The age and severity of early signs of autism diagnosis vary widely. In their first months, several infants give clues. Behaviors are evident in others as late as age 2 or 3. Not all autistic children exhibit all of the signs. Even kids who don't have a couple of display autism. It is for this reason that professional appraisal is crucial.
By 6 months
- Few or no big smiles or other warm, joyful, and engaging expressions
- Limited or no eye contact
By 9 months
- Little or no back-and-forth sharing of sounds, smiles, or other facial expressions
By 12 months
- Little or no babbling
- Little or no back-and-forth gestures such as pointing, showing, reaching, or waving
- Little or no response to the name
By 16 months
By 24 months
- Very few or no meaningful, two-word phrases (not including imitating or repeating)
At any age
- Loss of previously acquired speech, babbling, or social skills
- Avoidance of eye contact
- Persistent preference for solitude
- Difficulty understanding other people’s feelings
- Delayed language development
- Persistent repetition of words or phrases (echolalia)
- Resistance to minor changes in routine or surroundings
- Restricted interests
- Repetitive behaviors (flapping, rocking, spinning, etc.)
- Unusual and intense reactions to sounds, smells, tastes, textures, lights, and/or colors