Autism signs and traits can be challengeing to identify on your own because autism looks different person-to-person. Autistic children might have only a few characteristics and behaviors listed below while others might have many.

Early Signs of Autism in Infants & Toddlers (0–3 years old)

When identifying autism, many diagnostic providers prioritize looking at the time between the ages of 4 and 5, but common signs of autism start showing up in the first few years of a child's life.¹

During their first year, babies with autism may:

• Be sensitive to touch and dislike being held or cuddled
• Not show affection with big smiles or joyful expressions
• Not make noises to get your attention like with babble or “baby talk”
• Not use gestures to point at things
• Not make eye contact
• Not respond to their name
• Not crawl
• Seem not to hear when others talk to them

Toddlers with autism (about the age of 2 to 3) may:

• Use a limited set of words, gestures, and sounds or not speak at all
• Show a keen interest in particular subjects or activities
• Show repetitive movements like flapping their hands or spinning
• Repeat certain noises like grunting or throat clearing
• Show little interest in playing with other children or prefer to play alone
• Have difficulty making friends or understanding others' thoughts and feelings
• Seem aloof or indifferent
• Not walk or walk only on their toes
• Be obsessed with their unique routines 
• Be only interested in functional play like categorizing and stacking
• Not be interested in pretend play like cuddling stuffed animals or walking action figures
• Show self-harming behaviors like head banging or biting
• Struggle to follow simple instructions
• Not notice or care if others are upset

Autism Signs in School-Aged Children and Teenagers (4–18 years old)

Older children with autism generally have challenges with social communication, repetitive behaviors, and special interests. Some have unique sleeping and eating patterns and experience sleeping and digestion issues.^2-3

Autistic children and teenagers experiencing social differences may:

• Not notice or take an interest in what’s going on around them
• Find it challenging to connect with others or make friends
• Have difficulty understanding feelings or talking about them
• Not play “pretend” games
• Not share their interests or achievements with peers and parents
• Prefer to stay alone most of the time or struggles with continuing play with peers
• Lack fear or shows too much fear

Autistic children and teenagers experiencing speech and language differences may:

• Speak in an unconventional tone, rhythm, or pitch and possibly sound like a Disney princess or end every sentence as if asking a question
• Start speaking or babbling much later than other children
• Repeat certain words or phrases over and over
• Memorize and repeat lines from television shows or movies
• Find it difficult to communicate their needs and desires
• Have challenges following simple directions
• Respond to questions by repeating them back instead of answering

Autistic children and teenagers experiencing nonverbal communication difficulties may:

• Seem to have challenges with balance or coordination
• Not make consistent eye contact
• Seem detached and not respond to attempts to attract their attention
• Find it difficult to regulate their facial expressions and show expressions that don’t match what they are saying
• Find it difficult understanding others' facial expressions, gestures, and tone of voice
• Respond unexpectedly to some noises, smells, or textures where they are very sensitive or completely unresponsive to loud noises

Autistic children and teenagers showing repetitive behaviors and special interests may:

• Follow a strict routine and find difficulty with change, like being a picky eater
• Develop attachments to unusual objects like rubber bands or light switches
• Have obsessive interests in unique, narrow topics, like sports statistics or train schedules
• Have sensory issues like refusing to wear clothes with tags or being sensitive to noise
• Spend a long time focusing on moving objects or specific parts of toys
• Engage in self-stimulatory behavior (stimming) like rocking or twirling
• Get upset by minor changes like changing the order of their toys
• Exhibit unique posture or mannerisms like arching their back while sitting or walking only on toes

Does autism look different by gender?

In some cases, cisgender girls (a person whose gender identity is the same as their sex assigned at birth) may show different or fewer characteristics of autism compared to cisgender boys. While most of the signs mentioned above are common for both genders, some can be harder to spot in girls. 

Girls with autism often hide certain traits very well, known as “masking” or “social camouflaging,” and spend a lot of energy trying to adapt to social norms. Research shows that girls with autism are generally more successful in forming friendships. Studies also show that girls with autism are much less likely to engage in visible repetitive behaviors than boys.⁴ All of this makes it harder to identify autism in some girls, and essential to be aware of certain traits. 

Girls with autism may:

• Be unusually passive with peers or at school
• Rely on peers (usually other girls) to speak on their behalf or guide them
• Seem at risk of depression, anxiety, and mood swings
• Find social communication increasingly tricky, especially as they enter their teen years
• Seem exhausted after social interactions and need a lot of time to recuperate
• Seem to get frustrated easily, immediately shut down or zone out during meltdowns

Our culture of stereotypes may also be responsible for autistic girls not being identified as such at a young age. For example, if a girl is shy and withdrawn, she might be seen as more "feminine,” but a boy with the same differences would get referred for help. In the same way, girls who seem distracted may be called "dreamers" in a positive sense, while this behavior in boys would be something to be addressed. Because of these societal conventions, signs of autism often get covered up as "typical" behavior for girls.⁵

It’s important to note that more research is needed to understand how to identify autism in transgender and nonbinary people. In a 2020 study, people who didn’t identify with the sex they were born with reported more autistic traits and were five times more likely to believe they have undiagnosed autism.⁶

Conclusion

If you see any concerning signs, the next step is to complete a free screener online or schedule a diagnostic evaluation with a doctor. Diagnostic evaluations can be expensive without insurance or if you go to an out-of-network provider. You can find in-network specialists here.