How two brothers can both be autistic while presenting in very different ways– and why understanding the autism spectrum matters.
When people hear that both of my sons are autistic, they often assume autistic siblings experience autism in the same way.
Not necessarily.
In fact, one of the biggest things our family has taught me is that autism really is a spectrum. Two autistic children-even brothers- can meet the same diagnostic criteria while having completely different strengths, challenges, personalities and support needs
Our eldest showed what many people would recognise as the more “classic” presentation of autism in boys. Our youngest has many autistic traits too, but they emerged differently and at different ages.
This isn’t about comparing them or suggesting one is “more autistic” than the other. It’s about showing just how varied autism can be – and hopefully helping another parent who is wondering whether what they’re seeing “counts.”
Because sometimes it does.
A note before I begin
Our eldest (“Little Man”) received an informal autism diagnosis around his second birthday and is now almost six years old.
Our youngest (“Little Brother”) has recently turned two and, due to changes in the diagnostic pathway where we live in London, is still waiting for a formal assessment. However, both his nursery and the professionals around him agree that autism is the likely explanation for his development and presentation.
Having already travelled this road once, we know the diagnostic criteria well. This isn’t our first rodeo.
Little Man: The autism signs were there from the beginning
Looking back, I was searching for answers from around four months old.
Even then, I knew something felt different.
Despite this, I was repeatedly reassured that I was simply experiencing what “all parents” experience. But deep down, I knew this wasn’t typical.
Sleep was incredibly difficult
From his very first days, Little Man slept for a maximum of around six hours in every 24-hour period.
He wouldn’t fall asleep in the pram. Instead, he screamed until he was held.
Sleep deteriorated even further at six months.
For years we experienced double-digit night wakings. Many weren’t brief wake-ups either—he would often be awake for hours, requiring constant rocking or breastfeeding before sleeping for only minutes at a time. Those years were exhausting. And he still wakes a lot now- but it still isn’t comparable to these years.
The first time he actually fell asleep “by himself” whilst sat in the pram after a day out, he was around two years old. I still remember how shocked I felt!
Everyday life felt impossible
Shopping wasn’t a simple errand.
Stopping in queues often resulted in complete overwhelm.
I struggled to do weaning, as he wouldn’t tolerate not being held long enough for me to do the most basic of meals.
As he got older, staying at home wasn’t any easier than going out. He followed me from room to room crying and found independent play incredibly difficult.
Interestingly, babywearing transformed things. Our sling became an essential piece of equipment because movement and closeness regulated him in ways nothing else could.
Even now, at almost six, he still prefers me close by and rarely plays independently when I’m home.
His autistic traits were noticeable very early
Some of the behaviours I noticed included:
- toe walking
- arm flapping
- repetitive movements and visible stimming
- intense emotional responses
- lining toys up
- repetitive play
- hand-leading rather than pointing
- staring rather than responding when strangers greeted him
- distress around hair washing
- sensory differences
- strong reactions to small changes
Sometimes we only understood the cause of his distress afterwards.
Perhaps we’d unknowingly put different shoes on after nursery.
Or we’d parked next to a car with tinted windows.
What looked like “random behaviour” always had a reason.
Development happened differently
One thing I’ve learned is that autistic development isn’t always delayed- it can simply happen differently.
I still remember:
- seeing him dance for the first time aged three
- hearing him ask his first question around three-and-a-half
- watching skills appear months or even years after we’d expected them
He has largely toilet trained himself, taught himself to read and even taught himself to ride a bike. Those milestones may have come later than some children, but seeing how independently he mastered them reminds me of the incredible strengths autism can bring.
Today he is funny, affectionate, incredibly social, deeply curious and exceptionally clever.
He’s also still autistic.
He’s made extraordinary progress, but autism hasn’t disappeared.
He still struggles with sleep, attention, executive functioning and cognitive flexibility. What has changed is his development- not who he is.
Little Brother: A completely different autism profile
Our youngest has taught me that no two autistic children are the same.
For the first few months, I genuinely thought he was neurotypical
Compared with his older brother, he slept well initially, happily fell asleep in the pram and seemed much calmer overall.
