Autism in children: early signs, from babies to school age

Seeing your child do things differently from other children can stir up a lot of feelings at once. You might feel worried, guilty or afraid of making a fuss over nothing. Many parents pick up on something long before anyone else does, because they see their child every day. Looking into it is a sensible step, and it isn’t a judgement on your child or on your parenting.

What does autism look like in children?

In children, autism shows as differences in how a child communicates, behaves and reacts [1]. Those differences stand out when you compare your child with other children of the same age. Every autistic child is different, and many won’t show every sign, while some signs aren’t obvious at all [1]. Some children’s signs are spotted when they’re very young, and others aren’t picked up until much later in life [1].

What counts is a set of differences that keeps showing up over weeks and months, rather than one unusual day. A toddler who lines up toys one afternoon is simply playing.

Autism is something a child is born with, and it isn’t an illness [2]. It isn’t caused by vaccines or medicines either [2]. For the condition itself, start with what autism is. Our guide to autism symptoms covers signs at every age, adults included.

Signs of autism in babies: the first year

Signs of autism are rarely visible in a newborn [3]. A US study that followed 50 babies from 6 months to 3 years helps explain why [3]. At 6 months, the babies later diagnosed autistic looked very much like the others. They looked at faces, smiled and made sounds towards people about as often as other babies did [3]. Over the following months these behaviours dropped away, and by 12 months the differences were clear on most measures [3].

From late in the first year and into the toddler years, you might see some of these things:

• Not responding to their name, even though their hearing is fine [4].
• Fewer shared smiles, and less response to your face or your feelings [4].
• Not smiling back when you smile at them [5].
• Few gestures, such as pointing, and little babbling [4].
• Very strong reactions to sounds or textures, or hardly any reaction at all [1].

If several of these keep showing up, mention them to your health visitor.

Signs of autism in toddlers and preschool children

Between 2 and 4 is often when a parent, nursery worker or health visitor first spots something. Speech, play and friendships are all growing fast at this age, so differences start to show. In a toddler or preschool child, you might see:

• Late talking, such as fewer than ten words by age 2 [4].
• Repeating set words or phrases, which is sometimes called echolalia [4].
• Not pointing to show you things, or not looking where you point, which is known as reduced joint attention [4].
• Little pretend play, or preferring to play alone rather than with other children [1].
• Repeated play or movements, such as opening and closing doors, rocking or hand flapping, sometimes called stimming [1].
• Strong distress at changes in routine [1].
• Strong food preferences, such as eating only certain textures [1].

Some children lose words or social skills they used to have. If you see this, talk to your GP or health visitor soon. NICE says a child under 3 who loses these skills should be referred to an autism team [6].

Signs of autism in school-age children and teenagers

Older children show many of the same signs as younger ones [1]. School makes bigger social demands, though, so differences can become easier to see. In a child at school or a teenager, you might see:

• Few close friends, and more time spent alone [1].
• Taking things literally, or missing sarcasm [1].
• Very formal speech, or talking at length about their own interests instead of chatting back and forth [4].
• Needing rules to be followed, and getting upset when they aren’t [1].
• Finding change hard, such as the move from primary to secondary school [1].
• Strong reactions to noise, lights, smells or textures [4].

For some children, struggles at school or worries about their mental health are what first lead to a closer look [5]. A child can seem to manage for years before that point arrives.

How to use a checklist of autism signs

A checklist can’t tell you whether your child is autistic. Only an autism assessment can give a reliable answer [5]. Where a checklist helps is in putting what you’ve seen into words. Showing a written list of signs to your GP or another professional can help when you talk about a referral [5].

Professionals weigh how strong the signs are, how long they’ve lasted and whether they show both at home and at nursery [6]. So it’s worth jotting down when and where you see each sign.

For toddlers, one screening tool is the M-CHAT-R/F, used to judge how likely autism is [7]. Parents fill in a checklist, and a follow-up interview is held for children it flags [7]. A US study of more than 16,000 toddlers, screened at 18 and 24 months, found it picked up many autistic children [8]. Even so, fewer than half of the children it flagged were diagnosed autistic [8]. Almost all of them did have some developmental delay or concern [8]. In the UK, screening every child for autism isn’t recommended, because no test is yet good enough for the whole population [9].

Why are signs of autism in children sometimes missed?

Signs are often missed when a child doesn’t match the picture people expect. Autism can be under-recognised in girls, and missed in children who talk well or have a learning disability [6]. A child’s own coping strategies, or a supportive home or school, can hide signs too [6]. Good eye contact, smiling, showing affection, pretend play or talking on time don’t rule autism out either [6].

Some children learn to hide their differences, which is called masking, and it can be exhausting [1]. Some hold it together all day at school, then let it all out at home. Autistic girls may copy how other children play and seem to cope socially [1]. Boys can mask too, so masking isn’t only something girls do [1]. Our guide to how autism can look in girls goes into more detail.

What to do if you notice signs in your child

Your GP can explain how assessment works locally, though the school or a health visitor may refer instead [10].

An assessment with AuDHD Psychiatry may help if:

• your child is aged 6 to 17.
• the signs have shown at home and school for a long time.
• they make school, friendships or family life harder.

It might not be right today if:

• your child is under 6: start with your GP or health visitor.
• you need urgent help now. Call NHS 111 and choose the mental health option, or in Northern Ireland call Lifeline free on 0808 808 8000, any time. In an emergency, call 999 or go to A&E [11].

At AuDHD Psychiatry, the autism assessment for children is online, over three appointments, and a parent can be present. If ADHD may be part of it, our child assessment for ADHD and autism together covers both. If you’re not ready to book, there are two free first steps. You could start with the free autism test for teenagers aged 12 to 15, a screen, not a diagnosis. Or ask questions on a free 15-minute call, which is for information only.

Questions parents ask

In short

Autism tends to show gradually over a child’s early years, and in some children not until school. No two autistic children are quite alike. A checklist helps you describe what you’ve seen. Your GP, health visitor or your child’s school is the place to start. Take your notes on what you’ve seen, and where, to that first conversation. If your child is 6 or older, AuDHD Psychiatry can also assess them online.