Signs of autism can be visible in toddlers from around 12 to 18 months. These include reduced eye contact, limited joint attention, delayed speech and unusual responses to sensory input. This guide explains what to look for and when to seek advice.
Signs of autism can sometimes be identified in toddlers from around 12 to 18 months, though many autistic children are not identified until the preschool years or later. The developmental checks carried out by health visitors include screening for some early autism signs. Parents and carers are often the first to notice that something seems different about their toddler’s development, even if they cannot yet name what that difference is. Trusting parental instincts and seeking professional advice promptly, rather than waiting to see whether differences resolve, is important for ensuring early support.
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Reduced eye contact is one of the most commonly described early signs of autism in toddlers. Typical infants engage frequently in eye contact as part of social interaction. Some autistic toddlers make notably less eye contact than typical peers, though others make eye contact in some contexts. The significance of eye contact in autism assessment is as part of a broader social communication profile, not as a single indicator.
Joint attention is the ability to coordinate attention with another person around a shared object or event. Behaviours indicating joint attention include pointing to share interest, following another person’s point or gaze and showing objects to others. Limited or absent joint attention by 12 to 18 months is one of the earliest and most consistent signs of autism in toddlers.
The absence of babbling by 12 months, no single words by 16 months and no two-word phrases by 24 months are milestones whose absence warrants referral for assessment. While speech delay can have many causes, it is also a common feature of autism. Any loss of previously acquired language or social skills at any age is a significant sign that warrants urgent assessment.
Toddlers who show unusually strong responses to sensory input, whether over-responsive or under-responsive, may be showing an early sign of autism. This might include strong distress at everyday sounds, intense sensitivity to certain textures, seeking out intense sensory input or appearing not to notice pain. Sensory differences in toddlers are worth discussing with a health professional.
Repetitive behaviours in toddlers that may suggest autism include lining up toys rather than playing imaginatively, repetitive spinning or banging of objects, hand-flapping or other repetitive movements, strong insistence on specific routines and intense distress when routines are changed. These behaviours serve regulatory and interest functions for autistic toddlers.
Parents or carers who have concerns about their toddler’s development should speak to their GP or health visitor promptly. There is no benefit in waiting. Early identification and support produce better outcomes. Coming prepared with specific examples of the behaviours or differences noticed, including when they were first observed, is helpful.
For related information see our articles on Recognising Autism Signs in Children and Autism Diagnosis Process.
Signs of autism may be visible in some toddlers from around 12 to 18 months, particularly in relation to joint attention, eye contact, early language development and responses to sensory input. Many signs become clearer as children get older. A formal autism assessment is possible in toddlers, but diagnosis may be confirmed later as development progresses.
Pointing to share interest is an important early communication milestone typically emerging around 12 months. Its absence or significant delay by 12 to 18 months is one of the most consistently identified early signs of autism and warrants discussion with a health professional. A health professional needs to assess the full developmental picture rather than basing assessment on any single sign.
Any regression in previously acquired language or social skills at any age is a significant developmental concern that warrants urgent assessment. Speak to your GP as soon as you notice regression in your child’s communication or social skills.
Visit our Understanding Autism hub for more guides on signs, diagnosis, causes, sensory needs, masking and co-occurring conditions.
The information in this article is provided for educational purposes only and is not intended as medical advice. If you have concerns about autism or any neurodevelopmental condition, speak to a qualified healthcare professional. SENDhelp Education Limited accepts no responsibility or liability for any loss or damage arising from reliance on this content. Any links to third-party websites are provided for convenience only and do not constitute endorsement of their content.