Autism Red Flags

Not every child with ASD has deficits in all areas that are screened. Some children may have words, while others may not make many sounds at all. Some may always smile when having fun while others lack affect. After a screening, we will share results with you and give you examples of what was observed that may indicate further evaluation, including a formal psychological evaluation from a medical professional.

When reviewing this list and asking yourself if your child demonstrates these symptoms, keep in mind that skills you want to see should be rated based on performance on a daily basis, consistently occurring with different familiar people and in a variety of settings. A child with ASD may not demonstrate many of these symptoms, but only a few but the symptom occurs enough for you or others to notice the difference between your child and other children his or her age.

It is important to remember this is just a short list of examples that could indicate “red flags.” There are many factors that go into an Autism Spectrum Disorder diagnosis. You know your child best. If you think, “Something isn’t right,” then it’s best to gain peace-of-mind and schedule a screening.

Social Skills

Examples of social issues related to ASD:

  • Does not respond to name by 12 months of age
  • Avoids eye-contact
  • Prefers to play alone
  • Does not share interests with others
  • Only interacts to achieve a desired goal
  • Has flat or inappropriate facial expressions
  • Does not understand personal space boundaries
  • Avoids or resists physical contact
  • Is not comforted by others during distress
  • Has trouble understanding other people’s feelings or talking about own feelings

Typical infants are very interested in the world and people around them. By the first birthday, a typical toddler interacts with others by looking people in the eye, copying words and actions, and using simple gestures such as clapping and waving “bye bye”. Typical toddlers also show interests in social games like peek-a-boo and pat-a-cake. But a young child with an ASD might have a very hard time learning to interact with other people.


Each child with ASD has different communication skills. About 40% of children with an ASD do not talk at all. About 25%–30% of children with ASD have some words at 12 to 18 months of age and then lose them. [1]

Examples of communication issues related to ASD:

  • Delayed speech and language skills
  • Repeats words or phrases over and over (echolalia)
  • Reverses pronouns (e.g., says “you” instead of “I”)
  • Gives unrelated answers to questions
  • Does not point or respond to pointing
  • Uses few or no gestures (e.g., does not wave goodbye)
  • Talks in a flat, robot-like, high-pitched or sing-song voice
  • Does not pretend in play (e.g., does not pretend to “feed” a doll)
  • Does not understand jokes, sarcasm, or teasing

Children with ASD who do speak might use language in unusual ways. They might not be able to put words into real sentences. Some children with ASD say only one word at a time. Others repeat the same words or phrases over and over. Some children repeat what others say, a condition called echolalia. The repeated words might be said right away or at a later time. For example, if you ask someone with ASD, “Do you want some juice?” he or she might repeat, “Do you want some juice?” instead of answering your question. Some children with an ASD can speak well but might have a hard time listening to what other people say.

Children with ASD might have a hard time using and understanding gestures, body language, or tone of voice.

Children with ASD might say “I” when they mean “you,” or vice versa or say, “Are you okay?” when he or she falls. Their voices might sound flat, robot-like, or high-pitched. People with an ASD might stand too close to the person they are talking to, or might stick with one topic of conversation for too long. They might talk a lot about something they really like, rather than have a back-and-forth conversation with someone. Some children with fairly good language skills speak like little adults, failing to pick up on the “kid-speak” that is common with other children.

Unusual Interests and Behaviors

Many children with ASD have unusual interest or behaviors.

Examples of unusual interests and behaviors related to ASD:

  • Lines up toys or other objects
  • Plays with toys the same way every time
  • Likes parts of objects (e.g., wheels)
  • Is very organized
  • Gets upset by minor changes
  • Has obsessive interests
  • Has to follow certain routines
  • Flaps hands, rocks body, or spins self in circles

Repetitive motions are actions repeated over and over again. They can involve one part of the body or the entire body or even an object or toy suck as spending a lot of time repeatedly flapping their arms or rocking from side to side or repeatedly turn a light on and off or spin the wheels of a toy car. These types of activities are known as self-stimulatory or “stimming” behaviors.

Other Symptoms

Some children with ASD have other symptoms. These might include:

  • Hyperactivity (very active)
  • Impulsivity (acting without thinking)
  • Short attention span
  • Aggression
  • Causing self injury
  • Temper tantrums
  • Unusual eating and sleeping habits
  • Unusual mood or emotional reactions
  • Lack of fear or more fear than expected
  • Unusual reactions to the way things sound, smell, taste, look, or feel

Children with ASD might have unusual responses to touch, smell, sounds, sights, and taste, and feel. For example, they might over- or under-react to pain or to a loud noise. They might have abnormal eating habits. For instance, their diet may only consist of only a few foods (e.g., chicken nuggets, fries, and mabye one or two fruits or vegetables). Others might eat nonfood items like dirt or rocks (this is called pica). They might also have issues like chronic constipation or diarrhea.

Children with ASD might have unusual sleeping habits. They also might have abnormal moods or emotional reactions or a very limited range of emotions. For instance, they might laugh or cry at unusual times or show no emotional response at times you would expect one. In addition, they might not be afraid of dangerous situations, or they could be fearful of harmless objects or events.


  1. Lord C, Risi S, DiLavore PS, Shulman C, Thurm A, Pickles A.Autism from 2 to 9 years of age. Arch Gen Psychiatry. 2006 Jun;63(6):694-701.