How to Know If My Child Is Autistic: Early Signs by Age

Avoids eye contact, repeats behaviours or struggles to relate? A child psychologist in Valencia explains the real signs of autism and when to assess.

Does your child avoid eye contact, repeat the same behaviours or struggle to relate? Here are the real signs of autism by age and when to request an assessment.

"He's slow to respond when I call his name." "He doesn't make eye contact like his brother did at this age." "He spends an hour lining up his cars in a row, over and over again." "At the park he doesn't come near other children, he prefers to be alone."

If any of these sentences describe your child, you've very likely already typed the word **autism** into Google. And the search has almost certainly left you more confused than reassured: contradictory information, endless symptom lists, forums with extreme cases that don't match yours.

As a General Health Psychologist specialised in child and adolescent care (Reg. No. CV16625), I want to give you a piece that **won't scare you nor over-reassure you**. Just clear, rigorous and useful. You'll learn to recognise the real signs of autism by age, understand why today we speak of a "spectrum", and decide with clinical criteria when to request a [professional assessment](/servicios/evaluaciones-psicologicas).

What ASD Is (and Why Today We Call It "Spectrum")

**Autism Spectrum Disorder (ASD)** is a neurodevelopmental condition of neurobiological origin that mainly affects two large areas (DSM-5-TR):

1. **Social communication** (interaction, pragmatic language, emotional understanding).

2. **Patterns of behaviour, interests and activities** (very intense interests, routines, repetitions, sensory hypersensitivity).

It is called a "spectrum" because **no two autistic people are alike**. One child may not speak and need full support, while another may get top marks, speak like an adult and only need occasional support in social relationships. Both are autistic.

This is what makes many families hesitate: *"But my child hugs me, looks at me, plays…"*. **Your child hugging or looking at you does not rule out autism**, just as not speaking does not confirm it. The real signs need to be looked at as a whole and by age.

Early Signs by Age

Before 18 months: the first clues

- Doesn't respond consistently when you call their name (with hearing problems ruled out).

- **Little or no social smile** (doesn't return the smile when you smile at them).

- Doesn't point with their finger to ask for things or to share what they see ("look at that").

- Doesn't imitate simple gestures (waving goodbye, clapping).

- Poor sustained eye contact.

18 to 36 months: the key detection window

- **Delayed or absent language** (no meaningful words at 18 months, no two-word combinations at 24).

- Or the opposite: very elaborate but **echolalic** language (repeating phrases from cartoons or adverts out of context).

- Doesn't play symbolically (doesn't feed a doll, doesn't act out scenes).

- **Restricted interests**: obsesses with a single object (wheels, fans, letters, maps) for hours.

- **Repetitive movements** (hand flapping, rocking, walking on tiptoes).

- Very intense tantrums in response to minimal routine changes (a different route to school, a different yoghurt brand).

- **Sensory hypersensitivity**: can't bear certain noises, fabric textures or tastes; or, conversely, seeks intense stimuli (lights, pressure, spinning).

3 to 6 years: when social difference becomes more visible

- At the park or school, **prefers to play alone** or "alongside" other children rather than "with" them.

- Doesn't understand social games (tag, hide-and-seek) or plays them in their own rigid way.

- Talks a lot about their favourite topic without noticing if the other person is bored or wants to change subject.

- Struggles to read gestures, facial expressions or irony.

- Reacts out of proportion to small changes (the teacher sitting in a different seat, mum wearing a new T-shirt).

- Continues to show repetitive movements, alignments or very strict routines.

In girls, teenagers and "masked autism"

This point is vital: ASD in girls is detected much later because they tend to **camouflage** their difficulties (copying their classmates, memorising social scripts, appearing "shy"). They are often identified in adolescence, when anxiety, depression, eating disorders or exhaustion from holding up the mask appear.

If your teenage daughter feels "different", socially exhausted, hypersensitive and with very intense interests, and an ASD assessment has never been considered, it's worth doing one now.

What Is NOT Necessarily Autism

Before getting alarmed, it's worth knowing what can look like ASD without being so:

- Very introverted or shy children.

- Isolated language delays (with no other social signs).

- Children with sensory hypersensitivity without social impact.

- Intense [childhood anxiety](/blog/ansiedad-infantil-senales-sintomas) that limits social interaction.

Sources