A developmental delay isn’t always the same as autism in toddlers

By Lisa Jo Rudy 

 Medically reviewed by Diana Apetauerova, MD

Just as there are traits that suggest your child might be autistic, there are common developmental signs indicating your toddler is not autistic.

A toddler who responds to their name, copies spoken words, and waves "bye-bye," for instance, is developing normally. It's unlikely they have an autism spectrum disorder (ASD), a diagnosis that involves a pattern of traits and behaviors.1 These autism traits cannot be explained by other physical, intellectual, or mental disorders.

You may be concerned that your child displays some autism traits. However, keep in mind that children develop at their own pace and a single delay or odd behavior isn't usually a sign of an autistic toddler.

This article discusses milestones that indicate your child is developing normally. It also describes patterns of behavior and actions your child might display that seem to align with (but are likely not caused by) autism.

Signs Your Toddler Is Not Autistic

All children develop at their own pace. However, there are common developmental milestones that pediatricians will look for at well visits. If your child misses these milestones, it may indicate a developmental delay but not necessarily autism.

For example, in a child who misses one or two of these milestones, it may be related to premature birth or managing a medical challenge such as low hearing.

If your child has achieved the following by their third birthday, they are unlikely to receive an ASD diagnosis:

• They make eye contact most of the time

• They respond to their name

• They copy your actions and words

• They can speak in simple sentences

• They ask questions

• They engage in pretend play

• They show empathy

Ruling Out Autism

Autism is a pattern of traits that interfere with a child's normal functioning, sometimes with intense traits and limitations. A single trait does not lead to an autism diagnosis.

In fact, to be diagnosed with autism, a child must meet the following criteria, showing limitations or delays in all three areas of social communication and in two of four areas of repetitive behaviors.2

Social Communication and Social Interaction

1. A child displays persistent problems with social communication and interaction in multiple settings. This is evident in the following ways:

• They don't show social or emotional back-and-forth communication with others, including an inability to initiate a conversation.

• They have poor nonverbal communication skills including lack of eye contact or lack of facial expressions.

• They are unable to maintain relationships, which may include an inability or a disinterest in playing games with peers.

Intensely Focused, Repetitive Patterns of Behavior

2. A child displays behaviors such as:

• They repeat motor movements, repeat words or phrases, engage in echolalia, or line up objects over and over again.

• They insist on a common routine and these routines might become ritualized.

• They become fixated on a certain object.

• They have an unusual response to sensory experiences (touch, sight, sound, smells, or tastes).

Further Criteria

3. Autism traits must be present during early development.

4. The traits must impair the child's social life.

5. The traits and their impact cannot be explained by other delays or medical conditions.

Having just one of the behaviors listed would not lead to an autism diagnosis. However, you should always discuss concerns about your child's development with their healthcare provider.

Behaviors That Don't Necessarily Point to Autism

It's common to wonder whether a child's unusual tendencies or quirks are just personality traits, delays that shouldn't be a concern, or part of a pattern due to autism spectrum disorder. The following are behaviors that may worry you, but these are not always indicators of autism.

Doesn't Respond to Your Call

Your child interacts with you and others and has normal play habits and sensory responses, but doesn't respond to your voice when they have their back turned away from you.

You may see this on a list of autism traits to watch for, but alone, this is not a reason for concern. However, this is common among children who are engaged in an activity. If the lack of response persists, discuss it with your pediatrician to check for hearing loss or other issues.

Develops Traits After Early Childhood

If your child developed and behaved like most children until they reached the age of 6 or older, then they likely do not have an autism spectrum disorder, even if traits emerge at a later age.

To be diagnosed, your child must have first shown autism traits at an early age, even if those traits only caused problems in later years.1 A brand new trait at age 12 or 14 may look a little like autism, but the likely cause is something else.

When children get to school, some parents begin to see learning delays or an inability to keep up with neurotypical peers. While these traits may be part of a learning disorder and should be evaluated, this is not a clear indication that your child has undiagnosed autism.3

Fixates on Specific Interests or Hobbies

A child who only seems interested in very specific or unusual subjects or hobbies is not necessarily autistic. Similarly, an early talent for math, music, or some other activity doesn't usually mean a child has autism although many people assume that.

