Early Signs of Autism in Babies and Young Children

Did you know autism spectrum disorder (ASD) can be detected in babies, infants, and toddlers, yet many children don’t receive a diagnosis until the age of two or three? Because of that, it’s crucial to understand some of the early signs of autism in babies and children.

This article overviews the main signs of autism in toddlers, children, and even babies, helping more parents and caregivers get an early diagnosis for their little ones. Early intervention is the key to a healthy future for your child, so let’s learn all about it.

Diagnosing children with autism spectrum disorder (ASD)

The National Institute of Neurological Disorders and Stroke (NINDS) cites four major  symptoms of autism that pediatricians often use to diagnose children:

• Poor communication skills
• Restricted interests
• Stimming and repetitive behaviors
• Limited to no verbal skills

However, many of the above are almost impossible to see in a small baby who is not yet talking or developing interests. This means many parents do not seek a diagnosis until a later stage, and their child might miss out on the benefits of early intervention.

So, what are some of the visible signs of autism in babies? Let’s break down some of the things that parents can look out for.

Early signs of autism in babies

Every baby on the autism spectrum is different, but there are some common early signs of autism in babies that parents and caregivers can look out for.

These signs can vary depending on your baby’s age, so let’s take a closer look at what to watch for during each stage of development.

Signs of autism in infants 1 to 3 months old

Although it may be too early to make a correct diagnosis of autism, there are some signs of autism in 3-month-old babies to look out for. It’s rare to see signs of autism in newborns, but not impossible.

The earliest signs of autism in infants 1 to 3 months old may include:

• Limited engagement with caretakers: Babies may not respond to social cues like cooing or gestures such as waving and clapping.
• Reduced eye contact: Babies may avoid eye contact during activities like nursing and may be fussier and harder to comfort than neurotypical infants.
• Sensory challenges: Babies on the spectrum may experience distress from certain textures and sensory overload from noisy or flashing toys.

Signs of autism in babies 4 to 6 months old

While diagnosing autism at just 4 to 6 months can be challenging, certain early behaviors might raise concerns during this stage.

Some of the possible signs of autism in babies 4 months old—and up to 6 months—include:

• Limited eye contact: A lack of consistent eye contact during interactions with caregivers.
• Difficulty in social engagement: Infrequent smiling or responsiveness to social cues like cooing and facial expressions.
• Delayed or absent babbling
• Limited interest in surroundings: Reduced curiosity about the environment, people, or objects around them.
• Sensory sensitivities: Heightened sensitivity or aversion to certain textures, sounds, or lights.
• Lack of motor movements: Babies may not hold on to or grasp objects.

If you’re wondering about signs of autism in a 5-month-old, many of the same indicators may apply and become more noticeable as your baby grows.

Signs of autism in babies 7 to 12 months old

During the period of 7 to 12 months, certain signs may indicate the possibility of autism in infants. If you notice any delays in your child’s development, it’s best to consult your doctor.

Some early signs of autism in babies 7 to 12 months old are:

• Delayed crawling: Some babies with autism may delay their crawling compared to their neurotypical peers.
• Appearing unbalanced: Some infants with autism may appear unbalanced or struggle with standing, even with support.
• Avoidance of eye contact: Limited or avoiding eye contact during interactions with caregivers or others.
• Limited pointing: Difficulty or absence in pointing to objects or pictures to express interest or communicate.
• Speech development challenges: Limited or incomprehensible speech may be observed, with the child not reaching typical speech milestones.
• Lack of gestures: Babies with autism may refrain from using gestures such as waving or shaking their heads for communication.

Signs of autism in toddlers

Many toddlers with autism continue to show a progression of the symptoms first seen in infancy. As they grow, the signs of autism in toddlers may become more noticeable through behaviors like delayed speech, limited eye contact, or difficulty with social interaction. 

Autistic toddlers may also express frustration through tantrums or outbursts.

Diagnosing autism in toddler boys is significantly more common than in girls. During this stage of development, many children begin to show clearer symptoms associated with autism.

Signs of autism in 1-year-olds

Identifying signs of autism in a 1-year-old can be crucial for early intervention and support. Still, it’s important to remember that developmental timelines vary, and these signs alone do not confirm a diagnosis.

Let’s explore some of the most common signs of autism in toddlers aged 1.

