Understanding autism

Signs in children

Autism signs in children

Spotting the early signs of autism in young children can be hard if you’re not an autism expert.

Many of these signs are common to all young children but they are seen more often in children who have autism.

We’ve listed here some common red flags for autism – if your child shows some of these then it’s time to check in with a qualified professional.

We also list typical developmental milestones which may be used as a guide to gauge a child’s development. If there are any concerns about a child’s development, or if there is a loss of any skills at any age, talk to a doctor as soon as possible.

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For a more detailed information regarding signs in children, click here to visit our dedicated resource Autism: What Next?
toddler boy with autism looking at camera slightly smiling

“When my son was 18 months old, a friend brought her 9 month old baby round to our house. I had so much fun with the baby; there was a constant interaction between us. I realised this was completely absent with my own little boy.”

Signs in toddlers

Expected developmental milestones:

12 months

  • Watches faces intently, responds to other people’s expressions of emotion
  • Smiles, imitates some facial expressions, follows moving object with eyes
  • Begins to babble, imitates sounds and words, brings hand to mouth
  • Has single words like “dada”, repeats sounds or gestures for attention
  • Turns head toward direction of sound, responds to own name
  • Pushes down on legs when feet placed on a firm surface; raises head and chest when lying on stomach
  • Smiles at mother or primary care-givers voice, prefers them over all others
  • Can sit up without assistance, can pull self up to stand, walks holding on to furniture
  • Waves ‘bye-bye’ and points to objects

24 months

  • Walks alone, with support can negotiate stairs and furniture, carries and pulls toys while walking
  • Has several single words by 15 to 18 months; uses simple phrases by 24 months
  • Imitates behaviour of others, excited about company of other children

36 months

  • Uses 4-5 word sentences, understands most sentences and instructions
  • Imitates adults and playmates, expresses affection openly, separates easily from parents
  • Sorts objects by shape and colour
  • Plays make believe
  • Climbs well, runs, kicks a ball, negotiates stairs unaided

Speak to your doctor if:

By 12 months your child

  • Does not pay attention to or frightened of new faces
  • Does not smile, does not follow moving object with eyes
  • Does not babble, laugh and has difficulty bringing objects to the mouth
  • Has no words
  • Does not turn head to locate sounds and appears not to respond to loud noises
  • Does not push down on legs when feet placed on a firm surface
  • Does not show affection to primary caregiver, dislikes being cuddled
  • Does not crawl, cannot stand when supported
  • Does not use gestures such as waving or pointing

By 24 months your child

  • Cannot walk by 18 months or walks only on his toes, cannot push a wheeled toy
  • Does not speak; does not imitate actions, cannot follow simple instructions
  • Does not appear to know the function of common household object such as a telephone by 15 months

By 36 months your child

  • Has very limited speech, does not use short phrases, has difficulty in understanding simple instructions
  • Has little interest in other children, has difficulty separating from mother or primary care-giver
  • Difficulty in manipulating small objects
  • Has little interest in ‘make-believe’ play
  • Frequently falls, has difficulty with stairs

Resist the temptation to minimise concerns

Infographic describing negative reactions to autism diagnosis

Common signs of ASD in preschoolers

With some children, the signs of autism might not become entirely obvious until they reach preschool (or even school age), when suddenly the developmental gap between them and their peers becomes more pronounced.
In addition to the signs for babies/toddlers, here are some of the more common ways ASD might present itself in a preschool-aged child.

Social communication red flags

  • The child generally does not point to or share observations or experiences with others
  • The child tends not to look directly at other people in a social way. This is sometimes referred to as a lack of eye contact
  • There may be an absence of speech, or unusual speech patterns such as repeating words and phrases (echolalia), failure to use ‘I’, ‘me’, and ‘you’, or reversal of these
  • Unusual responses to other people. A child may show no desire to be cuddled, have a strong preference for familiar people and may appear to treat people as objects rather
    than a source of comfort
  • The child may appear to avoid social situations, preferring to be alone
  • There is limited development of play activities, particularly imaginative play
  • There may be constant crying or there may be an unusual absence of crying

Behavioural red flags

  • The child often has marked repetitive movements, such as hand-shaking or flapping, prolonged rocking or spinning of objects
  • Many children develop an obsessive interest in certain toys or objects while ignoring other things
  • The child may have extreme resistance to change in routines and/or their environment
  • The child may be resistant to solid foods or may not accept a variety of foods in their diet
  • There are often difficulties with toilet training
  • The child may have sleeping problems
  • The child may be extremely distressed by certain noises and/or busy public places such as shopping centres
preschool aged girl with autism looking at camera smiling slightly

“She was so distant from us we found it hard to engage her. We would have to say her name at least six times before she would acknowledge us, often staring into space as if in a trance. We put this down to a hearing problem but test results showed otherwise.”

Signs of ASD in primary school aged children

Children are often diagnosed with autism once they get to school, when their social communication and behavioural characteristics mark their development out as different to their peers.

  • Issues with conversation, perhaps dominating conversations with their favourite topic and not knowing how to take turns
  • Not being able to interpret the non-verbal communication of peers and adults
  • Unusual speech patterns, a monotonous tone or an old fashioned way of talking
  • Seeking solitude, and finding being with others very stressful and exhausting
  • Being rigid in following rules at school and in sport and games
  • Finding it hard to read social cues and the unwritten rules of friendship
  • Having unusual interests and obsessions, no breadth of interests
  • Sometimes there are unusual physical movements, such as touching, biting, rocking or finger flicking
  • Having sensory issues, either heightened or lack of sense of smell, touch, taste, sound and vision
  • Need to follow routines to feel secure, become very upset when expected routines change
  • Having few or no real friends
  • Aggression is sometimes seen, usually as a way of avoiding overwhelming situations
  • Anxiety is also common, especially as children enter the teenager years
young teenage boy with autism looking at camera slightly smiling

“Really didn’t know until it was suggested to us by the school counsellor who recommended we have our child assessed.”

Screening tools and tutorials

There are some great screening tools and tutorials to help parents and carers spot the early warning signs for autism. Below are some we highly recommend. Please be mindful that they are just screening tools, and not a diagnosis.

Early autism detection - ASDetect

This is a free app that empowers parents and caregivers to assess the social attention and communication behaviours of their children younger than 2½ years (between 11 and 30 months).
This video-led self-assessment app is based on comprehensive, rigorous, world-class research conducted at the Olga Tennison Autism Research Centre

ASDetect app on mobile phone

The app guides parents and carers through each assessment using a combination of videos and questions, as well as activities that you can do with your child. Once you have completed an assessment, you receive both an on-screen result of either ‘low’ or ‘high’ likelihood of autism, as well as a comprehensive formal assessment results email. See more asdetect.org/

Early signs of autism tutorial Kennedy Krieger Institute

This free 9-minute video tutorial on ASD behavioural signs in one-year-olds. The tutorial consists of six video clips comparing toddlers who show no signs of ASD to toddlers who show early signs of ASD.

Each video is presented with voice-over explaining how the specific behaviours exhibited by the child, as they occur on screen, are either indicative of ASD or typical child development.

Autism: What Next?

The first free digital toolkit - a central hub to help individuals and families navigate the first year following an autism diagnosis.

Visit here