What Age Does the Brain Develop in Autism?

Early brain development in autism: faster, not slower

It all starts earlier than most people think

So, here’s something that genuinely surprised me when I started reading more deeply into autism research: the autistic brain often develops faster than the neurotypical brain — at least in the early stages.

We're talking as early as 6 months to 2 years old. That’s the period when a child’s brain typically experiences rapid growth, and in many autistic kids, this growth is even more intense. It’s not just about size (though studies show autistic toddlers can have larger brain volumes), but how the brain wires itself.

I remember chatting with my colleague, Daniel, whose nephew was diagnosed at 18 months. He told me, “We thought he was just really focused… turns out, that intense focus was already part of how his brain was developing differently.”

Brain overgrowth and pruning: what goes differently?

The pruning process is key — and often altered in autism

Okay, imagine your brain is like a garden. At birth, it’s planted with way too many connections. Over time, your brain "prunes" the ones it doesn't need — kind of like trimming branches so the tree grows stronger.

In autistic brains, this pruning process seems to happen differently. Either it’s delayed, or it’s less efficient. Which means more neural connections stick around — sounds good, right? Not always.

More connections can mean more sensory input, more information flooding in, and often, a tougher time filtering or organizing thoughts. That’s why sensory overload can be such a big deal for people on the spectrum.

Adolescence and the second wave of brain changes

Puberty hits differently — and the brain adapts again

This part? Honestly, it caught me off guard. I thought brain development slowed down after childhood. But teenage years bring a second wave of reorganization.

And for autistic individuals, this can be a tough phase — emotionally, socially, and neurologically. The prefrontal cortex (responsible for planning, decision-making, and social behavior) is still developing. But the way it develops in autistic teens can diverge sharply from neurotypical peers.

One parent told me, “My daughter went from being a quiet, focused kid to someone who couldn't stand being in a crowded hallway. We didn’t expect such a big shift at 14.”

Turns out, that’s not uncommon.

Is brain development “delayed” in autism?

Not really delayed — just different

I’ll be honest: this term annoys me. A lot.

Calling it a delay implies there’s only one “correct” timeline. But research shows autistic brains don’t follow a slower version of the same path. They take entirely different routes — sometimes earlier, sometimes later, sometimes just… parallel.

Think of it like two trains on different tracks. One isn't late — it’s just going somewhere else.

Can therapies or environments influence development?

Yes, but not in the way people often expect

People ask me all the time: “Can early intervention change brain development in autism?” And the answer is yes — to a degree. But we have to be realistic.

You’re not “curing” autism or forcing the brain into a neurotypical mold (and honestly, you shouldn’t try to). But what you can do is create an environment that helps the autistic brain adapt, cope, and thrive.

That means structure. Predictability. Respect for sensory needs. And a whole lot of patience.

A friend of mine, Carla, told me her son didn’t speak until 6 — and now he’s writing short stories. “We just kept supporting his way of thinking, not pushing him to mimic others,” she said. That stuck with me.

Final thoughts: the autistic brain grows on its own terms

If you’re wondering when the autistic brain develops, the real answer is: it never stops — just like any other brain. But the timeline, the intensity, and the connections? They follow a unique rhythm.

So instead of thinking about "fixing" development, think about understanding it. Supporting it. And letting it bloom in its own way.

Because honestly, the diversity of brain development is part of what makes humanity so incredible. And autism is one of the clearest (and most fascinating) examples of that.

Is 165 cm normal for a 15 year old?

The predicted height for a female, based on your parents heights, is 155 to 165cm. Most 15 year old girls are nearly done growing. I was too. It's a very normal height for a girl.

Is 160 cm too tall for a 12 year old?

How Tall Should a 12 Year Old Be? We can only speak to national average heights here in North America, whereby, a 12 year old girl would be between 137 cm to 162 cm tall (4-1/2 to 5-1/3 feet). A 12 year old boy should be between 137 cm to 160 cm tall (4-1/2 to 5-1/4 feet).

How tall is a average 15 year old?

Average Height to Weight for Teenage Boys - 13 to 20 Years

How to get taller at 18?

Staying physically active is even more essential from childhood to grow and improve overall health. But taking it up even in adulthood can help you add a few inches to your height. Strength-building exercises, yoga, jumping rope, and biking all can help to increase your flexibility and grow a few inches taller.

Is 5.7 a good height for a 15 year old boy?

Generally speaking, the average height for 15 year olds girls is 62.9 inches (or 159.7 cm). On the other hand, teen boys at the age of 15 have a much higher average height, which is 67.0 inches (or 170.1 cm).

Can you grow between 16 and 18?

Most girls stop growing taller by age 14 or 15. However, after their early teenage growth spurt, boys continue gaining height at a gradual pace until around 18. Note that some kids will stop growing earlier and others may keep growing a year or two more.

Can you grow 1 cm after 17?

Even with a healthy diet, most people's height won't increase after age 18 to 20. The graph below shows the rate of growth from birth to age 20. As you can see, the growth lines fall to zero between ages 18 and 20 ( 7 , 8 ). The reason why your height stops increasing is your bones, specifically your growth plates.