Social interaction and communication challenges

• Avoids eye contact: May not look at parents, even when needing something.
• Doesn’t point or show objects: May not use gestures to share interest.
• Doesn’t respond to name: Might not react when called.
• Rarely gestures: May not wave or use age-appropriate gestures without prompting.
• Limited social smiling: May not smile back at others.
• Doesn’t imitate actions: May not copy things like pretend play or handwashing.
• Little to no babbling: May not babble or try to “talk” with caregivers.
• Struggles with simple directions: May not follow instructions like “Show me the car.”

Challenges in playtime

• Limited interest in playing with others: May not try to interact or get other children’s attention.
• Doesn’t initiate simple games: Games like peekaboo or chase may be missing.
• Lack of pretend play: May not engage in imaginative play, like feeding a toy baby.

Behavioral challenges

• Intense focus on certain toys or objects: May fixate on specific items.
• Repetitive play behaviors: Might spin wheels or line up toys repeatedly.
• Strong attachment to routines: Upset by changes, like a different route to familiar places.
• Overreaction to denied activities: May become distressed when not allowed to engage in favorite activities.
• Repetitive body movements: Includes hand-flapping, toe-walking, or arching the back.
• Heightened sensory sensitivity: Easily bothered by lights, sounds, or smells.

Signs of autism in toddlers 1 to 2 years old

Understanding and addressing signs of autism in the 1 to 2-year-old age range is exceptionally crucial for early intervention. The significance lies in the potential to provide timely support and interventions that can positively impact a child’s development. 

Let’s explore the most common signs of autism from 18 months to 2 years.

Communication and social challenges

• Avoids eye contact even when someone is speaking directly to them.
• Uses few sounds or gestures and may have limited or no speech.
• Doesn’t seek attention by pointing to objects or looking for approval.
• Prefers to play alone, often choosing solitary activities.
• Rarely responds to social cues like a parent’s smile or gestures.
• Doesn’t respond to their name when called.
• Strong preference for routine, often getting upset with changes like staying up late or weekend schedules.
• Struggles with social norms, such as approaching people without speaking.
• Clings to favorite people and may refuse to leave their side at social events.

Playtime challenges

• Shows little interest in pretend play (e.g., pretending to feed a baby).
• Avoids playing with other children or approaches them in an unusual way.
• Lacks awareness of personal space, such as taking toys without asking.

Behavioral challenges

• Displays repetitive behaviors (stimming), like hand-flapping, rocking, or finger-flicking.
• Struggles with joint attention, such as not following a parent’s pointing.
• Shows intense or obsessive interests, like collecting certain objects.
• Has strong attachments to specific items, like using only one cup or plate.
• Exhibits visual fixations, such as staring spells.
• More interested in objects than people.
• Sensitive to sensory input, reacting strongly to lights, sounds, or textures.

Signs of autism in 3-year-olds

Autism is typically diagnosed more frequently after the age of 3, as signs become more evident. Intervening at an early stage can contribute positively to a child’s development.

Signs of autism in 3-year-olds include challenges in social skills, communication skills, and behavior.

Social and communication signs of autism in a 3-year-old often include:

• Prefers to play alone and shows little interest in other children.
• Doesn’t share toys and may get upset if others try to play with them.
• Struggles with turn-taking and pretend play.
• Rarely initiates play, and when they do, it’s often by taking toys or approaching without speaking.
• Shows speech delays or regression, talking less than peers or not at all.
• Avoids eye contact with parents, peers, or strangers.
• Lacks facial expressions and rarely imitates others.
• Repeats words or phrases instead of holding a conversation (echolalia).
• Misuses pronouns, like saying “you” instead of “I.”
• Rarely uses gestures, even when prompted (e.g., pointing, clapping, waving).
• Doesn’t understand teasing or age-appropriate humor.
• Avoids physical contact and may react strongly to hugs or pats.
• Has difficulty expressing feelings or recognizing others’ emotions.

Common behavioral signs of autism in 3-year-olds include:

• Engages in repetitive behaviors like hand-flapping or rocking.
• Enjoys spinning or swaying for sensory input.
• Shows obsessive interest in specific toys or activities.
• Follows strict play patterns, such as lining up or stacking toys.
• Has a short attention span, especially for focused tasks.
• May seem hyperactive or unresponsive depending on the situation.
• Insists on routines and may become upset by changes.
• May show aggression during disruptions, including hitting parents.
• Engages in self-harming behaviors, like biting or head-banging.
• Has selective eating habits and may be extremely picky.
• Strong sensory sensitivities, reacting intensely to sounds, textures, smells, or tastes.

