or a few of these being present does not directly indicate an Autism diagnosis.

1 to 6-Month-Olds

  • Poor eye contact – Eye contact is the source of the earliest possible signs of Autism in babies. Babies are born with an innate interest in the human face, particularly their parents and family.
  • No social smiling – Starting as early as their first month of life, a baby will reflexively smile back at you.
  • Limited display of affection – Babies may not respond to social cues like cooing or gestures like waving. Nor will they calm quickly when held by a parent or caregiver.
  • Sensory Issues – Babies may be sensitive to loud sounds or become overstimulated by different textures and lights.
  • Disinterest in surroundings – A sign of Autism is reduced interest in the environment, people, or objects. For example, not turning to locate where sounds are coming from.
  • Lack of tracking – Typically a baby will track an object (especially a red or brightly colored item) from side to side when it is moved within their field of vision.
  • Delayed or absent babbling – A baby may not laugh or make squealing sounds.
  • Lack of motor movements – Babies who do not grasp or hold onto objects, or bring their hands or objects to their mouths can be a concern.

7, 8 & 9-Month-Olds

  • Not looking to where a person is pointing – This skill is called joint attention and is often decreased in children with Autism Spectrum Disorder. If a baby’s gaze does not follow you when you are pointing it can indicate a developmental difference.
  • No social anticipation or peek-a-boo – A baby should raise their hands in anticipation of being lifted or become excited during peek-a-boo.
  • Limited facial expressions – By now, a baby should be smiling on their own or reacting with excitement, fear, or sadness to events.
  • No response to name – A baby of 9 months will turn their head and look at the person who has called their name.
  • No babbling – Delays in babbling are not common and serve as an indicator of Autism.
  • Avoidance of eye contact – Failing to make eye contact during interactions with parents and caregivers is a red flag worth mentioning to pediatricians.

1 Year Olds

  • Limited pointing/gestures – This entails difficulty or absence of pointing to objects or pictures of interest, not waving or shaking their head to communicate.
  • Speech development challenges – Limited or incomprehensible speech may be observed, there are no single words.
  • Limited imitation – They will not copy parent actions such as sweeping.
  • Receptive Language – They will struggle to understand simple instructions, e.g., “Give me the car.”


  • Walking – If a baby is not walking by 18 months old there is cause for concern.
  • Familiar objects – By this age a baby should recognize the function of common household items.
  • Attachment – It is a concern if the baby does not react negatively when parents or caregivers leave, or they are not excited when they return.
  • Language delay – At 18 months a baby should have at least 6 words not including “mama” and “dada”.
  • Loss of skills – At this point, some kids later diagnosed with Autism lose previously gained skills such as talking or gestures.

2 Year Olds

  • Peer interaction – Not getting excited around peers, prefers to play alone, little or no imaginative play.
  • Communication – A child may not use language to communicate or direct their speech towards others. They will engage in self-talk or scripting.
  • Language delay – An inability to use two-word phrases such as “More milk”.
  • Loss of skills – Parents can also begin to notice a loss of previously attained skills at this age.

Signs Not Related to Age

  • Routine – Babies and children may become upset with changed routines. For example, driving a new route, using a new cup, or bathing at an odd time.
  • Repetitive behavior – babies and children can display behaviors such as pressing a button repeatedly, or self-stimulatory behaviors such as jumping and spinning.
  • Play skills – Babies and children may interact with toys in unexpected or fixed ways such as lining up cars.
  • Intense interests – Babies and children can develop intense interests in objects or toys (dinosaurs, cars, letters).

When Should You Seek an Assessment for ASD?


If your child is displaying any of the above-listed signs, if you have concerns, if you are worried, or if it’s just a gut feeling the most important thing is to not minimize these concerns or feelings. Instead, bring these concerns to your pediatrician. Ideally, your pediatric primary healthcare provider should start screening your baby for signs of developmental or communication challenges such as Autism at his or her very first wellness check-up.

All children should be formally screened for Autism at their 9-month, 18-month, and 24-month wellness visits. Early assessments allow for early identification of developmental delays which can lead to early access to targeted interventions that directly address the child’s needs. However, developmental trajectories can vary widely, and some delays can resolve on their own which can lead to false Autism Spectrum Disorder diagnoses during these earlier assessments.

How Are Babies Tested for ASD?

During wellness check-ups, the pediatrician will observe how your baby giggles, looks to you for reassurance, tries to regain your attention during a conversation, points or waves, responds to his or her name, and even how they cry. These observations in combination with screening assessments and family history help identify babies at risk for Autism.

Multiple tools can be used to screen for Autism:

  1. Ages and Stages Questionnaire SE-2 (ASQ-SE2): This tool provides a quick look at how a child is progressing in key developmental areas, such as communication, gross motor and fine motor skills, problem-solving, and social skills. For over 20 years it has been used to identify children’s strengths and areas that need additional support.
  2. Pervasive Developmental Disorders Screening Test – II (PDDST-II): This is a 22-item questionnaire designed to be completed by parents or caregivers. It is typically used on babies aged 18 to 24 months old.
  3. Communication and Symbolic Behavior Scales Developmental Profile Infant/Toddler Checklist (CSBS- DP): This is a stand-alone tool, designed to be used for babies aged 9 to 24 months old. It is primarily designed to identify children who are at risk of developing communication and/or social impairments.
  4. Modified Checklist for Autism in Toddlers – (M-CHAT-R): This is a 23-item yes/no checklist to be completed by parents with babies of at least 15 months old. Unfortunately, this tool has been known to miss more subtle cues of Autism.

