Early Signs of Autism in Babies, Infants, and Toddlers

Early Signs of Autism in Babies, Infants, and Toddlers


Here at ThinkPsych, we often get asked by concerned parents or relatives whether a child is displaying any signs of Autism Spectrum Disorder (ASD). While an official diagnosis should be done by a licensed practitioner such as a developmental pediatrician or a licensed clinical psychologist, it is important for parents to be aware of early warning signs of developmental issues. If you notice any of these warning signs, please speak with your doctor as soon as possible.

Signs of Autism Typically Begin Before 24 Months of Age

Although early ASD symptoms may not be obvious to an untrained observer, skilled clinicians and researchers can detect the first signs of autism as early as 6 to 12 months old. However, definite diagnosis usually cannot be made until at least 18 months old. The reason for this discrepancy is that although early signs may indicate the possibility of ASD, your child is still in a period of rapid development and may “catch up” to developmental milestones by 18 or 24 months old. As a result, if you notice some of the earliest signs (e.g., before 12 months), you should not panic. However, it is important to start a conversation with your doctor about your concerns.

Earliest Signs of Autism in Babies (At 6 Months Old):

  • Doesn’t laugh, smile, or show affection for caregivers
  • Poor or no eye contact

Early Signs of Autism in Infants (At 12 Months Old)

  • Little or no babbling
  • Few or no communicative gestures such as pointing, showing, reaching, or waving
  • Doesn’t respond to name
  • Doesn’t follow gestures of others (e.g., pointing to an object across the room)

Early Signs of Autism in Toddlers (At 18 Months Old)

  • Doesn’t have at least six words
  • Stereotyped or repetitive behaviors such as hand flapping, rocking, spinning
  • Unusual or repetitive use of objects such as spinning, lining up, and rotating.
  • Lack of functional use of toys (e.g., rolling a car across a table)
  • Doesn’t imitate adults or other children

Signs of Autism in Older Toddlers (18-24 Months Old)

  • Very little or no language at all
  • Avoidance of eye contact
  • Loss of previously acquired speech
  • Persistent repetition of words/or phrases without communication purpose
  • Excessively restricted interests
  • Difficulty with minor changes in routine
  • Sensory difficulties such as intense reactions to sounds, smells, tastes, textures, etc.

If you are reading this list and believe that your child may have some or many of these symptoms, it is important to take the first step of completing a more comprehensive screening. Please take the free Modified Checklist for Autism in Toddlers (M-CHAT) here. The M-CHAT is an empirically validated tool for developmental screening of toddlers age 16-30 months. This tool will help you determine whether you should consult with your doctor about a further evaluation. If the results indicate a high probability for Autism, please talk to your doctor as soon as possible, because early intervention for Autism is absolutely critical. If your child is diagnosed with ASD, please see our post here for additional resources for parents with newly diagnosed children.


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