Signs of autism in 4-year-olds

As children grow, signs of autism may become more noticeable. Recognizing signs of autism in a 4-year-old is important, as early support can make a big difference in their development.

Let’s explore some common signs of autism at this age.

Challenges in social skills

Social signs of autism in a 4-year-old often include:

• Not responding to their name when called.
• Avoiding eye contact with parents, peers, teachers, or strangers.
• Preferring to play alone and reacting strongly when others try to join in.
• Struggling to share and not understanding turn-taking.
• Not engaging in pretend play, preferring real objects (e.g., using real food instead of toy food).
• Not sharing stories or talking about their experiences with their parents.
• Showing little interest in socializing with peers or engaging in interactions.
• Avoiding physical contact and reacting intensely to touch.
• Having few or no friends and showing no desire to make new ones.
• Rarely making facial expressions or showing inappropriate ones for the situation.
• Not being easily comforted and preferring to be left alone.
• Having difficulty understanding emotions and showing low empathy.
• Struggling to express emotions or talk about feelings appropriately.

Challenges in language and communication skills

Common language and communication signs of autism in 4-year-olds may include:

• Struggling to form sentences: By age 4, most children speak smoothly and are easily understood.
• Repeating words or phrases: While typical at earlier stages, by age 4, most children begin forming their own sentences.
• Responding inappropriately to questions or directions, such as going off-topic during conversations.
• Being unable to describe their feelings or explain what they’re thinking.
• Showing little interest in telling stories or talking about their day with their parents.
• Rarely using body language or gestures to communicate.
• Using reversed pronouns: For example, saying “you” instead of “I”; most children grasp pronouns by age 4.
• Struggling to understand age-appropriate jokes, even though children typically begin to enjoy and understand humor by this age.

Behavioral challenges

Some behavioral signs of autism in 4-year-old children may include the following patterns and reactions:

• Organizing toys and objects repetitively, often for a sense of comfort or predictability.
• Playing with toys in the same way every time, showing a preference for routine and structure.
• Getting upset by small changes in their routine, often reacting emotionally to disruptions.
• Performing repetitive movements, like hand-flapping or rocking, especially when anxious or overstimulated.
• Insisting on specific routines, relying on rituals to manage everyday life.
• Focusing intensely on specific interests, such as a favorite toy, show, or activity.
• Displaying impulsive behavior, acting without thinking about the consequences.
• Struggling to maintain focus and showing signs of restlessness during activities.
• Engaging in aggressive behavior, like hitting or biting, particularly when they can’t express their needs or feelings.
• Overreacting to sensory input, such as bright lights, strong smells, or loud noises.

Signs of autism in 5-year-olds

Most children on the spectrum are diagnosed by age 5. However, even if a diagnosis hasn’t been made, certain signs often become more noticeable when a child begins kindergarten or doesn’t reach expected developmental milestones.

Common signs of autism in 5-year-olds may include challenges in interacting with others, behavior, and communication.

When it comes to interacting with peers and others, signs of autism in 5-year-olds may include:

• Preferring to play alone, even when other children are nearby and interested in interacting.
• Struggling to engage in pretend play or create shared stories and scenarios with peers.
• Standing too close to others or not understanding when someone needs space.
• Not consistently responding to their name and seeming unresponsive in social settings.
• Avoiding eye contact or finding it uncomfortable during conversations.
• Showing little interest in forming friendships and preferring independent activities.

Some behavioral signs of autism in 5-year-old children may include the following:

• Engaging in repetitive movements like hand flapping or rocking.
• Having intense emotional reactions to changes in routine, such as during holidays.
• Avoiding physical contact or showing discomfort with hugs or touch.
• Developing deep, focused interests in specific topics or objects.
• Struggling to focus on tasks that don’t match their interests.
• Displaying irritability or aggression when unable to express emotions.
• Acting impulsively or showing signs of hyperactivity.
• Lacking a sense of danger and engaging in risky behaviors.

