Warning Signs of Autism in Children that Parents Should Know

warning signs of autism

Warning Signs of Autism in Children that Parents Should Know

Remember the phrase ‘forewarned is forearmed?’ Having an early diagnosis can help your child have an advantage. Early intervention can help minimize any disability or developmental delay. Autism or Autism Spectrum Disorder (ASD) is an increasingly well-recognized and accepted neurodevelopmental disorder. ASD is characterized by abnormalities in social interaction, social communication, repetitive patterns of behaviors, and restricted interests and/or activities.

The impairments caused by Autism/ASD can range from mild to severe. As a rule of thumb, the more severe the impairment or symptoms, the earlier it is diagnosed. Hence a significant number of people with milder impairments with ASD, miss out on getting the right kind of help and support and may only be diagnosed in their adulthood. With mounting awareness about the soaring prevalence of ASD i.e. approximately 1 in 50 children are being diagnosed with ASD, there has been an accompanying increase in the evidence base, of advantages of early identification and treatment to minimize the impairments of autism/ASD.

In this article, I have listed some of the warning signs or pointers that parents/carers can look out for, right from the first few months of infancy. I have grouped these by both age groups and by aspects of autism/ASD.

How to spot the warning signs of Autism/ASD?

Before we discuss the warning signs of autism, it is important to know about how best to spot or notice these warning signs. As every child grows at their own pace, it can be tricky to detect the early warning signs of ASD.

However, with due care and observation, parents can measure their child’s social and emotional progress against standardized age-specific developmental charts or milestone tables.  Doing so will help to understand whether their child is acquiring the skills in the broadly average range or whether they are well behind their age-appropriate peers. If a given child is falling behind in developing and acquiring age-appropriate milestones, then it is crucial to keep your child under close observation of a healthcare professional such as your health visitor or a keyworker at a nursery/early years setting. Should your child fail to catch up with their peers over the next 4-6 months or should the child continue to diverge from their peers regarding their development, then seek professional help or reach out for appropriate expertise.

Clinical research shows that there are some early signs and pointers for detecting or suspecting autism/ASD in children from an incredibly young age. Please read on to see a brief overview of what these are.

Warning signs of ASD according to age group

There are several aspects of behavior or functioning when it comes to identifying autistic traits among children. The fundamental factors to consider would be a given child’s social understanding, verbal ability, language acquisition, communication, behaviors, interests, and activities. Children who have ASD are often found to show developmental delay or deviation in the above areas, from as early as 6 months of age. Here are some typical ASD traits observed in children with autism, arranged by their age group:

Ages 0-1

    • Signs of autism can be detected in babies from as early as 3 months, becoming progressively evident as they grow.
      • Lack of facial expression or social smile
      • Lack of paying attention to new faces
      • Lack of searching for sound with eyes
      • Unaware of their name being called
      • Lack of laughter, squealing, or display of affection
      • Lack of intention or ability to attract attention
      • Lack of interest in typical baby games like Peekaboo
      • Minimal babbling or lack of single words
      • Lack of/minimal use of gestures like waving, nodding, or pointing
      • Indifference to new environments or minimal exploration by eyes
      • Lack of interest/exploration with toys or objects
      • Delay in their ability to sit, stand or crawl, in addition to some of the above
      • Lack of interest in small children other than own siblings
      • Lack of interest in the activities of others


Ages 1-2

    • As the child grows, many of the above signs become more pronounced and easily noticeable. The following signs are frequently observed in children diagnosed with ASD:
      • Lack of imitation such as clapping hands
      • Not obeying simple requests such as ‘pass me the cup’
      • Lack of interest or engagement in sharing a storybook with parent/carer
      • Lack of use of words to request articles of food or drink
      • Disinterested in listening to stories
      • Lack of constructive play with boxes or toys
      • Reduced listening and understanding of words and vocabulary
      • Limited play
      • Delay inabilities to use spoon/fork, drink from a cup or help with dressing
      • Sensory difficulties with certain sights, sounds, smell or textures
      • Exaggerated behaviors, aggression or displays of temper

Dr. Rebecca Landa -Director of the Kennedy Krieger Institute’s Center has developed a video tutorial on ASD behavioral 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 explains how the specific behaviors exhibited by the child, as they occur on screen, are either indicative of ASD or typical child development.