Many autistic people hyperfixate on certain subjects and show special talents at a young age, but on their own, these are not autism traits.1 It may mean your child is highly intelligent and creative.

Talks Later Than Most Kids

It's true that many (but not all) autistic children are late talkers. Some never learn to talk at all. But if your child develops normally except for not yet using spoken words, autism is not the likely problem.

Speech delays can be the result of many factors. Your child may have hearing problems or other issues that impact the brain, such as aphasia.4 This can affect the part of the brain that controls language.

The pace at which children develop language skills can also differ. Many of these issues can be treated or even cured. Meanwhile, there is a good chance that your child's speech will progress in its own time just fine.

If this issue persists, talking with your child's healthcare provider can help address these delays in a timely manner. Some delays related to speech may be signs of a sensory processing disorder (SPD). These include1

• Not babbling or using words on time

• Lack of eye contact

• Lack of engagement when you're interacting with your child

Prefers Being Alone

You've heard autistic children tend to be introverts. By and large, that's true. But so are many other people.

There could be many reasons why your child is not overly social. Some of these may be due to real issues while others are not.

For instance, some children (and adults) feel overwhelmed when their senses are overly fired up. A great deal of noise or light can prompt them to withdraw.

Some also prefer to quietly read or draw instead of running around with peers. If your child's development is otherwise on pace but they seem to prefer being alone, shyness may be the real reason they appear aloof.

But if you feel that something more is going on, ask for your child to be assessed. You may need to address sensory processing issues or some other problems to help them feel less anxious when they socialize with others.

Lines Things Up

Autistic kids often like to arrange objects and toys a certain way. In fact, these activities often take the place of real, symbolic play.

But the desire for order by itself is not an autism trait. If your child lines things up but also plays in usual ways, chances are they simply like to create order from chaos.

If you have concerns, keep a good eye on your child to see whether they line up objects for a reason, or whether it appears to be compulsive. Try to also observe whether they like to play pretend or other games with you or their peers.

If your child develops typically in other ways, you may have no cause for concern. If you are worried, it is worth your while to consult with your child's healthcare provider.

Testing for Early Autism Traits in Toddlers

If your child exhibits multiple developmental delays or unusual behaviors, make an appointment with their pediatrician. If your child does have autism, it's important to get a diagnosis as soon as possible so you can obtain support and therapy that will help them develop strategies for learning and communication. 

Before your appointment, make a list of your child's behaviors and delays, and be sure to relay these to your child's healthcare provider. You may also find it helpful to bring a list of questions to your appointment.

If your child's pediatrician suspects autism, they may refer you to one or more ASD specialists, which might include a developmental pediatrician, a child psychologist, and a speech and language specialist.

Before your child can be diagnosed, they may undergo testing such as:

• Cognitive testing

• Speech and language testing

• A developmental evaluation

You may also be asked to complete a screening questionnaire that will help your child's healthcare provider understand their cognitive, language, and movement skills. 

Your child's healthcare provider will likely also want to monitor them as they grow and develop to see if they are meeting certain milestones.

Summary

Certain actions or behaviors your child shows (or does not show) may cause you to question whether they might have autism.

Your child may not engage with you or others in the way you expect and may prefer to play alone instead. In fact, they may ignore you more often than not when you attempt to call out to them.

Bear in mind that common developmental milestones are meant to be a guide. They are not set in stone. Your child will learn and progress at their own pace and may interact and play with others in their own way.

Share your concerns with your child's healthcare provider if these issues persist. They can help you pinpoint what may be causing these issues and work with you on a care plan to help your child overcome these issues.

4 Sources

National Institute of Mental Health. Autism spectrum disorder.

Centers for Disease Control and Prevention. Autism spectrum disorder (ASD): Diagnostic criteria.

Centers for Disease Control and Prevention. Learning disorders in children.

Centers for Disease Control and Prevention. Language and speech disorders in children.

Additional Reading

Centers for Disease Control and Prevention. Signs and symptoms of autism spectrum disorder.

Harstad L, et al. Early warning signs of autism.

By Lisa Jo Rudy
Lisa Jo Rudy, MDiv, is a writer, advocate, author, and consultant specializing in the field of autism.