autism red flags

Red Flags or Absolute Indicators for Young Children


  • No big smiles or other warm, joyful expressions by 6 months or after
  • No back-and-forth sharing of sounds, smiles, or other facial expressions by nine months or after
  • No babbling by 12 months
  • No back-and-forth gestures, such as pointing, showing, reaching, or waving by 12 months
  • No words by 16 months
  • No two-word meaningful phrases (without imitating or repeating) by 24 months
  • ANY loss of speech or babbling or social skills at ANY age

Red Flags or Absolute Indicators for Older Children/Adults

  • Failure to develop peer relationships appropriate for developmental level
  • Appropriate language skills, but not using language in a socially appropriate way
  • Stereotyped and receptive use of language or idiosyncratic language
  • Preoccupation with an interest that is abnormal in its intensity or focus
  • Inflexibility, with a “need” for nonfunctional routines or rituals