The Importance of Early Intervention For ASD

The earlier a child starts intervention, the smaller the delay which sets the child up for greater success and a better chance to catch up to same-age peers at a quicker rate. We should provide intervention before the gap becomes too large.

The timing of social communication development can make a big difference for kids with Autism Spectrum Disorder. Many parents expect their 1-year-old to be talking or saying a few words. Language gets delayed because the prerequisite social communication skills are delayed. Social communication refers to how we interact with one another.

These skills typically develop very early in a child’s development through interactions with primary caregivers during everyday activities. Some early examples of social communication development are:

  • Making direct eye contact
  • Sharing smiles with others
  • Babbling at people
  • Making gestures such as waving or pointing

Early signs of Autism include a lack of social communication skills. If these skills are not developing the child is missing out on opportunities to learn how to communicate for social purposes. For example, if a child does not understand or use gestures, he will likely have a problem with nonverbal communication when he gets older. If a child talks but only about special interests, he will likely have difficulty tuning into others.

A critical window to support the development of these skills is within the first three years of life. In this time a child’s brain is still forming and has increased plasticity. As a result, treatments have a better chance of being effective in the long term.  

Types of early intervention programs

The ideal intervention program for babies at risk of developing Autism occurs at home, involves parents, conducts periodic evaluations of the baby’s development, sets short-term therapeutic goals, considers all areas of the baby’s development, and is play-based. The Early Start Denver Model (ESDM) meets these criteria and has shown the greatest benefits to babies.

ESDM is an intervention program for babies as young as 12 months old that combines the concept of developmental milestones with Applied Behavior Analysis (ABA). ESDM is a play-based form of ABA therapy that incorporates play as a means to increase a child’s interest in activities and people. Through ESDM children learn that communicating with others is useful and positive. It aims to improve communication, play skills, and social skills such as self-expression.

Involvement of parents and caregivers

Discovering that your infant or child has Autism can be a challenging but also crucial moment for parents and caregivers. Early intervention and parent support play a significant role in the outcomes for babies and children. Most early intervention programs involve some aspect of parent training.

Support for Parents

It is important that parents who receive an Autism diagnosis not only seek intervention for the child but also a support system for themselves. It is natural for parents to feel fear and concern for the future of their child and family. However, parents should also remain hopeful. Behavioral and educational interventions can make a significant impact. Research continues to further refine and improve these therapies and offer new opportunities for children with Autism.

Parents should put their child before the diagnosis, and remember they are unique individuals with their own set of strengths and difficulties. Receiving an Autism diagnosis does not change the child you know and love. Continue to do things together that your child enjoys. While learning is important, shared enjoyment is also crucial for their development.

Parents need to build a strong support system. Find professionals you trust who will support your goals for your family. Other parents can also be good sources of informational and emotional support.

As you are educating yourself on Autism and therapy options you may discover contradictory and unfounded pieces of information. Ensure sources are credible and based on science. Don’t be afraid to ask questions and to advocate for what you think your child needs. Remember, you know your child best.


Autism is one of the most prevalent disorders today with 1 in 44 children being diagnosed each year. Parents should be actively involved in tracking their child’s milestones and looking out for key indicators such as lack of eye contact, disengagement from the environment, limited emotional reaction, limited facial expressions, repetitive behaviors, attachment to parents, and language delays. In addition, parents should ensure their healthcare providers conduct all necessary screens at 9-month, 18-month, and 24-month wellness check-ups. The earlier we notice children lacking skills, the earlier we intervene to provide the support to teach these skills the more likely it is that children will achieve their full potential. Individuals with Autism Spectrum Disorder can have fulfilling and productive lives and have strengths and abilities that individuals without autism may not possess.


Centers for Disease Control and Prevention. (2014). Learn the Signs, Act Early Program Checklist. Sourced from: https://www.cdc.gov/ncbddd/actearly/pdf/LTSAE-Checklist_COMPLIANT_30MCorrection_508.pdf.

Early Start Denver Model (ESDM). Retrieved from:

Jaeger, G. (February 20, 2019). Your child’s developmental milestones: why it’s “normal” to be different. Retrieved from: https://www.nordic.com/healthy-science/understanding-your-childs-developmental-milestones/.

Jones, W., & Klin, A. (December 19, 2013). Attention to eyes is present in decline in 2-6 month-old infants later diagnosed with Autism. Nature. 504 (7480): 427-431. Doi: 10.1038/nature12715.

Screening and diagnosis of autism spectrum disorder. (2020). Retrieved from: https://www.cdc.gov/ncbddd/autism/screening.html

Super, C. (1976). Environmental effects on motor development” the case of African infant precocity. Developmental Medicine and Child Neurology, 18, 561-567.

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