Understanding Autism Spectrum Disorder: Early Signs Every Parent Should Know
Early childhood is a time of accelerated growth and learning for children. It is during this period that several critical windows of neural development open and then close, offering a unique opportunity for parents and and those who support them to intervene when differences in neurodevelopment become noticeable. For this reason, there have been increasing efforts across medicine, educational settings, and parent-focused resources to improve awareness of early signs of autism in childhood.
This post is designed to support those efforts by helping parents better understand signs of autism in toddlers—what they can look like, how they may show up over time, and when it may be appropriate to seek a diagnostic evaluation.
Key Points
Early identification of autism can support improved developmental outcomes
Routine autism screening is recommended at 18 and 24 months during well-child visits
Signs of autism in toddlers often include differences in social communication, language development, play, behavior, and sensory responses
Boys and girls may present differently, with girls often showing fewer overt repetitive behaviors and more subtle social differences
Early, individualized interventions can support communication, social development, and daily functioning
Each child with autism is unique, with their own strengths, challenges, and developmental trajectory
What is Autism Spectrum Disorder
Autism, also known as autism spectrum disorder (ASD), is a neurodevelopmental condition characterized by differences in social communication and social interaction, as well as restricted and repetitive patterns of behavior, interests, or activities.
When autism was initially described, it referred primarily to more severe presentations, in which children were nonverbal or minimally verbal and often had co-occurring intellectual disability. Over time, clinicians and researchers have come to recognize a much broader range of social communication differences and behavioral patterns that fall within the diagnosis.
This expanded understanding is reflected in the term spectrum, which captures the wide variability in how autism presents. Individuals with autism may differ significantly in their strengths, challenges, and the specific combination of traits they exhibit.
Why Early Detection Matters
A number of clinical studies conducted over the last several decades, including several completed more recently, have shown that the earlier a child with ASD receives appropriate interventions, the better their developmental outcomes. These improvements can include gains in communication (such as level of spoken vocabulary and receptive language skills), social skills and behavior (including joint attention and level of play) and broader developmental outcomes, such as gross motor functioning, cognitive and adaptive functioning, and self care.
Some of the more striking findings suggest that a subset of children who receive interventions by ages 2 or 3 no longer meet criteria for a diagnosis of ASD by early adulthood. Although such outcomes are not common, the literature consistently supports identifying autism, and accessing evidence-based interventions, as early as possible.
Signs of Autism in Toddlers
Social Communication Differences
Limited eye contact
Not consistently responding to name (when you call your child’s name, they do not look at you)
Reduced joint attention (e.g., not pointing to show interest, not make eye contact to attract your attention, not responding to your efforts to share attention to objects of interest)
Fewer facial expressions or non-verbal gestures (use of body language, pointing, or waving)
Language and Communication Patterns
Delayed speech or limited words
Repetitive or scripted speech (e.g. echolalia/just repeating back what you have said, only quoting songs or movies, or appearing to use a greeting ritual/rehearsed and repetitive sentences for communication)
Behavior and Play
Repetitive movements (hand flapping, posturing)
Strong preference for routines (e.g. using the same exact sequence of steps for bedtime routines)
Difficulty with changes or transitions (distress, such as prolonged tantrums, during bedtime routines, leaving the home for school, disengaging with a preferred activity, etc)
lack of imaginative play (pretend play, dress-up)
lining up toys
a strong interest in the parts of toys rather than what the toy does (spinning wheels of a toy car, rather than pretending it is driving)
Sensory Differences
Extreme sensitivity to and avoidance of sounds, food or clothing textures, lights (e.g. refuses to wear certain clothes due to their texture, afraid of the toilet flushing, extremetly restricted diet due to avoiding food textures)
Seeking sensory behavior (spinning, touching, smelling, rubbing up against people or objects)
It’s important to keep in mind that autism is diagnosed when a child shows a pattern of multiple symptoms that are present with sufficient frequency and severity to meet established clinical criteria. No single symptom, in isolation, is enough to support a diagnosis of autism.
Do Signs Differ in Girls vs Boys?
This is a complex subject, with many years of research attempting to answer whether, and how, autism differs in girls/females and boys/males. The short answer is that yes, in general, symptoms of autism may present differently in children assigned female at birth compared to those assigned male at birth.
When considering children with average or above average IQ, females with autism often demonstrate fewer overt restricted and repetitive behaviors and may show relatively stronger social communication skills, greater cognitive flexibility, and a tendency toward more socially adaptive behaviors.
At the same time, some studies suggest that females may experience higher rates of internalizing symptoms, including compulsive behaviors, and, in some cases, self-injurious behavior. Males with autism are more likely to demonstrate externalizing behaviors in childhood, such as hyperactivity.
These differences likely reflect a combination of factors, including socialization and differences in expectations, as well as underlying neurobiological differences. In other words, differences in brain development between males and females may partially explain why females present differently than males.
When Should Parents Consider an Evaluation?
Routine screening for signs of autism can, and should, be completed by your pediatrician during routine well-child visits at ages 18 months and 24 months, using a standardized screening tool, such as the Modified Checklist for Autism in Toddlers Revised (MCHAT-R).