Common language and communication signs of autism in 5-year-olds may include:

• Using incorrect grammar or struggling with language beyond what’s typical for their age.
• Talking mostly about specific interests and showing little desire for back-and-forth conversation.
• Repeating words or phrases instead of using spontaneous language.
• Having difficulty reading or using body language.
• Struggling to form clear, concise sentences.
• Showing limited responses to others’ emotions.

Are autism signs in children different in boys and girls?

Early signs of autism are often more noticeable in boys than in girls. Research shows that only one in four children diagnosed with autism is female.

For every nine boys diagnosed with Asperger’s syndrome, only one girl receives the same diagnosis. Instead, many girls are misdiagnosed with social communication or developmental disorders.

When girls are diagnosed only with general developmental delays rather than autism, they may miss out on important resources and support.

It’s important to be proactive. If you notice signs that your daughter might be autistic—especially between routine medical check-ups—consider discussing your concerns with your pediatrician.

When can my child be diagnosed with autism?

According to the CDC, autism can be diagnosed as early as 18 months. Developmental screenings typically take place during wellness checkups at:

• nine months,
• 18 months,
• 2 years, and
• 3 years.

Many children receive a formal diagnosis around age two or three, often once social challenges become more noticeable—especially after starting school. But it’s never too late to seek a diagnosis and get the support your child needs to thrive.

If your doctor is unsure if a diagnosis of autism is appropriate for your child, the CDC recommends seeking a second opinion. The earliest interventions can serve as building blocks for your child’s future therapies and change your child’s developmental path.

The CDC emphasizes that the first three years of life are especially important. During this window, children are more likely to unlearn unhelpful behaviors and build new, positive habits.

It may take a bit of trial and error, but finding the right intervention—and the right therapist—can make a big difference.

Early interventions for autism

Once you’ve spotted the signs of autism and received an early diagnosis, you can consider the next steps. Psychiatrists, psychologists, and occupational therapists can all help support autistic children. 

Here are the most popular early interventions and therapies:

• Early Start Denver Model: ESDM is a relationship-based program that encourages positive feedback, shared activities, and parental involvement.
• Applied Behavioral Analysis: Many families use ABA, which encourages a positive reward system and parental engagement with the program.
• Picture Exchange Communication System: PECS teaches non-verbal and semi-verbal children to communicate via pictures and symbols.
• Verbal Behavioral Intervention: VBI is also used with children who struggle with speech, focusing on teaching verbal communication.
• Discrete Trial Training and Pivotal Response Training: DTT and PRT focus on behavioral and motivational challenges a toddler with autism may experience.
• DIR/Floortime Therapy: DIR helps children with autism connect with others by using their interests to improve engagement and communication, and strengthen thinking skills.

Timely intervention matters

Autism is usually diagnosed when a child misses key developmental milestones or shows signs of regression. However, some experts believe that signs of autism can appear even earlier in a child’s life.

While not all autistic individuals can be diagnosed as infants, recognizing autism symptoms in babies can lead to earlier support. An early diagnosis—especially before preschool—can make a significant difference in a child’s development.

If your baby shows even subtle signs of autism, start documenting them and share your concerns with your child’s doctor. The sooner autism is identified, the sooner families and professionals can begin using targeted interventions and therapies to support the child’s growth.

FAQs

Q: How early can you see signs of autism?

A: Signs of autism can be noticed as early as 12 to 18 months, but a formal diagnosis is typically made after age 3. Early detection during the first few years allows for more effective intervention and support.

Q: What are the early signs of autism in babies?

A: Early signs of autism in babies may include limited eye contact, difficulty with social interaction, such as not smiling back, and delays in reaching developmental milestones, including babbling and engaging in imaginative play. Sensory processing challenges, repetitive movements, and a lack of response to their name can be early indicators, too.

Q: Can autism be outgrown? 

A: Autism is a lifelong condition. However, early intervention and therapy can significantly improve a child’s skills and lead to a better quality of life.

Q: What is the biggest symptom of autism?

A: The primary symptom of autism is often characterized by challenges in social communication and interaction, coupled with engaging in restricted or repetitive behaviors and interests.

Other articles you may be interested in:

• Shaping the Future: Grandparents Diagnosing Autism
• Autism in Teens: Signs, Expectations, and Treatment
• Signs of Undiagnosed Autism in Adults
• How did I know my daughter was autistic?
• Autism Face: Are There Physical Signs?
• Do Babies with Autism Smile? Recognizing the Early Signs
• Is Chewing Clothes a Sign of Autism?