He laughed.
He danced.
He enjoyed peekaboo.
He tolerated being held by other people.
If he’d been my first child, I probably would have described him simply as “highly sensitive.”
Things began to change around 10 months
Around ten months old, his presentation shifted.
We began noticing:
- repetitive movements
- downward-dog stimming
- side-eye stimming
- increasing sensory sensitivities
- distress during every clothing change
- distress during every nappy change
- screaming during every hair wash
- increasing difficulty with transitions
By 15 months, I was confident he was autistic too. This is why I am such a strong advocate for listening to parents when they describe patterns of behaviour they are seeing, even before a child turns two. Parents often notice subtle differences in their child’s development long before a formal diagnosis is possible. Can you tell if a child is autistic before the age of two?
Some things are the same as his brother
Although their presentations differ, they also share many autistic traits.
Both boys as toddlers:
- struggled with independent play
- have very high co-regulation needs
- were highly distressed waiting in queues
- become distressed when routines change unexpectedly
- line objects up
- enjoy repetitive play
- don’t use many gestures
- have limited response to their names
- prefer exploring environments over playing with toys
- experience speech and language differences
- significantly low pain threshold with teething
And many of these remain true for them both today, though they may express these challenges differently.
There are important differences too
Little Brother doesn’t toe walk. Never has.
He doesn’t arm flap as frequently.
He doesn’t have the same facial expressions that I remember seeing constantly in his brother. But he does do a lot more visual stimming!
His meltdowns tend to be easier to soothe.
His speech delay is actually more significant than his older brother’s was at the same age.
Yet he also has beautiful autistic traits that make me smile every day.
One of my favourites is watching him become completely captivated by leaves moving in the wind.
He has done this since he was tiny. It’s almost impossible not to stop and watch with him.
Autism really is a spectrum
Living with two autistic children has shown me just how misleading stereotypes can be.
People often imagine autism as fitting neatly into “high-functioning” or “low-functioning” boxes, or assume it has to be obvious to count.
The reality couldn’t be further from the truth.
Two siblings.
Same family.
Same diagnosis.
Completely different profiles.
Neither child is “more autistic.”
They’re simply different.
And that’s exactly what the spectrum, and the concept of “spikey profiles” means.
What I wish more people understood
The hardest part hasn’t always been autism itself.
It’s been society’s misunderstanding of autism.
When Little Man was a baby, we were often made to feel we’d caused his distress.
We heard suggestions that we’d spoiled him.
That we’d breastfed too much.
That he was hungry.
That we’d picked him up too often.
That every parent was tired.
That all babies cry.
Early understanding and earlier intervention wouldn’t have changed who he is.
But it would have changed how supported we felt.
Parents shouldn’t have to spend years wondering whether they’re imagining things.
They shouldn’t have to defend themselves against outdated myths while trying to support a child who is clearly struggling.
Every autistic child deserves to be understood
Today my biggest concern isn’t whether my children are autistic.
I already know they are.
My concern is how we help them stay true to themselves while giving them the support they need to thrive. How we are parents get the support we need, to be able to support them fully. What ever parent wants.
Autism brings incredible strengths, joy, curiosity and ways of seeing the world that deserve to be celebrated.
It can also bring significant support needs- for autistic people and for the families walking alongside them.
Those two truths can exist together.
The more we understand that autism looks different in every child, the sooner families can stop feeling judged and start feeling supported.
Having two autistic sons with completely different autism profiles has taught me there is no single way for autism to look. Every autistic child deserves to be understood as an individual, not measured against stereotypes or someone else’s experience
Frequently Asked Questions About Autistic Siblings
Can autistic siblings have different traits?
Absolutely. Autism is a spectrum, meaning every autistic person has a unique combination of strengths, challenges and support needs. My two sons are living proof of that.
Can autism look different in the same family?
Yes. Even siblings with the same diagnosis may have very different developmental journeys, sensory needs, communication styles and personalities.
When did I first notice signs of autism?
With my eldest, I began searching for answers around four months old. With my youngest, I didn’t become certain until around 15 months because his presentation was very different.
London Autism Mum 