A comprehensive autism evaluation is recommended when multiple symptoms are present, persist over time and across settings, and lead to meaningful impairment in daily functioning.
For more information about the process of evaluating a child for autism, see “What Happens During an Autism Evaluation? A Step-By-Step Guide for Parents”.
How to Support Your Child with Autism
Once a child has been diagnosed with autism, the focus shifts to identifying interventions that will address their needs. While there isn’t a one-size-fits all approach to supporting a child with autism, several specialized interventions are recommended:
Speech and Language Therapy (SLP)
Speech therapy supports both verbal and nonverbal communication. This may include developing spoken language, improving understanding of language (receptive skills), supporting pragmatic or social communication, and using alternative communication methods (e.g., AAC devices) when needed.
Occupational Therapy (OT)
Occupational therapy focuses on helping children participate more comfortably and effectively in daily activities. This can include sensory processing differences (sensory aversions and sensory-seeking behavior), fine motor skills (e.g., writing, using utensils), self-care skills (e.g., dressing, bathing, feeding), and emotional regulation and transitions.
Applied Behavior Analysis (ABA) and Related Approaches
Applied Behavior Analysis (ABA) is one of the most widely studied approaches for supporting children with autism. It focuses on reinforcing helpful behaviors and building skills through structured teaching and repetition. Within this broader category, there are different models of intervention.
Early Intensive Behavioral Intervention (EIBI) is a more traditional, structured form of ABA, typically delivered in a high-intensity, one-on-one format. In contrast, more naturalistic, developmentally informed approaches—such as the Early Start Denver Model (ESDM)—integrate behavioral principles into play-based, relationship-focused interactions that occur in more natural settings.
These approaches differ in style and structure, and families often have preferences based on their child’s needs, their own values, and the type of learning environment that feels most appropriate.
A Strengths-Based Approach
While it is natural to focus on areas of difficulty, it is equally important to recognize and support a child’s strengths. Many children with autism have areas of strong interest, attention to detail, creativity, or unique ways of thinking and problem-solving. A strengths-based approach involves identifying and building on what a child already does well, supporting development without trying to change core aspects of identity, and creating environments where the child can feel competent and understood. This perspective can help shift the focus from “fixing” differences to supporting growth in a way that is both effective and respectful.
Identifying Resources for Parents and Children
Accessing the right resources can make a meaningful difference for families navigating early concerns about autism. These may include:
Early intervention programs (often available through state or local services for children under age 3)
School-based services through early childhood special education programs
Parent education and support groups, which can provide both practical guidance and community
Developmental specialists, including pediatricians, child psychiatrists, developmental pediatricians, and psychologists
Final Thoughts
It is entirely valid for parents to seek guidance, and answers, when they notice differences in their child’s development. When considering autism in a young child, it can be helpful to keep in mind that each child is truly unique. Every child has their own strengths to build on and challenges to address, and long-term outcomes can vary considerably. At the same time, earlier identification and access to appropriate supports can play an important role in a child’s developmental trajectory.
Frequently Asked Questions
What are the early signs of autism in toddlers?
Early signs of autism in toddlers may include differences in eye contact, limited response to name, reduced use of gestures such as pointing, delayed or atypical speech, repetitive behaviors, strong preference for routines, and unusual responses to sensory input.
At what age can autism be identified?
Autism can often be identified in early childhood, with some signs emerging as early as 12–18 months. Routine screening is recommended at 18 and 24 months, though some children are diagnosed earlier or later depending on how symptoms present.
How is autism diagnosed in young children?
Autism is diagnosed based on a pattern of symptoms across social communication and behavior that are present over time and across settings. No single symptom is enough to make a diagnosis. A comprehensive evaluation typically includes developmental history, observation, and standardized assessments.
What should I do if I notice signs of autism in my child?
If you have concerns, it is reasonable to discuss them with your child’s pediatrician. If multiple symptoms are present and persist over time, a comprehensive developmental evaluation may be recommended.
Can autism symptoms change over time?
Yes. A child’s developmental profile can change over time, especially with support and intervention. Some children make significant gains in communication, social skills, and daily functioning.
Do boys and girls show autism differently?
In general, boys are more likely to show externalizing behaviors such as hyperactivity, while girls may show fewer overt repetitive behaviors and more subtle social differences. These patterns are not universal and can vary across individuals.
What types of therapy are used for autism?
Common therapies include speech and language therapy, occupational therapy, and behavioral or developmental interventions such as ABA, EIBI, and ESDM. The best approach depends on the individual child’s needs.
Will my child be okay if they are diagnosed with autism?
Children with autism have a wide range of developmental paths. With appropriate support, many children make meaningful progress over time. Focusing on strengths, while addressing areas of need, can help support long-term development.
Megan Bowers, MD, PhD is a child, adolescent, and adult psychiatrist specializing in neurodevelopmental disorders, and is the founder of Bowers Integrative Psychiatry and CEO and Medical Director of The Mind Grove TMS Center. Her work focuses on integrative approaches to mental health, combining evidence-based medication management with lifestyle and mind–body interventions.
The information provided on this website is for educational purposes only and is not intended as medical advice. It should not be used to diagnose or treat any condition. Please consult a qualified healthcare professional for individualized medical guidance. Use of this website does not establish a physician–patient relationship.
