Red Flags for Autism Spectrum Disorders
As a parent, it is important to understand the warning signs related to Autism Spectrum Disorders. Being aware of the red flags for Autism Spectrum Disorders can lead to earlier diagnosis for your child which means earlier intervention.
New Research Related to Screening for Autism
Previously, clinical professionals began screening toddlers for autism spectrum disorders at 18 months and 24 months old; however, recently, research has demonstrated that autism screening can be completed as early as 12 months old. In fact, even the Autism Diagnostic Observation Schedule – Second Edition (ADOS-2), a semi-structured standardized assessment for Autism Spectrum Disorders, now includes a toddler module which can be conducted with children as young as 12 months old.
Domains for Autism Spectrum Disorders
When evaluating children for an Autism Spectrum Disorder, three main areas are assessed including social interaction, communication, and repetitive behaviors and restricted interests. In each of these areas, parents may observe delays or impairments for their child that are concerning.
Please keep in mind that Autism Spectrum Disorders have a wide range of symptom severity meaning that Autism Spectrum Disorders can present very differently across children.

Social Interaction Red Flags
Children who are diagnosed with Autism Spectrum Disorders have difficulties with socialization, interaction, and play with other children. At a young age, you may notice that your child:
- Rarely greets familiar people
- Rarely chooses to interact with others by handing toys
- Prefers to be alone
- May not like affection
- May resist being touched by familiar people
- May not appear interested in other children
- Does not appear interested in sharing interests with you, such as showing you something
- Does not react to others’ emotions or feelings
- Avoids making eye contact with others
- Not engaging in any pretend or imaginative play by around 18 months old
Again, it is important to understand the severity spectrum for Autism Spectrum Disorders. While some children diagnosed with Autism Spectrum Disorders avoid interaction with all peers, other children may approach children but their interactions appear “awkward.”
Communication Red Flags
Many individuals with Autism Spectrum Disorders also have communication deficits ranging from completely nonverbal (meaning that the child does not speak any words) to verbally fluent. Early red flags for Autism Spectrum Disorders in the communication domain include:
- Delays in learning how to speak
- Typically-developing children begin to babble around 4-6 months old, start to speak in single words around 12 months old, and then progress to short phrases between 18 and 24 months old.
- Not responding to name as it is called
- Repeating words or phrases over and over again, known as “echolalia.”
- Difficulties communicating wants and needs to others
- Children with Autism Spectrum Disorders may have trouble using gestures, such as pointing to objects, to express themselves.
- Using an odd tone of voice, abnormal volume, or pitch while talking
- Making up own words
Restricted and Repetitive Interests Red Flags
Children diagnosed with an Autism Spectrum Disorder also have what is defined as restricted, repetitive patterns of behavior, interests or activities. This includes:
- Engaging in repetitive motor behaviors such as hand flapping, rocking, or spinning in circles
- Becoming distressed with a slight change in routine
- Playing with objects in a way that the objects were not intended, such as lining up toys
- Intense fascinations with certain objects or interests
- Hypersensitivity (over-reactivity) or hyposensitivity (under-reactivity) to sensory experiences, such as smell, taste, touch, pain, or sight
Getting Your Child Tested for an Autism Spectrum Disorder
If you are concerned that your child may have an Autism Spectrum Disorder or developmental delays, ask your child’s pediatrician to refer you to a provider that can complete a comprehensive evaluation.
Diagnoses for Autism Spectrum Disorder are considered to be the most valid when they are based on multiple sources of information including observations, interview with parents/caregivers, and semi-structured standardized assessments (such as the ADOS-2).