Ages 2-4

    • After many of the above concerns have been brewing for a significant length of time, many parents seek help after the child’s 2nd birthday. Hence, more children are diagnosed with ASD between the ages of 2-4. In addition to all the symptoms mentioned above, toddlers with autism/ASD in this age group, are considered by some further traits:
      • Lack of ability to assist with small household tasks or put away toys on request
      • Inability to give their first name, gender, or age
      • Lack of ability to name a dozen objects
      • Inability to put 2-3 words together to communicate or request
      • Inability to name a few colours or count numbers to 6
      • Reduced understanding in terms of big/little, long/short etc
      • Inability to feed self with a spoon and/or a fork without help
      • Increased crying and temper tantrums
      • Repetitive behaviour and mannerisms such as flapping hands
      • Aversion to or distress with the change in routine
      • Regression in speaking and recalling words
      • Poor comprehension i.e. giving unrelated answers to questions asked
      • Demonstrating little or no awareness of danger
      • Increase in obsessive interests or unusual behaviours


Warning signs according to features of ASD

The warning signs or red flags in children suspected of autism/ASD can also be grouped into each feature of this condition such as a child’s communication abilities, social interaction abilities, and behaviour. So, they have been grouped under:

    • Red flags in communication

      • Lack of/minimal babbling
      • Delay in the understanding of language ability
      • Delay in expressive language ability
      • Lack of intent to communicate
      • Use of odd words or phrases or odd tone and voice pitch
      • Impaired use of eye gaze and gestures e.g. lack of ‘nodding head’ for ‘yes’
      • Echoing of words without understanding their meaning
      • Impaired turn-taking in conversation
      • In school years, difficulty in understanding humour, sarcasm, or deception
      • Literal interpretation and difficulty with idioms and jokes
      • Limited use of gestures or mime to convey meaning
      • Reticence to start or continue a conversation


    • Red flags in social interaction

      • Not pointing to objects to show interest
      • Not look at objects’ others point to
      • Limited or no eye contact when interacting with others
      • Disinterested or indifference to social hugs and affection
      • Absent or limited interest in social interaction with peers
      • Lack of response to smiles or mirror facial expressions
      • Lack of ability to perceive or read others gestures and expressions
      • Limited imitation of others in play or in life
      • Lack of curiosity or interest in others
      • Restricted social play
      • Limited pretend play or imaginative activity


    • Red flags in behaviour

      • No shared interest
      • Content playing by themselves or content in their own company
      • Narrow, specific, and intense interests e.g. Dinosaurs, Thomas the Tank Engine, Pokémon, TV listings, Football teams, Train schedules
      • Fixated with personal interests
      • Prefer repetitive activities and games
      • Stereotypical behaviour such as rocking, spinning, twirling, hand flapping, etc.
      • Playing with parts of a toy, and not the entire toy in a way that is intended
      • Extreme reaction to transition or change in routine
      • Hyper/hyposensitivity to certain smell, sight, sounds, tastes, textures
      • Easily disturbed by loud or unpredictable sounds
      • Hyper or hypo sensitive to pain, etc.

In addition to the above signs or pointers to autism/ASD, there is yet one more important marker that should alert parents/carers. And that is ‘regression’. Regression can be one of the forms of presentation of autism/ASD, when a child who appears to be developing normally, loses their previously acquired skills to communicate, speak or interact with others.

What to do if you suspect your child has autism?

What to do if you suspect your child has autism?

This can be a stressful time. However, the first thing to do is not to panic. Next, discuss your concerns with your child’s key worker in a nursery/early year setting or contact your health visitor. You could also speak to your general practitioner (GP) regarding your concerns.

Your health visitor or GP may decide to monitor closely for a period i.e. 3-4 months or refer you to a neurodevelopmental or community paediatrician. Alternatively, you could seek a private referral if you are concerned about the long wait for an assessment.

You should then collate all the information about your child i.e. reports from nursery, your health visitor’s report and any other health or developmental record you may have on your child and take these to your appointment with the paediatrician.

A developmental paediatrician will be able to carry out a comprehensive neurodevelopmental assessment and devise an individualised management plan that builds on your child’s strengths and address their unique needs. There are numerous behavioural, educational, environmental, and occasionally some medical interventions can be implemented to address the above-mentioned impairments of autism/ASD. Early assessments can help to have prompt and timely interventions. These interventions can minimise your child’s difficulties and enormously helpful in improving their behaviour and functioning.


  • Autistic Traits and Symptoms by Age – Autism Spectrum Disorder and Autistic Traits in the Avon Longitudinal Study of Parents and Children: Precursors and Early Signs 2012 (Bolton et. al.)
  • Early Signs and Symptoms of Autism in Children, by Feature 2007 (Clare J Dover, Ann Le Couteur)
  • ‘Developmental Delay’ Reconsidered: The Critical Role of Age-Dependent, Co-variant Development
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